Concrete Materials.ppt

1. Concrete Materials Presented By Ramkrishna Halder B.Tech Final Year Student (Ceramic Engineering) Roll No. – 91/CER/131002

2. Presentation Outline Introduction : What is Concrete? Types of Concrete Factors affecting Concrete Strength Advantages & Disadvantages of Concrete Properties of Concrete Components of Modern Concrete A pplication of Concrete Summery

3. Objective To give brief information about Concrete. Concrete-properties, composition . Cement-types of cement,mostly used cement . To upgrade our skills on making presentation .

4. Introduction Concrete is mainly composed of Portland cement, Aggregate(Filler), Water and chemical Admixtures. Concrete = Filler + Binder Concrete is versatile construction material. The name concrete comes from the Latin word “Concretus” (meaning compact or condensed). Concrete solidifies and hardens after mixing with water and placement due to a chemical process known as hydration. The water reacts with the cement, which bonds the other components together, eventually creating a stone-like material.

5. Contd. Portland Cement Coarse Aggregate Fine Aggregate Admixtures

6. Types Of Concrete Based on Weight, Concrete can be classified into Four Categories: Ultra-Light Weight Concrete (1200 Kg/m 3 ) Light Weight Concrete (<1800 Kg/m 3 ) Normal Weight Concrete (2400 Kg/m 3 ) Heavy Weight Concrete (>3200 Kg/m 3 ) Based on Strength, Concrete can also be classified into Four Categories: Low-strength concrete < 20 MPa compressive strength Moderate-strength concrete 20 -50 MPa compressive strength High-strength concrete 50 - 200 MPa compressive strength Ultra high-strength concrete > 200 MPa compressive strength

7. Contd. Beside this there are various type of Concrete for different applications that are created by changing the proportions of the main ingredients . Regular Concrete Ready-Mix Concrete Green Concrete High-Performance Concrete Ultra-High Performance Concrete Rapid Strength Concrete Shrinkage Compensating Concrete Fibre-Reinforced Concrete Asphalt Concrete Polymer Concrete Gypsum Concrete

8. Factors affecting Concrete Strength Water/Cement Ratio Age and Curing Condition Aggregates Admixtures

9. Advantages of Concrete More Economical Ability to be cast More Energy Efficient Excellent Resistance to Water High Temperature Resistance Fire Resistance Aesthetic Properties Ability to Consume waste Ability to work with reinforcing Steel

10. Disadvantages of Concrete Low Tensile S trength Lower Ductility (Brittle) Volume Instability Formwork is needed Low Toughness Long Curing Time

11. Properties of Concrete Concrete has relatively high compressive strength, but significantly lower tensile strength . The elasticity of concrete is relatively constant at low stress levels but starts decreasing at higher stress levels as matrix cracking develops. Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete can be damaged by fire, aggregate expansion, sea water effects, bacterial corrosion, leaching, physical damage and chemical damage (from carbonation, chlorides, sulfates).

12. Components of Modern Concrete Aggregates Portland Cement Admixtures Water

13. Aggregates Aggregate is the granular material, such as sand, gravel, crushed stone, crushed blast-furnace slag, or construction and demolition waste that is used with a cementing medium to produce either concrete or mortar . Aggregate should be inert and strong and It forms the skeleton of matrix 60-75 % by volume 25-40 % Paste &1-2 % Voids. All aggregates must be essentially free of silt and/or organic matter.

14. Classification of Aggregate According to Weight difference Aggregate can be Classified into three categories: Normal Weight Aggregate (2400 Kg/m 3 ) Light Weight Aggregate (1120 Kg/m 3 ) Heavy Weight Aggregate (2900–6100 Kg/m 3 ) According to Particle size difference Aggregate can be Classified into two categories : Coarse Aggregate (Size >4.75 mm to 50 mm) Fine Aggregate (Size <4.75 mm) Coarse Aggregate Fine Aggregate

15. Portland Cement Most commonly used cement is called Portland Cement patented in 1824 in England. Portland cement is a finely ground calcium silicate and calcium aluminate of various composition, which hydrate when mixed with water to form initially a plastic mass and end as a rigid continuous structure, with good compressive strength . Cement contains Limestone , clay , cement rock and iron ore blended and heated to 1200 to 1500 C °. Gypsum is added to control setting time. Dicalcium s ilicate (C2S) is the main binder phase of Portland Cement. Portland Cement

16. Types of Portland Cement ASTM C 150 , Standard Specifications for Portland Cement: Type I : General purpose. For use when the special properties specified for any other types are not required. Type II : For general use, more specially when moderate sulphate resistance or moderate heat of hydration is desired . Type III : For use when high early strength is desired . ( limit the C3A content of the cement to maximum 15%) Type IV : For use when low heat of hydration is desired. Type V : For use when high sulfate resistance is desired . ( Maximum limit of 5% on C3A)

17. Physico-Chemical properties of Portland Cement Chemical Requirements of Portland Cement: Components Percentages CaO 60-65 SiO2 21-22 Al2O3 4.0-5.0 Fe2O3 3.0-4.0 MgO 2.0-3.0 Gypsum 2.0-2.5 Free Lime < 1.0

18. Contd. Physical Requirement of Portland Cement: Parameters Theoretical Value Fineness(Specific surface area) 2800-3000 cm2/g Soundness 5 mm (max) Initial setting time >30 min Final setting time < 600 min Compressive strength:   3 day 160 Kg/cm2 7 days 220 Kg/cm2

19. Cement Manufacturing Process Process Flow Diagram:

20. Admixtures Admixtures are ingredients other than portland cement, water, and aggregates. Admixtures are added to the concrete mixture immediately before or during mixing. The use of admixtures in concrete is now widespread due to many benefits- It reduces the amount of water requirement in Concrete. It control the setting behavior of Concrete. It also improves the workability, durability & strength of the Concrete.

21. Classification of Admixtures Admixtures can be roughly divided into three categories: Air-entraining Admixture: This kind of admixture is used to improve the frost resistance of concrete. Chemical Admixture: This kind of admixture is mainly used to control the setting and hardening properties for concrete, or to reduce its water requirements. Water Reducer Superplasticizer Accelerator Retarder Mineral Admixture: They are finely divided solids added to concrete to improve its workability, durability and strength. Admixtures

22. Water Water is the most essential ingredient in concrete. It should be good enough i.e. free of organic matter and excessive chemicals and/or minerals. The strength and other properties of concrete are highly dependent on the amount of water and the water-cement ratio.  

23. Application of Concrete Concrete is a versatile construction Material. Nowadays every structure made up by modern Concrete. Dams, bridges , buildings, towers, toboggans, curbs canoes , murals, statues, submarines, mountains, foundations have been created with the help of concrete.

24. Summary Concrete is a composite material and highly versatile construction material, well suited for many structural applications. It is a mixture of Portland cement, water, aggregates, and in some cases, admixtures. Strength, durability, and many other factors depend on the relative amounts and properties of the individual components. Different types of concrete are there. But nowadays Ready-mix concrete becomes popular due to many advantages. The strength of the concrete highly dependent on water and water-cement ratio and also the curing condition, type of aggregate and type of admixtures used.

25. Contd. Aggregate, Portland cement and admixtures are the main components of the modern concrete. According to the choice of application different types of aggregate are used. Super plasticizers are used to produce high strength concrete. Concrete is the most versatile among all man made materials. Many structures i.e. building, dams, bridges, towers, statues etc. are made up by modern concrete.

26. References F.M. Lea, Chemistry of cement and concrete , 4 th edition. T.D. Robson, High Alumina Cements and Concrete , 2 nd Edition. H.F.W. Taylor, The Chemistry of Cements , 3 rd Edition. J.C. Wilt, Portland cement Technology , 2 nd Edition. S.N. Ghosh, Advances in cement Technology , 2 nd Edition. R.H . Bogue , The Chemistry of Portland cement , 4 th Edition. Wies Baden, Process Technology of cement Manufacturing , 2 nd Edition. YothinUngkoon,ChadchartSittipunt,PichaiNamprakai,WanvisaJetipattaranat,Kyo-SeonKim , and TawatchaiCharinpanitkul , Analysis of Microstructure and Properties of Autoclaved Concrete Wall Construction Materials, J. Ind. Eng. Chem., 13 [7], (2007) 1103-1108. G.C. Isaia , A.L.G. Gastaldini, and R. Moraes , Physical and pozzolanic actions of Mineral additions on the mechanical strength of high performance concrete , Journal of Cement and Concrete Composite, Vol 25, (2003), 69-76. P.K . Mehta , Paulo J.M. Monteiro , Concrete Microstructures , Properties, Materials , 3 rd Edition.

27. Thank You For Attention