the use of limestone aggregate in concrete
Transcription
the use of limestone aggregate in concrete
THE USE OF LIMESTONE AGGREGATE IN CONCRETE MUSFA BIN MOHAMAD UNIVERSITI TEKNOLOGI MALAYSIA THE USE OF LIMESTONE AGGREGATE IN CONCRETE. MUSFA BIN MOHAMAD A project report submitted in partial fulfillment of the requirements for the award of the degree of Master of Engineering (Civil Structure) Faculty of Civil Engineering Universiti Teknologi Malaysia APRIL, 2005 Alfatihah to the passed of my beloved mother and father. To my beloved Tuan Guru, my wife and my daughters. ii ACKNOWLEDGEMENT In preparing this thesis, I was in contact with many people, researchers, academicians, and practitioners. They have contributed towards my understanding and thoughts. In particular, I wish to express my sincere appreciation to my main thesis supervisor, Professor Ir. Dr. Hj. Mohd. Warid bin Hussin, for encouragement, guidance, critics and friendship. I am also very thankful to Dr. Othman Cik Puan, Dr. Aziz Chik, En.Ros Ismail, En. Suhaimi Abdul Rahman and Technicians from Highway laboratory UTM Skudai for their guidance, advices and motivation in doing all the relevant tests. Without their continued support and interest, this project report would not have been the same as presented here. I am also indebted to University Teknologi Malaysia (UTM) for finding my Master study. Librarians at UTM also deserve special thanks for their assistance in supplying the relevant literatures. I am also very thankful to my head of department Majlis Daerah Raub(MDR) Tuan Haji Abdul Rashid Mohamed in preparing this project report, for his advices and also continued support was very much appreciated. My sincere appreciation also extends to my friends En. Arifin bin Siran (Laboratory Assistance Sekolah Menengah Sulaiman Bentong), Ir. Kamaruddin Hassan ( JKR Bridge Section, Kuala Lumpur), Ir. Abdul Kadir Bin Ahyat (Consultant), Ir. Che Husni Ahmad (Consultant), Ir. Azli Shah Bin Ali Bashah iii (Engineer of Dewan Bandar Raya Kuala Lumpur) and my colleagues who have provided assistance at various occasions. Thanking to all of you in advanced. I am also very thankful to En. Adnan (Supervisor of Poh Mix. Sdn. Bhd), En. Ramli Abu Bakar (Senior Technician MDR), En. Khairul Effendi Tuaman(Technician MDR) and others who have provided assistance in preparing and making the cubes tests. Very much thankful is also extends to Engineer Mohd Zaid Bin Abdul Samad (From Petronas) who have provided continued support and assistance in preparing the project report. Lastly, I am also deserve special thanks to my beloved wife for her commitment, encouragement while preparing the works and continued support at various occasions. iv ABSTRACT. Concrete structure is made up of cement, aggregate and water. In building construction the aggregates commonly used are limestone and granite. Three quarters of concrete is made up from aggregate, thus the selection of aggregate should be in the prime condition. To produce a good, strength and high quality concrete the materials used should be in accordance to standard specification. JKR standard specification for building works mentioned that the use of limestone is limited to super structure only whereas for substructure granite aggregate should be used. Due to this problem statement this study is carried out to investigate whether chemical attack in limestone aggregate is the source of problem for sub structure (concrete structure below ground level). This study involved in testing of limestone and granite aggregates. The scope of study includes the investigation on the strength, bonding and chemical attack in the concrete. The main objective of the research is to study the properties of lime stone related to strength and its performances. The method of study to be carried out is through the appropriate test. The types of testing required are sieve analysis, flaky and elongation index test, cube test and aggregate crushing value test. All the tests have been carried out and the results had been recorded in appropriate table and graph. Discussion on the analysis of the results is explained to provide more information about the effect of chemical and the behavior of concrete properties. Lastly the conclusion had been done and one recommendation had been introduced for future work. v ABSTRAK. Struktur konkrit terdiri daripada simen, batu baur dan air. Di dalam pembinaan bangunan, batu baur yang biasa di gunakan ialah terdiri daripada batu kapur dan granit. Tiga suku daripada kandungan konkrit ada lah terdiri daripada batu baur, oleh yang demikian pemilihan batu baur amat lah penting sekali. Untuk menghasilkan konkrit yang baik, kuat dan berkualiti tinggi, maka penggunaan bahan-bahan hendaklah memenuhi spesifikasi piawai. Di dalam spesifikasi Piawai JKR menyatakan bahawa penggunaan batu kapur di hadkan hanya untuk struktur dari tanah keatas sahaja, manakala bagi struktur di bawah tanah hendaklah menggunakan granit. Berdasarkan kepada petikan ini, maka satu kajian untuk menyiasat samaada serangan dari tindak balas kimia merupakan masalah bagi binaan struktur di bawah aras tanah. Kajian ini melibatkan ujian terhadap batu baur jenis batu kapur dan granit. Bidang kajian termasoklah penyiasatan berhubung dengan kekuatan, ikatan dan tindak balas kimia di dalam konkrit. Objektif utama kajian ini adalah untuk mengkaji ciri-ciri batu baur yang berkaitan dengan kekuatan dan keupayaannya. Kaedah kajian ini adalah melalui beberapa ujian yang sesuai. Jenis-jenis ujian tersebut ialah analisis ayakan, indek leper dan indek pemanjangan, ujian kiub dan nilai hancur batu baur. Semua ujian ini telah dijalankan dan keputusannya telah direkodkan dalam bentuk jadual dan geraf. Perbincangan mengenai analisis daripada keputusan ujian akan memberikan maklumat berhubung dengan kesan tindak balas kimia terhadap perilaku dan sifat konkerit. Akhir sekali di sertakan satu kesimpulan dan juga satu cadangan untuk kajian di masa depan. vi TABLE CONTENT CHAPTER 1 2 TITLE PAGE Title Page i Declaration ii Dedication iii Acknowledgement iv-v Abstract vi Abstrak vii Table of Content viii-xi List of Tables xii-xiv List of Figures xv-xix List of Symbols xx List of Appendices xi INTRODUCTION 1.1 Introduction 1-3 1.2 Back ground of the research 3-5 1.3 Significance of the research 5 1.4 Objective of the Study 5-7 1.5 Scope of the research 8-12 LIETERATURE REVIEW 2.1 Introduction 13 2.2 General Information of Aggregate 13-14 2.3 Particles Shape and Texture 14-16 2.4 Bond of aggregate 16 vii 2.5 Theory of rocks 16-17 2.5.1 The Nature of rock 17-18 2.5.2 Igneous rock 18-19 2.5.3 Sedimentation rock 20-22 2.5.3.1 Carbonate rocks 22 2.5.3.2 Limestone(Biochemical) 22-23 3 RESEARCH METHODOLOGY 3.1 Introduction 24 3.2 Experimental framework 24-27 3.3 Experimental Detail 27-29 3.3.1 JKR Standard For Aggregate 29 3.3.1.1 General Aggregate 29 3.3.1.2 Fine aggregate 30 3.3.1.3 Coarse aggregate 31 3.3.2 Aggregate grading 31-32 3.3.2.1 Sampling and testing of aggregate 32 3.3.2.2 Storage of aggregate 33 3.4 Water 33 3.5 Types of test Recommended 33-34 3.5.1 Sieve Analysis Test 34-35 3.5.1.1 Sample of aggregate to be tested 35-36 3.5.1.2 Elongation and Flakiness Index Test 37-39 3.5.2 Concrete Cube Test 3.5.2.1 Preparation of concrete cube grade 3.5.3 Aggregate crushing value test 3.5.3.1 Preparation of limestone aggregate for ACV test 39-40 40-46 46-47 47-53 viii 4 RESULTS AND ANALYSIS 4.1 Introduction 54 4.2 The Results of sieve analysis 54-57 4.2.1 Analysis of the Sieve Analysis Results 58 4.2.2 Analysis of Elongation and 4.3 Flakiness Index Test 58-59 Results of Concrete Cube Test 59-62 4.3.1 Analysis from the results 63 4.3.1.1 Analysis in respect to strength 4.4 4.5 63-67 The results of ACV test 67-68 4.4.1 Test 1 on the 5 January 2005 68 4.4.2 Test 2 on the 5 January 2005 68-69 4.4.3 Test 3 on the 6 January 2005 69-70 4.4.4 Test 4 on the 6 January 2005 70-71 4.4.5 Test 5 on the 6 January 2005 71-72 4.4.6 Test 6 on the 6 January 2005 72-73 Analyzing the results of ACV test 73-74 4.5.1 Analysis of limestone aggregate for 7 days in solutions Mg SO4 + Na NO3 and 7 days in water. 4.5.2 74-76 Analysis of granite aggregate for 28 days in solutions Mg SO4 + Na NO3 and 28 days in water. 5 76-77 DISCUSSION 5.1 Introduction 78 5.2 Discussion on the texture of aggregate 78-79 5.2.1 The source of limestone aggregate 79 5.2.2 80 5.3 Discussion on the Sieve Analysis Discussion on Flaky and Elongation Properties 80-81 ix 5.3.1 What can be discussed on the Flaky and Elongation Properties? 5.4 5.5 6 80-81 Discussion about Concrete Cube Strength 81-82 5.4.1 Cube Strength 7 days period 82-84 5.4.2 Cube Strength 14 days period 84 5.4.3 Cube Strength 21 days 84-85 5.4.4 Cube Strength 28 days 85-87 Discussion on ACV Test results 87 5.5.1 88-92 Discussion on ACV test for 7 days CONCLUSION AND RECOMMENDATION 6.1 Introduction 93 6.2 Conclusion 94 6.3 Recommendation 94-95 REFERENCES 96-98 APPENDICES A – C2 99-103 x LIST OF TABLES TABLE NO. 1.1 TITLE Classification of natural aggregates according to rock type (BS812: Part 1 : 1975) 1.2 PAGE 2 Coarse Aggregate (Nominal Size 20 mm) Standard specification Section 2 to 6 M.S. 7.5) 9 1.3 Testing of aggregate 9 1.4 Minimum Strength Specification of Concrete Cube ( 150x150x150). 2.1 Particle Shape Classification of BS 812: Part 1: 1975 with examples. 2.2 10 15 Compressive Strength of American Rocks Commonly Used as Concrete Aggregates. 17 2.3 Minerals crystallization from magma. 18 2.4 Minerals present in the four main groups of Igneous rock. 19 xi 2.5 Chemistry of selected carbonate rocks sediment. 23 3.1 Date of Cube test. 27 3.2 Fine Aggregate (Natural sand) 32 3.3 Coarse Aggregate (Nominal size 20 mm). 32 3.4 Position of Sieve size 36 3.5 Standard Format for Calculation of Elongation And Flakiness Index Test. 38 3.6 The mix proportion of Concrete Cube Grade 25. 40 3.7 Date of Casting and Testing of Concrete Cube. 44 3.8 Quantity of aggregate/ Mg SO4 + Na NO3 and water Content. 48 3.9 Date of Immersion and Taken out of an Aggregate. 49 4.1 Results of Sieve Analysis of Limestone Aggregate. 55 4.2 Results of the Elongation and Flakiness Index of Limestone aggregate. 57 4.3 Comparison of Aggregate Passing to JKR specification. 58 4.4 The Results of Cubes Test. 60 xii 4.5 The Results of Cube Strength Compare to JKR Specification. 4.6 64 Comparison of Compressive Strength of Rock to Concrete Cube. 66 4.7 Data Record of ACV Test 1 (14-10 sieve). 68 4.8 Data Record of ACV Test 2 (14-10 sieve). 69 4.9 Data Record of ACV Test 3 (20-14 sieve) 70 4.10 Data Record of ACV Test 4 (20-14). 71 4.11 Data Record of ACV Test 5 (14-10) 72 4.12 Data Record of ACV Test 6 (20-14) 73 5.1 The Results of Acv test for Limestone and Granite. 87 5.2 Results of ACV test for Granite and Limestone (28 days). 91 xiii LIST OF FIGURES. FIGURE NO 1.1 TITLE PAGE Sample of limestone aggregate (Source from Kg. Ulu Gali, Raub, Pahang). 2 1.2 Sample of Aggregate. 8 1.3 Sample of concrete cube with 150x150x150 in size. 11 1.4 Sample of Chemical (Magnesium Sulphate + Natrium Nitrate) 12 2.1 How sedimentation rock is formed. 20 2.2 Limestone Rock (Sample 1) 21 2.3 Limestone Rock (Sample 2) 21 3.1 Preparation of Chemical solution 25 3.2 Immersion of cubes in to chemical solution. 26 3.3(a) Front view of Gunong Panas, Ulu Gali, Raub. 28 xiv 3.3(b) Side View of Gunong Panas, Kg. Ulu Gali, Raub. 28 3.4 The Sieve Analysis Apparatus. 30 3.5 Sample of Limestone and granite aggregate in UTM Highway Laboratory. 3.6 31 Source of Limestone from Gunong Panas, Kg. Ulu Gali, Raub, Pahang. 34 3.7 Sample of limestone aggregate for Sieve Analysis Test. 35 3.8 Apparatus in Sieve Analysis Test. 36 3.9 Apparatus for Elongation and Flakiness Index Test (Steel Plate With Standard Hole) 37 3.10 Procedure for Elongation and Flakiness index test 39 3.11 Preparation of Concrete Cubes. 41 3.12 Procedure in Preparation of Cube. 41 3.13 Step to prepare 150x150x150 Concrete Cube 42 3.14 Measuring The Slump of Fresh Concrete 43 3.15 Preparing the concrete cubes 43 3.16 Weighting the Cube Sample 44 xv 3.17 Testing of Cube 45 3.18 Recording Compressive Strength From Dial Gauge 45 3.19 Failure Pattern of Cube. 46 3.20 End of The Test 46 3.21 Weighting of Limestone Aggregate for ACV Test 50 3.22 Placing Aggregate in to the Mould 51 3.23 Aggregate under Testing (400kN/10 minutes) 51 3.24 Aggregate Under Rate of Crushing 52 3.25 Sample of Aggregate after Crushing 52 3.26 Crushed Sample of Aggregate Retain on 2.36 Sieve 53 4.1 Graph of Sieve Analysis Test for Limestone Aggregate 56 4.2 Relationship Between Elongation/Flakiness Index and JKR Standard. 4.3 4.4 57 Limestone Concrete Cube Strength in Chemical Solution for 7 days. 61 Limestone Concrete Cube Strength in Water for 7 days. 61 xvi 4.5 Limestone Concrete Cube Strength in Chemical Solution for 28 days. 62 4.6 Limestone Concrete Cube Strength in Water for 28 days. 62 4.7 Limestone Concrete Cube Strength Compared to JKR Standard for 7 days (Average Strength) 4.8 Limestone Concrete Cube Strength Compared to JKR Standard for 28 days (Average Strength). 4.9 74 Results of Limestone Aggregate Crushing Value Test for 28 days in Chemical Solution and Water. 4.12 67 Results of Aggregate Crushing Value Test for 7 days in Chemical Solution and Water. 4.11 65 Relationship Between Concrete Cube Compressive Strength To Original Rock. 4.10 64 75 Results of Aggregate Crushing Value of Granite for 28 days. 76 5.1 Types of Aggregate Texture 81 5.2(a) Failure Pattern in Water 83 5.2(b) Failure Pattern in Chemical Solution 84 5.3(a) Average Cube Strength of Limestone Concrete 84 in Chemical Solution. xvii 5.3(b) Average Cube Strength of Limestone Concrete in Water. 5.4(a) Results of Limestone ACV Test for 28 days in Chemical Solution and Water. 5.4(b) 90 Results of ACV Test for Granite and Limestone Aggregate in Chemical Solution (28 days) 5.4(d) 89 Results of Granite ACV Test for 28 days in Chemical Solution and Water. 5.4(c) 84 91 Results of Granite and Limestone Aggregate on ACV Test for 28 days in Water. 92 xviii LIST OF SYMBOLS B.S - British Standard > - More than < - Less than G25 - Grade 25 Mg SO4 - Magnesium Sulphate Na NO3 - Natrium Nitrate Ca O - Calcium Oxide Mg O - Magnesium Oxide CO2 - Carbon Dioxide S1,S2,ect - Sample in Chemical Solution S.O - Superintendent Officer ACV - Aggregate Crushing Value JKR - Jabatan Kerja Raya Fe O - Ferrous Oxide Mn O2 - Manganese Dioxide Ca(OH) - Calcium Hydroxide Mpa - Mega Pascal Psi - Ib/square in. Ca CO3 - Calcium Carbonate (Limestone) xix LIST OF APPENDICES APPENDIX TITLE PAGE A1 JKR Specification page 35 99 A2 JKR Specification page 36 100 B JKR Standard Limit for Laboratory Testing 101 C1 Cube Test Results 7 days in Water 102 C2 Cube Test Results 7 days in Chemical Solution 103 CHAPTER 1 INTRODUCTION 1.1 Introduction. Since concrete is the most important part in structural construction, the aggregate content should be in a form of good strength for structural purposes. Concrete is made up of aggregate, cement and water. Through this combination of materials, three – quarter of the mix is governed by aggregate. The aggregate itself is categorized as fine and course aggregate. In this study, the scope of research will be focused on the use of coarse aggregate using lime stone material. Before further discussion, it shall be better to have knowledge and clear understanding about the lime stone material and its properties and performances. Lime stone is one of the aggregate to be used in concrete, other than that are granite, basalt, Quardz, Gneis, Gabbro, Sand stone, Felsit ect. The classification of the aggregates according to BS 812 :Part 1 :1975 as stated from table 1.1 in this chapter. 2 Figure 1.1 : Sample of Limestone Aggregate (Source from Kg. Ulu Gali, Raub, Pahang) Table 1.1: Classification of natural aggregates according to rock type ( BS 812 : Part 1 :1975 ) Basalt Group Flint Group Gabbro group Andesite Chert Basic diorite Basalt Flint Basic Gneiss Basic porphyrites Gabbro Diabase Hornblende-rock Dolerites of all kinds Norite including theralite and Peridotite teschenite. Picrite Epidiorite Serpentinite Lamprophyre Quartz-dolerite Spilite Granite Group Gritstone Group Hornfels group ( including fragmental Gneiss volcanic rocks) Contact-altered rocks 3 Granite of all kinds except Granodiorite Arkose Granulite Greywacke Pegmatite Grit Quartz-diorite Sandstone Syenite Tuff Limestone Group Porphyry Group marble. Quartzite Group Dolomite Aplite Limestone Dacite Ganister Marble Felsite Quartzitic sandstones Granophyre Re-crystallized Keratophyre quartzite. Schist Group Microgranite Phyllite Porphyry Schist Quartz-porphyrite Slate Rhyolite All severely sheared Trachyte rocks. Page 110: Properties of Concrete – A.M. Neville 1.2 Back ground of the research Limestone and granite are two types of aggregates commonly used in industrial construction. For JKR project, the used of limestone aggregate is limited to super structure only whereas for substructure there is no recommended to use limestone below ground level. Due to this statement the study is to be carried out to find what source of the problems in related to concrete below ground level. One of the problems in the ground level is about chemical attack, so 4 that a few numbers of laboratory test should be carried out to get the results for analysis purposes. In conjunction to this matter, the problem arises is based on the JKR specification mention under Section D (Concrete Work) item 3.0 for aggregate contents. From Item 3.3 Coarse Aggregates: Standard Specifications For Building works page 35 standard specification for building works written as below:- “The coarse aggregate shall be crushed hard stone except that for work below ground level, only crushed granite will be used. The aggregate shall not contain clay lumps exceeding 1% by weight. A representative dry sample shall not show an increase in weight exceeding 8% after immersion in water when tested according to the method in M.S. 7.5. It shall be well shaped and not flaky with the flakiness index not exceeding 35%. The maximum nominal size of coarse aggregate shall be 19mm.” Through the statement above, it is understood that the use of limestone aggregate was not recommended in building works below ground level. Since concrete work is the importance structure, understanding about the material properties shall be significantly in the advanced condition. A few tests to get the strength should be carried out in the laboratory and the results can be analyzed. The results obtained can be compared to the standard specification for building’s work. So, through this study I would like to further the use of limestone in a certain area as alternative to granite aggregate. The main reason to study this topic is to get better knowledge and to bare in mind whether “ Chemical Attack below ground level “ source of the problem in using limestone concrete structure. In the preparation of this thesis, many factors should be considered and there must be some references towards the study for getting clear information and understanding about the chemical attack in 5 concrete structure. At the end of this study, a conclusion can be made according to the results obtained through the laboratory tests. 1.3 Significance of the research. In construction industries, the use of aggregates is the most importance material in composition of concrete. Places having granite aggregate should have no problem in construction projects, but for places without granite the problems will be arises and cost incurred become higher. Due to this reason this study should be carried out in the approaching method to overcome the problem as well as beneficial to local people. The advantages of this study are:- i) To provide some information about the used of limestone aggregate. ii) Beneficial and economic value to local people. iii) New finding during the test and methods required to overcome the problems. iv) Have chances to explore the used of local material in construction industries. 1.4 Objective of the study. In our country, stone can be selected from a certain area which is in the form of various types of materials such as granite, limestone, basalt, quardz, gneiss, gabbro, sand stone and others as stated in table 1.0 from the previous paragraph. Area of easily granite formed shall have no problems for concrete structure, but for an area of without granite and limestone easily selected this might be incurred cost to import granite aggregate from other places. As a result, 6 this also will reduce the beneficial economic value for that particular place due to granite demand. The main issue of this study is to identify weather the chemical reaction can affect the concrete structure from limestone aggregate below ground level. In the ground, there are various types of chemical reactions such as sulfate, chloride, nitrate, sodium, atrium and others soluble exist in that particular places. For this purpose, every places will have different soluble in the ground and its depend on the types of soil or rock for that particular area. At the end of this study some information regarding limestone aggregate will be obtained from the test results. Due to the results required, the beneficial values of the study can be shared together and its will bring objectives as the followings:- i) To study the limestone properties related to strength and its performances. In this objective, the strength of the limestone should be obtained in many ways. One of the methods is cube test. However the method pertaining to this matter will be discussed on the next topic under chapter 2 under methodology section. Through this objective, all the information should be collected and might be one of the proven sign to get a solution to the problem. If there is exist, it means that the limestone aggregate is no longer to be a selected and approved material in concrete structure. For this purpose, the specification of JKR should the one to refer and compared with the results of the tests. ii) To compare the results with granite concrete and costing required. As according to JKR specification in building works, the use of granite is the recommended aggregate in construction of JKR projects. For this particular situation, the comparison between limestone and granite is the options to get some information to public use and acknowledgement purposes. 7 Since granite concrete is no matter stronger and its characteristic strength is more than limestone concrete, so that the results of the cube tests is significantly functioning to this study. Because of the local interest to economic value, the cost incurred for both types of aggregate will be established to public information. iii) To provide the information on demands of local material and its benefits. Once the result of the tests is recorded, there are specifics analysis can be ascertained and very important factors to encourage people on the demands of each materials. For this particular objective, the demand on limestone is predictably on advanced because the study is focusing to the local materials on the beneficial aspects especially on the economic aim. However, in promoting the local material demands there must be a specific reason and advantages to welcome people without prejudice. Through this study, it will provide some guide lines and references for really problems arise towards the specific solution otherwise there are no neglected inspiration exists. Once it’s come through there are clear information to people involved in construction industries. iv) As an alternative materials without prejudice. If the concrete made of limestone aggregate can produce a strength and durability, therefore its performance is good for concrete structure. The important thing in construction technology is the material used is followed the specification and the test results should according to specification. Any materials set the specification, meaning that the material can be used for construction purposes. In the case of limestone, it also a type of aggregate involved in obtaining a good concrete provided the required test should followed the specification in the contract document. 8 1.5 Scope of the research. The construction industries are becoming more challenging than ever before. To be competitive, the field of engineering related to the industries has to be established. One of the areas that can be established is the used of material in the construction purposes. A specific scope of study on the limestone aggregate is presented in this paper as to improve the knowledge in the field of construction technology. 1.5.1 Bond of aggregate : The bond between aggregate and cement paste is essential to produce the flexural strength of concrete, but the nature of this bond is not fully understood. For this reason, an analysis needs to be conducted by performing specific tests in the laboratory. The flakiness index and elongation tests on the limestone aggregate are required that to prove the specification in JKR contract document is met. Bonding between aggregate and cement paste depends on the surface of the aggregate. Since the rough surface requires more bonding than the smooth surface, the texture of aggregate to be tested should comply to the requirement of standard specification. Figure 1.2: Sample of aggregates (left is limestone, right is granite). 9 The aggregate used in the tests must comply to the standard grading which is through sieve analysis test with 4 kilogram of limestone aggregate sample. The test shall follow a proper procedure and the results are compared to the standard as tabulated in Table 1.2 below:- Table 1.2: Coarse Aggregate (Nominal Size 20 mm) – Standard specification Section 2 to 6 M.S. 7.5 British Standard 20 mm 10 mm 5 mm 100 25-55 0-10 Sieve Percent passing ( %) The flakiness and elongation tests shall comply to the standard specification listed in Table 1.3 below:- Table 1.3: Testing of aggregate ( Refer Appendix B). Properties Types of Test aggregate Methods Grading Coarse M.S 7.5 As mention in Table 2.1 Elongation Coarse M.S 30 Not exceeding 30% Index Coarse M.S 30 Not exceeding 35% Flakiness Index Coarse M.S 30 Not exceeding 40% Aggregate Crushing Value Limits 10 1.5.2 Strength of Aggregate To get strong and good concrete, the crushing value and cube tests are recommended. Crushing strength of concrete and crushing value of aggregate shall be determined according to a specific strength mentioned in the specification for both limestone and granite. For the granite aggregate, the sample was initially immersed in the water and chemical solution (MgSO4 + NaNO3) for 28 days. The procedure is to discover the effect that water and chemical solution have on the strength of concrete. The crushing value test shall meet the standard in table 1.3 above. The cube strength test shall meet the specification in Table 1.4 below:- Table 1.4: Minimum Strength Specification of Concrete Cube (150x150x150). Equivalent Minimum crushing Maximum Minimum cement nominal Strength at 7 days aggregate content per cubic mix and 28 days after size meter of finished mixing. concrete At 7 days At 28 days N/mm2 1:1:2 (G30) 1:11/2 : 17.0 N/mm2 mm Kg 30 19 380 25.5 19 361 21.00 19 321 3(G25) 1:2:4 (G20) 14.0 11 Figure 1.3: Sample of concrete cube with 150 x 150 x150 in size. 1.5.3 Shulphate Reaction Below Ground Level The chemical attack on the concrete below ground level is proven by immersing the cube samples of concrete grade 25 in solution of Magnesium sulphate plus Natrium Nitrate. The Magnesium Sulphate and natrium Nitrate are shown in figure 1.4 below. Twelve samples of cube were immersed in solution of Magnesium sulphate plus natrium nitrate and another twelve samples of cube were immersed in water. The samples are to be immersed in the solution and water, separately for 7 days, 14 days, 21 days and 28 days. To get more accurate information on the effect of chemical reaction on the granite and limestone aggregate, test a period of 7 days, 14 days, 21 days and 28 days was justified. 12 Figure 1.4: Sample of chemical (Magnesium Sulphate + Natrium Nitrate) Figure 1.4 above show the chemicals to be used in the research. The chemicals are to be used in two different ways as the followings:- i) Half of the chemical to be used for the immersion of the concrete cube in the solution. ii) Another half of chemical to be used for the immersion of the granite and limestone aggregate in the solution. CHAPTER 2. LIETERATURE REVIEW 2.1 Introduction. Back to the problem about the specification in JKR project, there must be a reason why the limestone not to be recommended in concrete below ground level (Concrete Substructure). In obtaining to the matter a rise, there shall be some review about the aggregate in concrete structure and what is the weakness of limestone aggregate. This type of question is an objective of this study. Before we go further discussion, a few questions about the limestone aggregate are to be in mind as follows:- (a) What are the weaknesses and the results contribute to limestone concrete? (b) Is the chemical attack exists due to the use of limestone aggregate? (c) Corrosion will result crack in the concrete. Is the limestone the source of problem? (d) Can limestone concrete last long? 2.2 General Information of Aggregate. Firstly to answer that such question above, we have to get some general information regarding the use of aggregate in construction industrial technology in Malaysia. 14 Since three-quarters of volume of concrete is governed by aggregate, it is not surprising that its quality is of considerable importance. Not only may the aggregate affects the strength of the concrete, aggregate with undesirable material would not get a good and strong concrete but also its can produce low durability and performance of the concrete. Aggregate was originally a composition of a concrete mix with the proportion to the cement content and also as an inert material dispersed throughout the cement paste largely for economic purposes. It is possible to take into account that aggregate is a building material connected into a cohesive whole by means of the cement paste, as a comparison similar to masonry work in building construction. In fact, the aggregate can absorb heat, water, chemicals and also its physical properties will influence the performance of concrete. Aggregate cheaper compare to cement, there fore it is possible an economic value to put into consideration. But economy not the only reason why to select aggregate , it is also have engineering advantages on concrete, so that it can bring higher volume stability , produce better durability than the hydrated cement paste alone. 2.3 Particle shape and texture. Aggregate, whether crushed or naturally reduced in size, it can be divided into many groups of rocks having common characteristics. According to BS 812: Part 1: 1975 the rocks are classified as given in Table 1.0 in the early page. The aggregate to be used in the concrete shall have good shape and surface texture. In the case of crushed rocks, the particle shape depends not only on the nature of the parent material but on the type of crusher and its reduction ratio, for example the ratio of the size fed into crusher and the size of finished product. 15 According to standard BS 812: Part 1: 1975 is given from Table 1.2 in this chapter. For reference to the classification used in United States is as follows:Well-rounded - No original faces left Rounded - Faces almost gone Sub rounded - Considerable wear, faces reduce in area Sub angular - Some wear but faces untouched Angular - Little evidence of wear (* Page 113 Properties of concrete) Table 2.1: Particle Shape Classification of BS 812: Part 1: 1975 with examples Classification Rounded Description Examples Fully water-worn or completely shaped by River or seashore attrition gravel, desert, seashore and wind- blown sand Irregular Naturally irregular, or partly shaped by Other gravels, attrition and having rounded edges land or dug flint Laminated rock Flaky Material of which the thickness is small relative to the other two dimensions. Crushed rocks of all types , talus, Angular Possessing well-defined edges formed at crushed slag the intersection of roughly planar faces Elongated Material, usually angular, in which the length is considerably larger than the - other two dimensions Flaky and Material having the length considerably Elongated larger than the width, and the width considerably larger than the thickness (Note: The above table Refer to page 114 Properties of Concrete -A.M. Neville ) 16 As far as the aggregate concerned, the mass of flaky particles compare to a mass of sample isalled flakiness index where as for elongation index is similarly defined. For this case, particularly refer to JKR specification mention at the early page which means that the percentage of the flakiness and elongation should not more than 35% (Refer Appendix B). 2.4 Bond of the aggregate Bond between aggregate and cement paste is an important factor to produce a strength of concrete , therefore due to this reason a fully understood about the material properties is very significant. 2.5 Theory of Rocks. Everything should start with theory, so that it will bring more significant in studying towards analyzing purposes. Without the theory, an analysis meaning less to good results and better Due to this statement, a proper knowledge about the nature of rocks should be required in this research. The more the nature and the characteristics of the rocks required the more the analysis to be performed. In general, the Table 2.2 below shows the compressive strength of the original rocks for comparison to concrete cube strength. 17 Table 2.2: Compressive Strength of American Rocks Commonly Used as Concrete Aggregate. Compressive Strength Type of Number rock of After deletion of extremes ‡ Average# samples* MPa Psi Maximum MPa Psi Minimum MPa Psi Granite 278 181 26200 257 37300 114 16600 Felsite 12 324 47000 526 76300 120 17400 Trap 59 283 411000 377 54700 201 29200 Limestone 241 159 23000 241 34900 93 13500 Sandstone 79 131 19000 240 34800 44 6400 Marble 34 117 16900 244 35400 51 7400 Quartzite 26 252 36500 423 61300 124 18000 Gneiss 36 147 21300 235 34100 94 13600 Schist 31 170 24600 297 43100 91 13200 * For most sample, the compressive strength is an average of 3 to 15 specimens. # Average of all sample. ‡ 10 per cent of all samples tested with highest or lowest values have been deleted as not typical of the material Refer: A.M.Naville 1995 Page 121. 2.5.1 The Nature of Rocks Rocks are aggregate which is made of one or more minerals. Rocks are classified into three main types as follow:- a) Igneous rocks are formed from magma, which form below the surface, it ascends towards the surface, and crystallizes as solid rock on the surface of the earth. b) Sedimentary rocks are formed by the accumulation and compaction of 18 fragments from pre-existing rocks originated from the erosion of organic materials such as dead plants, animals and other dissolved material. Sedimentation rocks are also formed by the process of settlement and saturation of those particular organics or minerals. c) Metamorphic rocks are formed from pre-existing rocks, which undergo the increase in temperature or pressure or both. The original parent of the rocks change it’s appearance, texture and mineral composition due to the process stimulated. . 2.5.2 Igneous Rocks. In the formation of igneous rocks from magma, it is possible to describe three main types of classification in consideration of that particular rock as in the appropriate tables shown below:- Table 2.3: Minerals crystallization from magma. Mineral Ultra basic Basic Intermediate Acid Quartz ------------------------------------------------------ Orthoclase ------------------------------------------------------ Plagioclase Ca-rich ------------------------------------------------- Na-rich Muscovite -------------------------------------------------------- Biotite -------------------------------------------------------- Hornblende ------------------------------------------------------- Augite --------------------------- Olivine Early(high temperature) lately (low temperature) 19 Table 2.4: Minerals present in the four main groups of igneous rock. Rock Amount of composition SiO2(%) Acid 65 Minerals Quartz,orthoclase,Naplagioclase,muscovite, Biotite,(+/-hornblende) Intermediate 55-65 Plagioclase,biotite,hornblende,quartz, orthoclase (+/- augite) Basic 45-55 Ca-plagioclase,augite(+/-olivine,+/hornblende) Ultra basic 45 Ca-plagioclase,olivine(+/-augite) Magma consists of two distinctive layers, the bottom layer is the ultra basic igneous rocks which comprise divine, olivine, calcium-rich plagioclase and augite to form an ultra basic igneous rocks. This layer exists at high temperature. The second upper layer is the acids rock which comprises quartz, orthoclase, sodium-rich, plagioclase and micas. This second upper layer exists at a lower temperature. The layers are shown in table 2.4 above. 2.5.3 Sedimentation Rocks There are four major groups of sedimentary rocks:- a) Terrigenous sedimentary rocks that are formed by fragments derived from the breakdown of pre-existing rocks. b) Chemical sedimentary rocks that are formed through the precipitation of salts dissolved in water. c) Organic sedimentation rocks, which are formed from oil, coal and the skeletal remains of plants and animals. 20 d) Lime stones and dolomites, which are sedimentation, rocks consist of more than 50% carbonate including chemical, clastic and biological material. In this study, the rock which contains more carbonate is called carbonate rocks and limestone falls under this type of rocks. Therefore the fact of limestone is significant in this chapter to be further elaborated.. Figure 2.1: How sedimentation rock is formed For millions of years, little pieces of the earth have been eroded by wind and water. These little bits of the earth are washed downs by streams and eventually settle to the bottom of the rivers, lakes, and oceans. Layer after layer of the eroded earth is deposited on top of each other. These layers are pressed down more and more through time, until the bottom layers slowly turn into rock. (http://sln.fi.edu) 21 Figure 2.2: Limestone Rock (Sample 1) Limestone rocks are sedimentary rocks that are made of mineral calcite which comes from the beds of evaporated seas, lakes and sea animal shells. This rock is used in concrete and is an excellent building stone for humid regions. (http://sln.fi.edu). Figure 2.3: Limestone Rock (Sample 2) Limestone is the most abundant of the non-clastic sedimentary rocks. The main source of limestone is the limy ooze formed in the ocean. The calcium carbonate can be precipitated from the ocean water or it can be formed from the sea creatures that secrete lime such as algae and coral. Chalk is another form of limestone that is made up of very small single-celled organisms. Chalk is usually white or gray. Limestone can easily be dissolved by acids. If some vinegar is dropped onto a limestone, it will fizz. Put a limestone rock into a plastic jar and 22 cover it with vinegar. Cover the jar and watch the bubbling of the calcium carbonate and also the disintegration of the rock over a few days, (http://volcano.und.nodak.edu). 2.5.3.1 Carbonate Rocks. Limestone aggregate is one of carbonate rocks. Like other rocks, carbonate rocks are classified on the basis of their minerals and textures. The mineral compositions are limited and the textures of carbonate rocks are assumed of added importance. Some carbonate rocks are crystalline, and the others are clastic. Most rocks contain both crystalline and clastic elements. Limestone is composed predominantly of calcite, namely Magnesium calcite, aragonite and dolostones, dolostones consists primarily of dolomite, aragonite and dolostones are the two main types of carbonate rocks. Magnesium calcite and aragonite are particularly subject to diagenetic change and therefore calcite and dolomite are the most common phases in older carbonate rocks. Chemically, CaO, MgO and CO2 are lead carbonate rocks and the content of oxygen and carbon are significant in the analysis. 2.5.3.2 Limestone (Biochemical) Limestone is formed in various colour such as white, grey, cream or yellow. It’s texture is highly variable from very fine-grained, and porcellaneous, to coarsely crystalline and of sugary appearance. Its structure bedding is usually form the formation fossil layers. Usually limestone light is white or grey but can also be black if many impurities are present. It’s grain is typically fine, but it ranges from the microscopic to the size of a coral reef, which technically corresponds to one grain. 23 However, the formation of calcite or another carbonate can therefore be identified by dropping dilute hydrochloric acid onto its surface.The calcite rock releases carbon dioxide, and fizzes vigorously which indicates the presence of fossils. Theoretically, carbonate rocks consists of chemical sediments as shown below:- Table 2.5: Chemistry of selected carbonate rocks sediment. Si O2 K2O Ti O2 P 2 O5 Al2 O3 H 2 O+ Fe2O3 H 2 O- Fe O C O2 Mn O2 Ca CO3 Ca O Na 2 O Mg O LOl *Refer to Carbonate rock. Calcium carbonate normally comprises 50% of calcite, and the balanced are clay, sand, dolomite, carbon and iron oxides. In general, limestone is such as weathered rocks are crinoidal limestone, chalk, shelly limestone and fossiliferous fresh water limestone. Weathering often develops a thin white coating on pure limestone. Commonly the appearance of the limestone pebbles are grey and it is compact at the rock center and porous at the surface. Since limestone is formed in several ways and contains numerous impurities, many variations are found. This is includes shaly or argillaceous limestone, sandy or arenaceous limestone, lime conglomerate, bituminous limestone and glauconitic limestone. CHAPTER 3 RESEARCH METHODOLOGY 3.1 Introduction Since the scope and the objectives of the study has been obtained, there are a procedures should be followed to perform a specific function in this chapter. All the tests and the results shall be shown from appropriate table and graph that can be prepared simultaneously. At this stage, the main function is to show the various steps and methodology that lead to the results of testing materials selected. Once the characteristic of the materials selected has been tested through appropriate tests, the applicable standard of specification should be referred and the analyzed of the results should be done for better information as well as good conclusions. One of the objectives in this research is towards a better knowledge and good information to public that can make this study very significant. As a results this would brings the advantages to local people in promoting local material demands. 3.2 Experimental framework. In this research the methods to be carried out is through laboratory tests. The types of testing to be carried out are as follows:- 25 3.2.1 Sieve Analysis Test. 3.2.2 Flaky and Elongation Index Tests. 3.2.3 Cube Test 3.2.4 Aggregate Crushing Value Test. The sample of limestone aggregate was taken from quarry Poh Chan Sdn. Bhd located at Gunong Panas, Kg. Ulu Gali, Raub, Pahang. This sample was taken about one meter cube. The aggregate was divided into two volumes. One volume to make the concrete cubes in 24 numbers at ready mix kiln ( Poh Mix Sdn. Bhd.). These cubes were divided into two groups of specimen as the followings:- ( a ) 12 numbers of specimens fror immersions in chemical solution ( Magnesium Sulphate plus Natrium Nitrate) sample designated as : S1,S2,S3,S4,S5,S6,S7,S8,S9,S10,S11 and S12. ( b ) 12 numbers of specimens for immersions in water, 1,2,3,4,5,6,7,8,9,10,11 and 12. Figure 3.1 Preparation of Chemical Solution. designated as : 26 Figure 3.2 Immersion of cubes in to tank (chemical solution). Figure 3.1 and 3.2 above shows the preparation of cube to be immersed into the chemical solution for 7 days, 14 days, 21 days and 28 days. Another one volume of limestone aggregate was divided into two portions as the followings:( i) 20 kilograms for immersion in chemical solution ( Magnesium Sulphate plus Natrium Nitrate) ( ii ) 20 kilograms for immersion in water. The aggregates were taken out from curing tank after 7 days and 28 days for sieve analysis test, flaky/elongation test and aggregate crushing value test. The tests were carried out in UTM Skudai Highway Laboratory in January 2005. 27 Whereas for concrete cubes, the samples were taken out after 7 days, 14 days, 21 days and 28 days for cube tests at Poh Chan Sdn. Bhd. Plant. The date of testing as shown in Table 3.1 below:Table 3.1 Date of Cube Test. 3.3 No. of days Date of testing 7 9.12.2004 14 16.12.2004 21 23.12.2004 28 30.12.2004 Experimental Details. Since the study of aggregate is more important, it is not really truth accept by the method of testing should be carried out to that particular material. For this purpose, before material has to be tested, one consideration should be noticed where the raw material is located and where the materials to be used in particular project. In this research, the raw material to be tested is from Gunong Panas, Kg. Ulu Gali, Raub, Pahang. This raw material is commonly used as limestone aggregate in Raub district and very popular to the local people as the main source of local material demands. Figure 3.1 and 3.2 below shows where the location and the site of the raw material was been taken for the specimen. 28 Figure 3.3(a): Front view of Gunong Panas, Ulu Gali, Raub. Figure 3.3(b) Side View Of Gunong Panas, Kg. Ulu Gali, Raub. 29 3.3.1 JKR Standard Specification for Aggregate The most important thing in this chapter is to describe an appropriate methods how to initiate and solving procedure in respect to the back ground situation and problem arise. Since the research is subjected to the effect of limestone aggregate in concrete structure below ground level, it is more significant the material should accordance to the standard JKR specification. Therefore, the following paragraphs are the procedures and the standard specification for building work prepared by JKR. 3.3.1.1 General Aggregate The aggregate to be used in the concrete should comply to standard specification mentioned below:The aggregate shall in general comply with M.S 7.5. All aggregate shall be hard, strong, durable, clean and free from adherent coating and shall not contain harmful materials in sufficient quantity to affect adversely the strength or durability of the concrete or to attack the reinforcement. Aggregate shall be store in such a manner as to prevent contamination by undesirable substance. The different type of aggregates shall be stored in separate bins and not be allow to intermingle. (Refer to Appendix A1). 30 Figure 3.4: The sieve analysis apparatus. Figure 3.4: Method of testing the aggregate in the UTM Highway laboratory on January 2005. 3.3.1.2 Fine Aggregate The fine aggregates shall be naturally occurring fresh water sand. The aggregates shall not contain silt or other fine materials exceeding 3% by volume when tested according the Standard Method given in M.S 7.5. Neither shall it contain organic material in sufficient quantity to show a darker colour then the standard depth of colour No. 3 when tested according to the method in M.S 7.5. The use of crushed stone sand shall not be permitted.(Refer to appendix A1). 31 3.3.1.3 Coarse Aggregate The course aggregate shall be crushed hard stone except that for work below ground level, only crushed granite will be used. The aggregates shall not contain clay lumps exceeding 1% by weight. A representative dry sample shall not show an increase in weight exceeding 8% after immersion in water when tested according to the method in MS. 7.5. It shall be well shaped and not flaky with the flakiness index not exceeding 35. The maximum nominal size of coarse aggregate shall be 19mm. (Refer to Appendix A1). Figure 3.5: Sample of Limestone and granite aggregate in UTM Highway Laboratory. 3.3.2 Aggregate Grading The analysis for the grading of aggregate shall be as described in MS. 7.5 and shall be within the limits specified as Table 3.2 and 3.3 below:- 32 Table 3.2: Fine Aggregate (Natural sand) B.S. Sieve 5mm % Passing 95-100 2.36mm 70-95 1.18mm 0.60mm 45-85 25-60 0.30mm 0.15mm 5-30 0-10 Table 3.3: Coarse Aggregate (Nominal size 20mm). B.S. Sieve 20mm 10mm 5mm % Passing 100 25-55 0-10 The grading between the limits specified above shall be to the approval of the S.O., and when tested as provided herein after shall approximate closely to the grading of the approved samples. If it should be found necessary, the fine aggregate shall be washed and/or screened to comply with and the requirements of the S.O. (Refer Appendix A2 under clause 3.4) 3.3.2.1 Sampling and Testing of Aggregates The method of sampling and the amount of aggregate to be provided for the tests shall be in accordance with section 2 to 6 of MS. 7.5. Samples of the fine and coarse aggregate approved by the S.O. shall be kept on site and shall be used to compare the general quality of the aggregates delivered during the course of the work. The tests to be performed on the aggregates shall be as specified herein before. The S.O. may require further tests to be carried out on samples of the aggregate delivered to site at intervals. The tests shall be carried out by the S.O. or his representative. Should a sample fail to comply with any of the tests the S.O., may, at his discretion, either reject the batch from which the sample was taken, order it to be washed and or screened or permit it to be used with variation in the proportions of the concrete mixes specified. Any batch of aggregate rejected by the S.O. shall be removed from the works site forthwith. 33 3.3.2.2 Storage of Aggregates Separate storage facilities with adequate provision for drainage shall be provided for each different size of aggregate used. Aggregate shall be handled and stored so as to minimize segregation and contamination. 3.4 Water Water shall comply with the requirements of M.S. 28. It shall be clean and free from materials deleterious to concrete in the plastic and hardened state and shall be from a source approved by the S.O. If in doubt, the S.O. may instruct the contractor to carry out chemical test at any approved laboratory at the expense of the contractor. The contractor shall make adequate arrangement to supply and store sufficient water at the work site for use in mixing and curing of concrete. All costs for installing and maintaining the supply shall be borne by the contractor. 3.5 Types of Test Recommended The test to be carried out in the laboratory at University Technology Malaysia, Skudai, Johor are represents as follows:- (i) Sieve Analysis Test ( ii ) Elongation ( iii ) Flakiness Index ( iv ) Concrete Cube Test (v) Aggregate Crushing Value 34 In conjunction to the tests, it is important to notice that every steps of the procedure in making the appropriate tests should be identified and followed to get an accurate result. Every procedure in the tests should be strictly followed for getting a good results and this can be explained each of the tests in the following paragraphs. 3.5.1 Sieve Analysis Test Before the aggregate to be tested for sieve analysis, the sample of aggregate has to be taken from the source of the materials. In this case, the sample of aggregate is taken from the quarry Po Chan situated at Gunong Panas,Kg. Ulu Gali, Raub, Pahang as shown in the Figure 3.6 below:- Figure 3.6: Site view of Gunong Panas, Kg.Ulu Gali,Raub, Pahang 35 The sample of aggregate was taken from Gunong Panas area as shown from figure 3.6 above. The test was carried out at UTM Highway laboratory on January 2005. The procedure to carry out Sieve analysis test:- 3.5.1.1 Sample of Aggregate to be tested. Take the sample of limestone aggregate of 4 kilogram as shown in Figure 3.7 below:- Figure 3.7: Sample of limestone aggregate for Sieve Analysis Test. The sample of limestone then placed into the apparatus for sieve analysis test as shown in Figure 3.8 below:- 36 Figure 3.8: Apparatus in Analysis Test. The aggregate analysis should according to JKR specification and passing through the sieve as Table 3.4 below:- Table 3.4: Position of Sieve size Layer of sieve Sieve Size.( mm ) Top 37.5 Third 20.0 Second 10.0 First 5.0 The limestone aggregate shall be sieved until an appropriate time that the aggregate pass through each sieve size and weight the balance on each sieve for calculation and record purposes. The results of this test will be written under next chapter which is on the Results and Analysis section. 37 3.5.1.2 Elongation and Flakiness Index Test. Elongation is the test which is aggregate particles can pass through the plate consist of longitudinal hole whereas flakiness index is the aggregate particles can pass through the standard hole from the steel plate apparatus as shown from Figure 3.9 below:- Figure 3.9: Apparatus for Elongation and Flakiness Index Test (Steel plate With Standard Hole) The procedure for elongation and flakiness index test are the followings:- Once the sieve analysis test completed, the aggregate will be taken into elongation test. The aggregate sample which is retained on sieve of 14mm, 10 mm and 6.3 mm in size is to be tested by passing through the slot from the hole of the steel plate apparatus as shown from the Figure 3.9 above. By this method, the amount of aggregate passing through the slot will be taken and take the weight of the aggregate, compare to the total weight of aggregate retained. Method of testing elongation and flakiness index is by taken the weight of aggregate passing through the slot of steel plate. The results should be recorded using the format in table 3.5 below:- 38 Table 3.5: Standard Format for Calculation of Elongation and Flakiness Test. Aggregate Aggregate Aggregate Aggregate Sieve size Weight retained Passing Passing (mm) on sieve Elongation Slot Flakiness Slot ( gm ) (gm ) ( gm ) 14 A1 B1 C1 10 A2 B2 C2 6.3 A3 B3 C3 5.0 A4 B4 C4 Total Weight (A1+A2+A3+A4) (B1+B2+B3+B4) (C1+C2+C3+C4) =A =B =C After Sieve Analysis Test completed. Weight and record all the samples retained on the sieve as in the table 3.5 above. Take the Value of A, B and C 39 Calculate the percentage passing on the slot. Use formula, Elongation = B/A X 100% Flakiness = C/A X 100% as shown in table 3.5 above Compare and analyzed the results to JKR Specification End Figure 3.10: Procedure for Elongation and Flakiness Index Test. 3.5.2 Concrete Cube Tests. For concrete cube strength, the tests was done at the kiln which is situated at factory of Pohmix Sdn. Bhd., Lipis Road, Raub, Pahang. Before concrete cube to be tested, the mixed was to be prepared and immersion into the ordinary water and chemical soluble Of Magnesium Sulphate plus Natrium Nitrate for a period of 7, 14, 21 and 28 days. The process of immersion the cube into chemical solution was very important because the actual strength can be compared simultaneously for an analysis purposes. For the purpose of the test, there were twenty four (24) numbers of cubes to be prepared and placed into the water and chemical solution. The sample of chemical Magnesium Sulphate plus Natrium Nitrate was shown 40 from the Figure 1.4 under Chapter 1 at the previous paragraph. For a practical knowledge and information purposes, the sample of Magnesium Sulphate and Natrium Nitrate was in the form of small particles and looks like the salt which is in white colour. 3.5.2.1 Preparation of Concrete Cube 150x150x150 Grade 25 Before concrete cube to be ready, the limestone aggregate was taken from Quarry at Gunong Panas to the Pohmix Sdn. Bhd. Kiln. The concrete cube was prepared for the numbers of twenty four(24) using machine mixed (Computer Operated). The mixed of concrete used was for grade 25 which is according to the JKR specification as per listed below:- Table 3.6 The mix proportion of Concrete cube Grade 25. Water Cement Ratio = 0.5 Proportion of Concrete Cube by Volume Proportion by weight per 1m3 concrete Cement =1 361 kg. Fine Aggregate =1½ 525 kg Coarse Aggregate =3 1225 kg. The preparation of the concrete cube was carried out by the supervisor of Pohmix Sdn Bhd. and his assistant as shown from the Figure 3.10 below:- 41 Figure 3.11 Preparation of Concrete Cube. The procedure for the preparation of concrete cube should be followed according to the general procedure as mentioned in Figure 3.13 below:- During the placing of concrete into the mould, there are a standard procedure for the compaction of the concrete. The concrete to be poured into the mould shall be in separate time with three layers compaction and each layers need 35 strokes by steel 25x25 square pattern. The methods of compaction the concrete in the mould as shown through the Figure 3.12 below:- 150 Layer 3(35 stroke) Layer 2(35 stroke) 150 Layer 1(35 stroke) Concrete in Mould Steel Rammer Compacted in Three Layers. 25 x 25 square. Figure 3.12: Procedure in Preparation of cube. 42 Prepare the concrete mix( Gred 25 ) Test Slump Figure 3.14 Once the mix ready, Prepare takeConcrete out the sample Cube. and take the Slump as shown from Figure Picture3.15 3.9 below. Marked The Cube: In Solution S1,S2,S3,S4,S5,S6,S7,S8,S9,S10,S11,S12 Figure 3.13: Step to prepare 150x150x150 Concrete Cube. 43 Figure 3.14 Measuring the Slump of Fresh Concrete. Figure 3.15 Preparing the Concrete Cubes. 44 Table 3.7 Date of Casting and Testing of Concrete Cube Date of casting: Date of testing 02 December Sample No. in Sample No. in the soluble. the normal water(JBA) 2004/ No. of days 7 09 December S1, S2 & S3 1, 2 & 3 S4, S5 & S6 4, 5, & 6 S7, S8 & S9 7, 8 & 9 S10,S11 & S12 10,11 & 12 2004 14 16 December 2004 21 23 December 2004 28 30 December 2004 The procedures carried out the cubes test are the following:1. Take out the sample from the tank and weighted the cube as shown in Figure 3.16 below:- Figure 3.16: Weighting the cube sample 45 2. Put the cube under the plunger and test under compression as shown in Figure 3.17 below:- Figure 3.17: Testing of Cube. 3. Read the compressive strength through dial gauge as shown in Figure 3.18 below:- Figure 3.18: Record Compressive Strength from dial gauge. 46 4. Take out the cube sample from Testing machine and see the failure pattern as figure 3.19 below:- . Figure 3.19 Failure Pattern Of Cube. 5. End of the test. Figure 3.20: End of the test. 3.5.3 Aggregate Crushing Value Test. Since concrete is formed mostly by the aggregate, therefore the crushing strength of the material should be determined for acknowledgement. 47 Before the limestone aggregate to be tested for crushing value, the sample firstly has to be immersed in normal water and solution of Magnesium sulphate plus Natrium nitrate for comparison purposes. 3.5.3.1 Preparation of Limestone aggregate for crushing value test. The sample of limestone selected, however for the purpose of the study the materials need to immerse in the water and soluble Magnesium sulphate plus Natrium Nitrate. In reality the concrete below ground level is subjected to reaction of sulphate, chloride, Nitrate and others chemical agent. At the beginning of this case study, the selected limestone aggregate was taken from the source( Quarry Poh Chan, Kg. Ulu Gali, Raub) and on Fifth December 2004 was been immersed in the water and in the soluble of Magnesium sulphate plus Natrium Nitrate. The amount of the aggregate and the volume of soluble required as per table 3.8 below:- 48 Table 3.8: Quantity of Aggregate /Mg SO4 + Na NO3 and Water Content. Amount of Volume of Volume of Duration of Limestone water required soluble aggregate in /Granite ( liter ) Magnesium the water/in the Aggregate sulphate + chemical selected Natrium solution. ( Kg ) Nitrate. ( Days ) (Liter/Kg) 5 (Limestone) 10 20 7 5 (Limestone) 10 20 28 5 (Limestone) 10 - 7 5 (Limestone) 10 - 28 5( Granite ) 10 - 28 5 ( Granite ) 10 20 28 On the selection of limestone and granite aggregate for the immersion into the water with the soluble of Magnesium sulphate plus Nitium Nitrate, the process was began on the Fifth December 2004 and the testing will be carried out at UTM laboratory, Skudai, Johor Bahru. Aggregates are allowable to be tested on the laboratory, the dates for taken out from immersion tank should be calculated and the dates required are according to table 3.9 below:- 49 Table 3.9 Date of Immersion and Taken out of an Aggregate. Date of Immersion into Numbers of Immersion Date of Aggregate to be Normal water(JBA) Period ( Days ) taken out. and Solution Mg SO4 + ( Limestone/Granite) Na NO3 ( solution/non solution) / No of sample Limestone aggregate Fifth December 2004 7 12 December 2004 ( A1 ) ( A2 ) ( Non soluble ) 7 12 December 2004 ( With soluble ) ( A3 ) 28 2 January 2005 ( Non soluble ) ( A4 ) 28 2 January 2005 ( With soluble ) Granite aggregate ( A5 ) 28 2 January 2005 ( Non soluble ) ( A6 ) 28 2 January 2005 ( With soluble ) In this chapter the methods of the test involved to the limitation time of 28 days only and the results will be obtained after the test has been done in the laboratory UTM Skudai. For this purpose the detailed explanation will be appeared in next chapter under the results and analyzed topic. 50 For the purpose of this chapter, the procedure required in the ACV tests will be showed through Figure 3.21 until 3.26 below:- Weighting of aggregate(4 Kg.) Figure 3.21 below:- Figuge 3.21 Weighting of Limestone Aggregate for ACV test. 51 Put the aggregate in to the mould until full. (Figure 3.22) Figure 3.22: Placing Aggregate in to the mould. Put the mould under Plunger and testing. (Figure 3.23) Figure 3.23: Aggregate under testing (400kN/10 minutes) 52 Set time for 10 minutes until load reach 400 kN reading from Dial gauge. (Figure 3.24) Figure 3.24: Aggregate under rate of crushing 40kn/minutes. After 10 minutes with 400 kN reading on dial gauge, take out the sample, weighted. (Figure 3.25) Take value as ‘ A’. Figure 3.25: Sample of aggregate after crushing. 53 Sieve the sample on 2.36 mm sieve size, take the retain sample and weight. (Figure 3.26) Take value as ‘B’. Figure 3.26: Crushed sample of aggregate retain on 2.36mm sieve. Calculate ACV = B/A X 100 END Figure 3.26 above shows end result of the ACV test. The amount of aggregate crushed divided to total weight of aggregate sample (Figure 3.25) time by 100% is called Aggregate Crushing Value. Detail results will be shown under next chapter. CHAPTER 4 RESULTS AND ANALYSIS 4.1 Introduction. In this chapter, the most important thing is the analysis of the results due to the back ground problems. However, for this particular topic the record of the test should be the first priority to be considered in predicting any theory towards the actual condition on site before conclusion can be made. 4.2 The results of Sieve Analysis. The specimen of the aggregate has been sieved in the laboratory of UTM Skudai in January 2005. Before further discussion it is possible to look into the analysis in which the fact and figure can be traced. For that reason the results of the tests should be properly arranged for better understanding of the problem. Here are the results of the test to be discussed and analyzed as in the table 4.1 below:- 55 Table 4.1 Results of Sieve Analysis of Limestone Aggregate. Sieve Size Weight Weight Percent Percent ( mm ) retain on passing retain Passing Sieve ( gm ) (%) (%) ( gm) 37.5 - - - - 28.0 - - - - 20.0 15.1 3966.3 0.37 99.63 14.0 1480.6 2485.7 37.2 62.43 10.0 1451.3 1034.4 36.45 25.98 6.3 990.6 43.8 24.88 1.10 5.0 43.8 0.0 1.10 0.0 Total 3981.4 gm 100.00% 56 Graph % Passing VS Sieve Size 120 % Passing 100 80 Max passing Min passing Actual passing 60 40 20 0 5 6.3 10 14 20 28 Sieve Size Figure 4.1: Graph of Sieve analysis test for Limestone aggregate Since the sieve analysis resulted to size of aggregate comparing to the JKR standard specification (Section D – concrete work clause 3.40, the elongation and flakiness index directly can be measured and the results of the test are listed in the Table 4.2 below: 57 Table 4.2: Results of the Elongation and Flakiness index of Limestone aggregate. Sieve Size (mm) Weight retain Passing Slot Passing Slot ( gm ) Elongation Flakiness ( gm ) ( gm ) 37.5 - - 28.0 - - 20.0 15.1 - - 14.0 1480.6 271.5 205.1 10.0 1451.3 313.0 378.2 6.3 990.6 143.0 200.7 5.0 43.8 - - TOTAL 3981.4 727.50 784.00 The Calculations for Elongation and Flakiness Index are as follow: Elongation = 727.5/3981.4 X 100 = 18.27% < 30% (JKR) , Pass. Flakiness Index = 784.00/3981.4 X 100 = 19.7% < 35% (JKR), Pass Graph Relationship Between Elongation/Flakiness Index and JKR Standard 35 35 30 30 Elongation Index 25 Elongation (JKR Standard) 20 18 % Limits 19.7 Flakiness Index 15 Flekiness Index (JKR Standard) 10 5 0 Elongation/Flakiness Index 1 and JKR Standard Figure 4.2: Relationship between Elongation/Flakiness Index and JKR Standard 58 4.2.1 Analysis of Sieve analysis results. Before further discussion on the results, comparison to the JKR specification should firstly be considered. With reference to the Table 4.1 and Figure 4.1 for the last paragraph, it shows that the percent passing of limestone aggregate (red line) is in the region of the standard JKR specification. Through this testing it shows that the limestone aggregate complies to the JKR standard specification. For reference purposes, below is a comparison table showing the values recorded through the test. Table 4.3 Comparison of Aggregate Passing to JKR specification. Sieve Size (mm) % Passing of aggregate % Passing of from JKR specification. Limestone aggregate sample. 20 100 99.63 10 25 – 55 25.98 5 0 – 10 0 From the Table 4.3 it shows that the percent of limestone aggregate passing through the standard sieve size are 99.63%, 25.98% and 0% which is in the range of the JKR specification. 4.2.2 Analysis of Elongation and Flakiness Index Test Results. From the result of the tests showed that the values of elongation and flakiness index are below the limit of JKR standard specification. With that values of index, it will reflects to positive answer and make this study very significant. 59 The advantages of this study are very important to predict and discussed further about the use of limestone since the texture and the shape of the aggregate on the acceptance condition. Due to this study, some justification is applicable to be an acknowledgement to public especially for local people. From the analysis, some assumption can be predictable since the aggregate was very useful to the local benefit. The factors make the aggregate acceptable are as follows:- ( i ) The main factor to produce a good crushed aggregate is the operation of the quarry which is very important role in every aspect of quality control as well as machinery and skill operators. ( ii ) The condition of rock at that place whether the chemical existence mixed more than the required limit compare to rock origin. ( iii ) Psychology effect due to the alternative aggregate such as granite. ( iv ) The knowledge about the aggregate properties should be very useful especially to the designers and Engineers which is responsible in preparing the specification. ( v ) Cost incurred is the most important part on the demands of the material without prejudice. 4.3 The Results of Concrete Cubes Strength. Strength is the most important factor to be considered in concrete structural purposes. This is because of the technical and engineering theory about the structure in respect to strength and durability. Durability and strength are two different things in concrete structure, however the higher the strength the better the concrete but it does not guaranteed for long lasting as well as high 60 performance as required. The results of the cube test for limestone concrete are shown in Table 4.4. Table 4.4 The Results of Cubes Test. Date of Date of Cube Strength in Cube Strength in casting/ Testing / solution : normal water curing No. of No of Mg SO4+Na (N/mm2) days Sample NO3(N/mm2) 02.12.2004 09.12.2004 7 02.12.2004 14 02.12.2004 21 02.12.2004 28 Average Average S1 26.6 23.50 S2 25.7 S3 26.2 23.20 S4 29.7 26.6 S5 29.3 S6 29.5 27.7 S7 34.2 29.7 S8 31.5 S9 34.6 30.4 S10 31.1 33.5 S11 35.3 S12 32.8 26.16 22.60 23.10 16.12.2004 29.5 26.2 26.8 23.12.2004 33.4 31.5 30.5 30.12.2004 33.06 33.5 33.3 33.40 61 Limestone cube strength compared to JKR Standard 7 days in solution. 30 26.6 25.7 26.2 25 Compressive 20 15 Strength (N/mm2) 10 17 SPECIMEN S1 SPECIMEN S2 SPECIMEN S3 5 JKR STANDARD 0 1 JKR Specimen and Standard Figure 4.3: Limestone concrete cube strength in chemical solution for 7 days. Limestone cube strength compared to JKR standard 7 days in water. 25 20 23.5 22.6 23.2 17 Compressive 15 Strength (N/mm2) 10 SPECIMEN 1 SPECIMEN 2 SPECIMEN 3 5 JKR STANDARD 0 1 Standard Specimen and JKR Figure 4.4: Limestone Concrete Cube Strength in Water for 7 days. 62 Cube strength of limestone concrete compared to JKR standard 28 days in solution. 40 35 30 Compressive 25 Strength 20 (N/mm2) 15 10 5 0 35.3 31.1 32.8 25.5 SPECIMEN S10 SPECIMEN S11 SPECIMEN S12 JKR STANDARD 1 Standard Specimen and JKR Figure 4.5: Limestone concrete cube strength in chemical solution for 28 days. Cube strength of limestone concrete compared to JKR standard 28 days in water. 35 30 33.5 33.6 33.3 25.5 25 Compressive 20 Strength 15 (N/mm2) 10 SPECIMEN 10 SPECIMEN 11 SPECIMEN 12 JKR STANDARD 5 0 1 Standard Specimen and JKR Figure 4.6: Limestone Concrete Cube Strength in water for 28 days. 63 4.3.1 Analysis from the Results. The tests which has been done separately as mentioned in the above table 4.4 was taken at the factory of Poh Mix Sdn. Bhd.,Lipis Road,Raub, Pahang. From the results obtained, we can analyzed and discuss about the concrete strength as well as quality of the concrete. 4.3.1.1 Analysis in respect to strength. To analyze and discuss about the strength of the concrete, it is better in the formed of questionnaire to get clear understanding and better information. To begin that lets start with first question regarding the strength of the concrete. ( 1 ) Why is so important the cube strength of the concrete during the construction? The answer of this question will reflects to this study and related to the back ground problem from the JKR specification. There are various reasons and also many factors contribute to the strength of the concrete structure. Through this case study, the element concerned in concrete is the use of limestone aggregate in concrete structure. Through this study, a few advantages can be found especially related to quality of the concrete. In respect to the first question above, it is possible to relate this with JKR specification from table 1.4 (Chapter 1) and also table 2.2 (Chapter 2) compressive strength of American rocks in the first and second chapter under previous paragraph. To have a clear picture and better explanation about the results and analyzed purposes the table 4.5 below is very appropriate to the answer. 64 Table 4.5 The Result of Cube Strength Compare to JKR Specification. No of Characteristic Average Strength Average Strength days Strength from JKR from sample from sample specification specimen in normal specimen in ( N/mm2 ) water. soluble Mg SO4 + ( N/mm2 ) Na NO3 ( N/mm2 ) 7 17.0 23.10 26.16 28 25.5 33.40 33.06 Average Cube Strength 7 days. Average Cube Strength for 7for days. Compressive Strength (N/mm2) 30 26.16 25 20 23.1 STRENGTH IN WATER 17 STRENGTH IN SOLUTION 15 JKR STANDARD 10 5 0 1 Specimen and JKR Standard Figure 4.7: Limestone Concrete Cubes Strength Compared to JKR Standard for 7 days (Average Strength) 65 Average Strength of Concrete Cube in 28 days. Compressive Strength (N/mm2) 40 35 30 33.06 33.4 25.5 25 SPECIMEN IN SOLUTION SPECIMEN IN WATER 20 15 JKR STANDARD 10 5 0 1 Specimen and JKR Standard Figure 4.8: Limestone Concrete Cube Strength Compared to JKR Standard for 28 days (Average Strength) ( 2 ) What can we say on the above figure? Figure 4.8 conformances to specification. Everything done on the construction area, the first priority to be in the mind of Engineers as well as supervisors is to make sure that the work is follows the specification bound in the contract. This statement is the answer to the first question. For the second question, the answer will be discussed below:- ( a ) Strength of Concrete Cube in Normal Water. The values in Table 4.5 are summarized below:Cube Strength of Specimen for 7 days = 23.10 > 17.0 (JKR Spec), Satisfied Cube Strength of Specimen for 28 days = 33.40 > 25.5 (JKR Spec), Satisfied. Since the concrete cubes comply to the specification for 7 days and 28 days duration, one case study was conducted by researchers as mentioned in the 66 Table 2.2 under Chapter 2 last paragraph. This is the study about the compressive strength of the American rock which is commonly used for crushed aggregate in concrete structure. For comparison purposes, this is a significant answer and one of the criteria to be considered in selecting the aggregate for concrete structure. To elaborate the compressive strength of the rock, it is relevant to compare the result and the cube strengths for record purposes. The comparison is tabulated below:- Table 4.6: Comparison of Compressive Strength of Rock to Concrete Cube. Compressive Strength Compressive Strength Compressive Strength of Limestone Rock of Granite Rock. of Concrete Cube ( N/mm2 ) ( N/mm2 ) Specimen ( N/mm2 ) 159.00 181.00 33.06 67 Compressive strength in concrete cube as compared to the compressive strength in original rock 33.06 159 Limestone Rock Granite Rock 181 Limestone concrete cube 1 2 3 Figure 4.9: Relationship between Concrete cube Compressive Strength to Original Rock. 4.4 The Results of Aggregate Crushing Value (ACV) Test. In the Aggregate Crushing Value(ACV) Test, the limestone and granite aggregate, which were tested from 5 January to 6 January 2005 at Highway Laboratory UTM Skudai, Johor Bahru. The results of test were properly recorded in the following tables:- 4.4.1 Test 1 on the 5 January 2005: Sample of Limestone Immersion in Soluble Mg SO4 + Na NO3 for 7 days. Total weight of Sample Aggregate in Sieve Analysis test = 4000 gram. Total Weight of sample Aggregate retain on 14- 10 sieve = 2931.9 gram 68 Table 4.7 Data Record of ACV Test 1(14-10 sieve) Sieve size ( mm ) Weight retain before Weight ACV test ( gram ) Passing/retain after ACV test ( gram ) Passing 37.5 - 28.0 - 20.0 15.1 14.0 1480.6 10.0 1451.3 6.3 990.6 5.0 43.8 2.36 - 807.3 3981.4 2779.00 Total = Total Weight of Aggregate after ACV test Retain 1,971.70 = 2779.00 gram. Total weight of aggregate Passing in 2.36 sieve = 807.30 gram. Therefore, ACV = 807.30/2779 X 100% = 29.00% Standard JKR Specification for ACV Test = Not Exceeding 40% (Table 3 page 30 Specification for Structural Concrete.) – Refer appendix B Therefore, ACV = 29% < 40%, consider satisfied. 4.4.2 Test 2 carried out on the 5 January 2005: Sample of Limestone Immersion in Soluble Mg SO4 + Na NO3 for 28 days. Total weight of Sample Aggregate in Sieve Analysis test = 4000 gram. Total Weight of Sample Aggregate retain14- 10 sieve = 2955.84 gram 69 Table 4.8: Data Record of ACV Test2 (14-10 sieve). Sieve size ( mm ) Weight retain before Weight ACV test ( gram ) Passing/retain after ACV test ( gram ) Passing 37.5 - 28.0 - 20.0 13.97 14.0 1557.30 10.0 1398.54 6.3 978.57 5.0 45.90 2.36 - 898.10 3,994.28 Total Weight of Aggregate after ACV test Retain 1,976.80 2,874.90 = 2874.90 gram. Total weight of aggregate passing in 2.36 sieve = 898.10 gram. Therefore, ACV = 898.10/2874.90 X 100% Standard JKR Specification for ACV Test = 31.24% = Not Exceeding 40% (Table 3 page 30 Specification for Structural Concrete.) – Refer Appendix B Therefore, ACV = 31.24% < 40%, consider satisfied. 4.4.3 Test 3 on the 6 January 2005 : Sample of Limestone in water for 7 days. Total weight of Sample Aggregate in Sieve Analysis test = 4000 gram. Total Weight of sample Aggregate ratain20- 14 sieve = 2,806.90 gram 70 Table 4.9 Data Record of ACV Test3 (20-14 sieve) Sieve size ( mm ) Weight retain before Weight ACV test ( gram ) Passing/retain after ACV test ( gram ) Passing 37.5 - 28.0 - 20.0 568.00 14.0 2238.90 10.0 909.72 6.3 213.87 5.0 60.21 3.35 - - 823.90 3,990.70 Total Weight of Aggregate after ACV test Retain 1,942.00 2,765.90 = 2,765.90 gram. Total weight of aggregate passing in 3.35 sieve = 823.90 gram. Therefore, ACV = 823.90/2765.90 X 100% Standard JKR Specification for ACV Test = 29.80% = Not Exceeding 40% (Table 3 page 30 Specification for Structural Concrete.) – Refer Appendix B Therefore, ACV = 29.80% < 40%, consider satisfied. 4.4.4 Test 4 on the 6 January 2005: Results Limestone in water (28 day) Total weight of Sample Aggregate in Sieve Analysis test = 4000 gram. Total weight of sample Aggregate retain 20- 14 sieve = 2,840.50 gram 71 Table 4.10 Data Record of ACV Test3 (20-14 sieve) Sieve size ( mm ) Weight retain before Weight ACV test ( gram ) Passing/retain after ACV test ( gram ) Passing 37.5 - 28.0 - 20.0 508.20 14.0 2332.30 10.0 298.00 6.3 807.08 5.0 13.02 3.35 - - 716.50 3,958.60 Total Weight of Aggregate after ACV test Retain 1,890.70 2,607.20 = 2607.20 gram. Total weight of aggregate passing in 3.35 sieve = 716.50gram. Therefore, ACV = 716.50/2607.20 X 100% Standard JKR Specification for ACV Test = 27.48% = Not Exceeding 40% (Table 3 page 30 Specification for Structural Concrete.) – Refer Appendix B Therefore, ACV = 27.48% < 40%,(satisfied). 4.4.5 Test 5 on the 6 January 2005 : Results of Granite in chemical solution Mg SO4 + Na NO3 (28 day). Total weight of Sample Aggregate in Sieve Analysis test 4000 gram. Total weight of sample Aggregate retain 14-10 sieve = 3010.30 gram 72 Table 4.11 Data Record of ACV Test5 (14-10 sieve) Sieve size ( mm ) Weight retain before Weight ACV test ( gram ) passing/Retain after ACV test ( gram ) Passing 37.5 - 28.0 - 20.0 40.20 14.0 1600.40 10.0 1409.90 6.3 890.85 5.0 56.35 2.36 - - 588.50 3,997.70 Total Weight of Aggregate after ACV test Retain 2,410.40 2,998.90 = 2,998.90 gram. Total weight of aggregate passing in 2.36 sieve = 588.50 gram. Therefore, ACV = 588.50/2998.90 X 100% Standard JKR Specification for ACV Test = 19.62% = Not Exceeding 40% ( Table 3 page 30 Specification for Structural Concrete.) – Refer Appendix B Therefore, ACV = 19.62%< 40%, (satisfied). 4.4.6 Test 6 on the Six January 2005: Results of Granite in water ( 28 day). Total weight of Sample Aggregate in Sieve Analysis test = 4000 gram. Total Weight of sample Aggregate retain 20-14 sieve = 3005.10 gram 73 Table 4.12 Data of ACV Test 6 (20-14 sieve) Sieve size ( mm ) Weight retain before Weight ACV test ( gram ) passing/Retain after ACV test ( gram ) Passing 37.5 - 28.0 - 20.0 1224.70 14.0 1780.40 10.0 500.90 6.3 450.73 5.0 36.47 3.35 - - 550.80 3,993.20 Total Weight of Aggregate after ACV test Retain 2,438.40 2,989.20 = 2,989.20 gram. Total weight of aggregate passing in 2.36 sieve = 550.80 gram. Therefore, ACV = 550.80/2989.20 X 100% Standard JKR Specification for ACV Test = 18.43% = Not Exceeding 40% ( Table 3 page 30 Specification for Structural Concrete.) – Refer Appendix B Therefore, ACV = 18.43%< 40%, (satisfied). 4.5 Analyzing the results of the Aggregate Crushing Value (ACV) Test. All 6 test results tabulated in test 1, test 2, test 3, test 4, test 5 and test 6 are as per the digits obtained accurate and the numbers elaborate the strength of the aggregate required. Figure 4.10, 4.11 and 4.12 below are the above test results in bar chart format. Figure 4.10 showing the results of Aggregate Crushing Value Test for 7 days of limestone aggregate in chemical solution and water. 74 Crushing values ofvalues limestone aggregate compared to Crushing of limestone aggregate JKR Standard for 7 days. compared to JKR Standard for 7 days. 40 40 35 29 29.8 30 25 Percentage 20 Crushing(%) 15 10 5 0 1 Specimen and JKR Specification Limestone in Solution Limestone in water JKR Standard Figure 4.10: Results of Aggregate Crushing Value Test for 7 days in Chemical Solution and Water. 4.5.1 Analysis of limestone aggregate for 7 days in solutions Mg SO4 + Na NO3 and 7 days in water. According to Figure 4.10 above, the results of the ACV test can be elaborated by means of comparison to the specification of JKR standard. The analysis towards the strength of the aggregate as compared to the value in specification stated in JKR specification can be best explained with the following questions below:( i ) What is significance of the test results shown from the chart above? From the bar chart in Figure 4.10 the two specimens, which were immersed in chemical solution and water separately, were considered acceptable because the percentage of aggregate crushing value is below JKR standard specification. In 75 this respect, the limestone aggregate does not have a strength problem as the material to be used in building construction since the allowable crushing in JKR specification is higher than the actual tests (40%> 29.8%). ( ii ) How significant the ACV test compared to the cube test? Since the compressive strength of the cube tests for the limestone concrete is above the specified strength in JKR specification and is considered acceptable, it is imperative to discover the actual strength of the limestone aggregate through aggregate crushing value test with respect to the material properties. More information will lead to more established. 4.5.2 Analysis of limestone aggregate for 28 days in solutions Mg SO4 + Na NO3 and 28 days in water. Crushing values of limestone aggregate compared to JKR Standard for 28 days. 40 40 31.24 35 27.48 30 Percentage 25 Crushing 20 15 (% ) 10 5 0 Specimen and1 JKR Specification LIMESTONE IN SOLUTION LIMESTONE IN WATER JKR SPECIFICATION Figure 4.11: Results of Limestone Aggregate Crushing Value Test for 28 day in Chemical Solution and Water. 76 From the bar chart above, the results of the aggregate crushing value test can be summarized as the following:( i ) The results of 28 days are satisfactory since the ACV is below the JKR standard( 31.24% < 40% ). ( ii ) It is not much different between the limestone in chemical solution and in water for the aggregate crushing value. Limestone in Soluble = 31.24% Limestone in Water = 27.48% Difference = 3.76% 4.5.3 Analysis of Granite aggregate for 28 days in solution Mg SO4 + Na NO3 and 28 days in water. Crushing values of Granite aggregate for 28 days in Solution and Water. 40 40 35 30 19.6218.43 Percentage 25 20 Crushing(% ) 15 10 5 0 Specimen and1 JKR Specification Granite in Solution Granite in Water JKR Specification Figure 4.12: Results of Aggregate Crushing Value of Granite for 28 day. To appreciate the results from Figure 4.10, 4.11 and 4.12, an analysis between the limestone and granite for aggregate crushing value is very significant 77 in this research. The most important part of this study is on the influence that the method of immersion into chemical solution and water has towards the strength of both limestone and granite, respectively. Since both limestone and granite aggregates have performed minimum values of ACV compared to JKR standard specification, both of the aggregates can be used for concrete structure in building works. Further discussion of this study will focus on next chapter which is under discussion part. CHAPTER 5 DISCUSSION 5.1 Introduction. Before further discussion in this chapter, I would like to focus the issue of this study with respect to the strength of the aggregate according to the JKR specification for building works only. Our main issue in this chapter is related to the material properties and part of the study’s scope is to ascertain weather the strength of the aggregate can be affected by chemical attack such as magnesium sulphate and natrium nitrate below ground level. However, the end results of this study will possibly show a few signs on the behavior of concrete structure due to chemical attack. 5.2 Discussion on the texture of the aggregate. Since concrete structure is to be designed according to BS 812, and three quarters of the component is aggregate, so that the texture and shape of the material are the first important things to be considered to require a good bonding prior to the compressive strength of the concrete structure. For this particular reason, the selected aggregate to be tested during construction period must have a standard testing in which “sieve analysis” is the 79 most popular methods of testing in the field of construction industries. In this testing, the aggregate should pass sieve analysis according to M.S 7.5 section 2 to 6 which is mentioned in JKR specification page 36 under clause 3.4 aggregate grading and 3.5 sampling and testing of aggregate.( Refer Appendix A ). Under this testing the aggregate was sieved through sieve sizes of 20mm, 14mm, 10mm and 5mm. The results of the testing were recorded and graph plotted as shown in figure 4.1 under Chapter 4. The results were mentioned in previous paragraph 4.2.1. What can be discussed in this chapter are the objectives of this research. The characteristic of the material to be used is the most important thing for supervisors to be bear in mind during construction period. Engineers shall have more knowledge on the behavior of the concrete as well as aggregate, and regular check should be done on site. During the experiment, there were many factors found in this study prior to the performance of the concrete. The factors involved are as follows:- 5.2.1 The source of the Limestone aggregate. To initiate the aggregate, the source of the raw material should be identified first before recognizes and testing the aggregate in the laboratory. This is very important because different places have different quality and mechanical properties. How do these factors contribute to the strength of the concrete? To answer and discuss this question, it is another scope to be provided and a relevant answer can be found. However, at the current time, the irregularities and surface texture will definitely be one of the criteria during initial stage of selecting the raw material. By visual method, we can recognize weather the raw material is a good quality for construction purposes. 80 5.2.2 Discussion on the Sieve Analysis. Sieve analysis is the only type of test to be considered firstly to make sure the aggregate is well graded according to M.S. 7.5 section 2 to section 6. The specific function of this test is to get a better bonding between aggregate and cement paste. What say about sieve analysis results? Let’s refer to the graph obtained from the test as mentioned in Figure 4.1under Chapter 4. From the graph in Figure 4.1, we can describe the results of the test as the following:- ( a ) The graph shows the relationship between aggregate and sieve size, drawn as percentage passing versus sieve size on Y-axis and X-axis respectively. ( b ) The maximum and minimum percentage are plotted as black line whereas actual passing is plotted as red line. From the graph, the red line falls within the region of maximum and minimum line, implicating that the aggregate is well graded and considered as passing the sieve analysis test. Well graded aggregate is the stringent specification to be strictly followed because of the concrete depends on its sizes. Once the sieve analysis has passed, it is very important to test the aggregate in term of its flaky and elongation properties which contributes also to the strength of the concrete. 5.3 Discussion on Flaky and Elongation Properties. 5.3.1 What can be discussed on the Flaky and Elongation Properties? Since strength is related to the bonding between aggregate and cement paste, surface contact and texture of the aggregate are the main factors to the composition in concrete structure. To elaborate further, the flaky and elongation properties should be firstly acknowledged. 81 The best way to recognize are through the textures as shown in figure 5.1 below:- ( i ) Flaky shape ( ii ) Elongation shape ( iii ) Angular shape (Recommended shape) Figure 5.1: Types of Aggregate Texture. To have a good strength on the texture of the aggregate, flaky and elongation does not allowed in concrete structure. The allowable percentage for M.S. 30 is 40% and this is according to specification as stated in JKR contract document (Refer to appendix B). Through Figure 5.1 and the description above, obviously the function of the flaky and elongation test should be clearly understood. From the test results of this study, it is clearly recognized that limestone aggregate from Gunong Panas Kg. Ulu Gali, Raub can be used in construction because the flaky and elongation index are 19.7% and 18% respectively, and this is below 40% which is considered acceptable. So through this study, flaky and elongation are textures not the major problem about concrete structure below ground level. 5.4 Discussion on the Concrete Cube Strength. From paragraph 5.1, 5.2 and 5.3, it was obtained that all the tests done had passed and they were not the major problems of concrete structure in this study. Why should a cube test be done for this research? The answer to that question is the main topic of our discussion in this chapter. 82 Cube strength is a part of concrete construction for obtaining the grade of concrete according to the specification. Normally 6 cubes are prepared for testing purposes. For this particular study, 24 cubes have been prepared and also have been tested to the required strength of 7 days, 14 days, 21 days and 28 days. During the preparation of the cubes slump test was done and recorded 70 mm maximum slump was allowed. 5.4.1 Cube Strength 7 days period. According to the results of the tests different strengths was recorded for cubes in the chemical solution and in water. From Figure 4.3 and 4.4, the cube strengths of the three specimens were above the standard of JKR, which is considered acceptable. 5.4.1.1 What’s new finding on the results? The results obtained had been analyzed and can be explained according to the criteria and scope of study. Observations through the test are as follows:- (I) The compressive strength of the cube in Magnesium Sulphate plus Natrium Nitrate was more than the compressive strength in normal water. ( ii ) The concrete cube prepared for grade 25 and standard compressive strength should reach 17 N/mm2 for the 7 day period. ( iii ) From the observations, it shows that the cube in solution ( Mg SO4 + Na NO3 ) reacts with cement paste very fast creating hardening when compared to cube in water. The strength value increased in such a short time, i.e. average value is 26 N/mm2 compared to 22 N/mm2 in water, which is 4 N/mm2 increase, 83 considered very much difference. This also is the answered to the above question on new finding. ( iv ) From this observations, a few factors could have contributed to the strength as follows:- (a) Due to the amount of chemical content, this soluble reacted with the cement paste, filled and occupied the voids prior to becoming more dense and harden the concrete composition faster. (b) During the tests, the weight of each concrete cube was recorded and it showed that different cubes weight differently weight( Refer Appendix C ). The cube in chemical solution was recorded heavier than in water. (c) Another finding through the test was the colour of the cube, formed in white for chemical solution whereas grey in water. (d) The last observation in the test was about the crack failure. Different pattern exists between the cubes failure pattern of crushed for the cubes are shown through Figures 5.2(a) and (b) below:- Figure 5.2 ( a ) – Failure Pattern in Water. 84 Figure 5.2 ( b ) – Failure Pattern in Chemical Solution. ( v ) To continue the discussion on this matter, lets have a look at the cube strength at 14 days and 21 days for data purposes. 5.4.2 Cube Strength 14 days period. According to the results from table 4.4, it is obvious that the strength increases as time increases. This is possibly due to the same criteria as mentioned for the strength 7 days period. 5.4.3 Cube Strength 21 days. Since concrete cube increases in compressive strength as time goes by the significance of this has served little purpose. This is because the chemical has reacted in the composition of the concrete and has recorded a significant value for immersion into chemical solution. For this case study, there was not enough time to get genuine results since the duration is only for 28 days. However the results obtained through this study can predict a possibility of concrete behavior when mixed with chemical. For this particular discussion, I would like to focus on the 85 factor of time. In the next study it would be better to put the cube for one year into the ground and do the tests for a more practical and genuine result. At the same time relate the results in the chemical solution and water in the laboratory for the same period. Now let’s analyze the results of the 28 days period the cube in chemical solution and in water. 5.4.4 Cube Strength 28 days. With reference to Table 4.4, it can be noticed that the strength differs slightly. As strength goes higher for 7 days, 14 days and 21 days in chemical solution, the results suddenly change for that of 28 days. The strength shows lower than that in water, about 0.34 N/mm2, and this should be the criteria to be taken into consideration to make this study significant and beneficial for construction industries. This shows that chemicals are the elements to be seriously considered to produce good, durable and quality concrete structure. Once there is a sudden reduced strength in the cube at 28 days, it must be studied and adjustments made to overcome this problem. This is an interesting topic to be discussed because the objective of this study is to explore the use of limestone aggregate in construction industries without prejudice. To make this statement reality there must be a specific answer and good results about the strength of concrete product. A longer study should be carried out in future for better information about the chemical attack in concrete structures. 86 Compressive Strength(N/mm2) Cube Strength Versus Duration 40 35 33.4 30 33.06 29.5 26.16 25 20 Cube Strength 15 15 10 5 0 0 10 23 37 4 14 5 21 628 Duration Figure 5.3(a): Average Cube Strength of Limestone Concrete in Chemical Solution. Cube Strength Versus Duration 40 Compressive Strength(N/mm2) 35 30.5 30 33.4 26.8 25 23.1 20 Cube Strength 15 12 10 5 0 0 01 32 37 4 14 5 21 628 Duration Figure 5.3(b): Average Cube Strength of Limestone Concrete in Water. Figure 5.3(a) and (b) are the results of cubes strength for 7 days, 14 days, 21 days and 28 days summarized in graph. Figure 5.3(a), showing a sudden drop of strength on limestone concrete cube immersion in chemical solution for 28 days. The reduced of strength has a significant on the problem of limestone below ground level as mentioned in JKR specification. Where as figure 5.3(b) showing the results of limestone concrete cube immersion in water, proven that the strength increased as time increased. From the tests carried out, many information 87 was obtained related to the strength and comparison was made to suit the objective of the study. In the analysis of this study, the strength of the concrete and the strength of the aggregate are two things with different answers. Concrete strength is the result of combination strength between cement paste, fine aggregate, coarse aggregate plus water, where as aggregate strength is the value of it’s original strength. This can be discussed in the next paragraph which is under Aggregate Crushing Value test. 5.5 Discussion on the Aggregate Crushing Value Test Results. Aggregate Crushing Value (ACV) is a test that will show the strength of the original aggregate in term of percentage for crushed aggregate weight compared to the whole specimen weight. Before moving on, let’s have a look at Table 5. 2 below to explain the strength of the aggregate in the ACV test. Table 5.1 The results of ACV test for Limestone and Granite Test 1 Test 2 Test 3 Test 4 Test 5 Test 6 ACV Limest Limest- Limest Limest Granite Granite stan -one one -one -one In In -dard In In In In Chemi Water spec. Chemi Chemi Water Water -cal -cal -cal ( 7 days ) ( 28 days) solu- solu- tion tion ( 7 days ) 29 % (28 days) solution of JKR. (28 days) (28 days ) 31.24% 29.8% 27.48% 19.62% 18.43% 40% 88 5.5.1 Discussion on ACV test for 7 days. The results for 7 days period are as mentioned in table 5.1 above through test 1 and test 3. All the value is below 40% which is considered acceptable. The finding of this test is almost the same about percentage 29% and 29.8% respectively. This result giving a difference answer compared to test 2 and test 4, however test 5 and test 6 shows a significant value. What can be explained on the chemical attack of this test? The main issue is the chemical attack in the concrete whether limestone in the solution of magnesium sulphate plus natrium nitrate is the source of the problem. According to the results from Table 5.1 above, it is proved that concrete effect on chemical reaction more in solution compare to water. However for the case of 7 days test, value in chemical solution is less than value in water, further study should be carried out in the future to get a significant answer and methods to overcome the problems. Through the end result of the test it is proved that limestone crushes more than granite. The value of the test can be summarized in figure 5.4 (a) and (b), (c) and (d) below:- 89 Percentage Crushing(%) Limestone 28 days ACV test 45 40 35 30 25 20 15 10 5 0 40 31.28 27.48 Specimen in Solution Specimen in Water JKR Specification Specimen and1 JKR Specification Figure 5.4(a): Results of Limestone ACV Test for 28 days in Chemical Solution and Water. Since the value of ACV test are below JKR specification (40%), however the issue of chemical attack to concrete is slightly have a significant. From figure 5.4(a) above shows that limestone aggregate crushed more in chemical solution compare in water. Figure 5.4(b) Results of Granite ACV test for 28 days in Chemical Solution and Water. 90 Percentage Crushing(%) ACV test for Granite in 28 days. 45 40 35 30 25 20 15 10 5 0 40 Specimen in Solution 19.62 18.48 Specimen in Water JKR Specification Specimen and1 JKR Specfication Figure 5.4(b) Results of Granite ACV test for 28 days in Chemical Solution and Water. Figure 5.4(b) above, shows that granite aggregate less affected to chemical attack compared to limestone aggregate. The results are shown through the values obtained in figure 5.4(a) and 5.4(b) above. The summary of the results can be tabulated in Table 5.2 below:- 91 Table 5.2: Results of ACV test for Granite and Limestone (28 days). Aggregate 28 days in Chemical 28 days in Water. Solution (%) (%) Granite 19.62 18.48 Limestone 31.28 27.48 Results of Granite, Limestone compared to JKR Specification (28 days) 40 Percentage 30 Crushing 20 (% ) 10 40 31.24 19.62 0 Specimen and1 JKR Specification LIMESTONE GRANITE JKR SPEC. Figure 5.4(c) Results of ACV test for Granite and Limestone aggregates in Chemical Solution (28 days). From the results obtained in figure 5.6(c) above, it shows that percentage of the limestone crushes more higher than the granite. The limestone percentage is 31.24% compare to granite 19.62%, the differences is 11.62% proved that the effect of chemical reaction is more on the limestone. Where as in the water the 92 results is less than 30% as shown in figure 5.4(d) below, this value is within the JKR specification and can be used to super structure for building works. Results of Granite, Limestone compared to JKR Specification (28 days) 40 40 Percentage 30 Crushing 20 (% ) 10 27.48 18.48 0 Specimen and1 JKR Specification LIMESTONE GRANITE JKR SPEC. Figure 5.4(d) Results of Granite and Limestone Aggregate on ACV test for 28 days in Water. CHAPTER 6. CONCLUSION AND RECOMMENDATION. 6.1 Introduction. All the tests had been carried out and the results were obtained, finally the conclusion should be made. The results of cube tests has obtained during the research and served the study objective relating to strength and performances of limestone concrete. From ACV test shows that the limestone crushed higher compared to granite, significantly suit the second objective of this study. All the tests involved in the study are sieve analysis, flaky/elongation index, cube strength and aggregate crushing value test has been carried out in Highway Laboratory of UTM Skudai on January 2005 and the results was shown in chapter 4. The methodology of this study was mentioned and described in chapter 3. The final objective of this study is about the use of limestone aggregate as an alternative material without prejudice. Since the results of cube strength in water and in chemical for 28 days was accordance to JKR specification, definitely limestone concrete was proved can be used for super structure in construction industries, to meet the last objective. However for substructure, further study about the chemical attack should be carried out and this will be mentioned under recommendation. 94 6.2 Conclusion. Conclusion can be summarized as the followings:- a) Limestone properties and its performances was been shown through results of laboratory tests which include sieve analysis, elongation/flakiness index, cube strength and aggregate crushing value. This statement has served the purpose of study on the information for limestone properties. b) Comparison of results of crushing value to granite related to aggregate strength was made, granite having lower crushing value as compared to limestone( 19.62%< 31.28%), these also has suit the second objective of this study. c) Information about limestone aggregate was known through appropriate tables and graph, beneficial in the use local material and can provide on the demands of the materials to serve the third objective of this study. d) Since limestone aggregate meet the JKR specification in all the tests carried out, it can be an alternative material in concrete superstructure construction. However concrete below ground level (substructure), JKR has a significant reason during the preparation of specification. This is the interesting topic to focus and further study on how to overcome this problem should be carried out in the future. 6.3 Recommendation. During the research I realized that the time factor is very important to overcome the problems. In this study case about chemical reaction, I would recommend that in the future the cube test and ACV test should be carried out for a longer period up to a maximum of one year duration. I also would like to 95 recommend the cubes to be prepared should be buried in the ground for one year period before testing and shall compare to normal condition. 96 REFERENCE: 1. Ketua Pengarah Kerja Raya Malaysia, JKR 344A Standard Specifications for Building Works, Incorporating Amendments until DGPW Circular No.7/1989. 2. A.M. Neville.(1995) Properties of Concrete. Fourth and final edition. England. Addison Wesley Longman Limited. 3. Negeri Pahang Darul Makmur. Jabatan Kerja Raya. Contract Document. Poject: Membina Dan Menyiapkan Masjid Baru Di Mukim Sega, Raub, Pahang Darul Makmur. Contract No: S/PHG/R/DK/283/97. Jurutera Daerah, Jabatan Kerja Raya, Raub. 1997. 4. A.C. McLean C.D.Gribble. 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Erko M.A and Seckin, M. “Review Of effects of loading rate on concrete in compression” Journal of structural engineering. Dec. 1991, Vol. 117, No. 12 Pp 3645 – 3649. 19. Ezeldin, A.S and Aitcin, P-C. “Effects of coarse aggregate on the behaviour of normal and high-strength concrete”- Cement, concrete and aggregate. – Winter 1991, Vol. 13, No. 2 pp 121 – 124. 20. Durwing, T.A. and Hicks, M.C. “ Using microsilica to increase concrete resistance to aggressive chemical” Concrete international, Mar 1991, Vol. 13 No. 3 pp 42 – 48. 21. Collins, R.J. “Alkali aggregate reactivity in dense concrete containing synthetic or porous natural aggregate”- Cement and concrete research, Mar 1989, Vol. 19 pp 278 - 228. 22. Goldmen, A. and Benlur, A. “Bond effects in high-strength silica-fume concrete”. – ACI materials Journal, Sept. – okt. 1989, Vol. 86, No. 5 pp 440 – 447. 99 APPENDIX A1 100 APPENDIX A2 101 APPENDIX B 102 APPENDIX C1 103 APPENDIX C2