Free Research Paper About Concrete
Concrete is a composite material made up of a mixture of aggregate, Portland cement, sand and water. Upon heating the mixture to high temperatures up to 1600oC in a rotary kiln, the mixture recombines and gains strength . The history of concrete dates back to 6500 BC in northern Syria. Other constructions made of concrete were also found by the archaeologists in Greece, China, Middle East and the Roman Empire in the ancient times. Concrete finds its uses in the construction of buildings, monuments, statues, roads, sewer systems, pumps, dams and many others. The properties of concrete depend upon its pore space, such as air voids, capillary pores and nanometer-scale pores . While the density of concrete is 2.4 Mgm-3, its tensile strength is 20 GPa. The thermal conductivity is 2 Wm-1K-1 while the property of thermal expansion of concrete is 12 10-6K-1.
Concrete is resistant to frost and its resistance depends on the quality and type of cement used in the mixture. It is non-combustible and possesses excellent fire-resistant properties. Thermal effects produce volume changes in concrete. There are several advantages as well as disadvantages of concrete. Concrete is robust and has a lower life-cycle cost. It is robust and possesses mould ability into any customized shape. Concrete is resistant to wind, water, insects and rodents . It does not rot, decay or corrode. The disadvantages of concrete include low tensile strength and low ductility. Concrete possesses a lower strength-to-weight ratio. Another major disadvantage of concrete is its susceptibility to cracking. Hence, the material deteriorates with age. Concrete shows stains, which are not easily removable if left for a longer period of time. It contains soluble salts, which have the property to cause efflorescence.
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