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This report includes the study of concrete as a building material for the walls. Concrete is made by mixing cement and fine aggregates of crushed stones with water (see Fig 1).
Figure 1: Mixing Concrete
Source: 123RF Limited
Concrete is known for strength, ductility and durability. These qualities make concrete most suitable for constructing walls of almost every building in the universe, both storey, and semi-permanent. There numerous types of concretes classified depending on design, the range of composition and purpose as well as performance. Some of the most known common types of concretes include: regular concrete, stamped concrete, glass concrete and limecrete. Concretes are also classified according to their strength which includes high-strength concrete, high-performance concrete, shotcrete and ultra-high-performance concrete[ CITATION Var15 l 1033 ].
This report will study concrete for use in building walls, including history and performance of the concrete. The objectives of the study include:
To study the history of concrete.
The performance of concrete in their categories.
To study areas where concrete is used in wall building and its importance compared to other building materials.
The History of Concrete
Concrete over years has existed in different forms from 300BC to present. The history of concrete has its roots in Rome, Israel, and Egypt. The Romans used a primal mix for their concrete; consisted of small stone gravels, coarse sand mixed with hot lime with water. In the place of water for mixing the sand and the stone gravels, the Romans could sometimes use animal blood. To trim the rough edges of their concrete building, the Romans could use horsehair[ CITATION Jes14 l 1033 ]. The oldest concrete flow was found in Israel. The Israelite could burn limestone to produce quicklime which was then taken and with stones gravels and water before is left to settle. This knowledge found its ways to Egypt and Ancient Greece[ CITATION Jes14 l 1033 ].
The Egyptians used mud which they mixed with straws to form bricks. They also used gypsum and mortars made of lime to make pyramids.The modern concrete is made of Portland cement with fine and coarse gravels and stone aggregates, sand, and water. Some other chemicals can be added to the mixture if the concrete is to be used in areas with extreme conditions to make it more waterproof[ CITATION Wil122 l 1033 ].
Performance of Concrete
Based on performance, concrete is categorized into the following types (Maekawa et al., 1999):
High-performance concrete (HPC).
This is a type of concrete that conform to qualities above the normal regular concrete. These qualities include ease of replacement, toughness, high density, permeability and early age strength. This kind of concrete is used in the construction of walls of tall buildings and super and substructure of bridges.
High strength concrete (HSC)
This is a concrete that has a comprehensive strength which is greater than 40MPa. It is made by lowering the water-cement ratio to become less or equal to 0.35. At times, it is mixed with silica fumes which disable formation of calcium hydroxide crystal which might reduce the strength of concrete aggregation bond used in the construction of shear walls.
Ultra-high performance concrete (UHPC).
This is a new type of concrete presently developed by constructors concerned with infrastructure protection. This type of concrete has qualities as being steel fibre reinforces and with materials which have comprehensive strength more than 150MPa[ CITATION Zha14 l 1033 ]. Other contents of this kind of concrete include fine sand grains, silica fume, a special blend of the Portland cement and small pieces of steel fibre. Some of its characteristics include being crack resistant and high ductility power. It used to make liquid walls. This is a design of making whining curtain walls (see Fig 2).
Figure 2: Curtain Walls
Source: Revit & BIM
Micro-reinforced ultra-high power performance concrete (MUHPC).
This is the next generation of ultra-high performance concrete with additional compressive power, more durable and has a higher resistance to abrasion. Some of the characteristics of this type of concrete include resistance to corrosive chemicals, high energy resistance and absorption, high ductility power and resistance to water and high temperature and very durable than all other types of concrete. Another good characteristic of this kind of concrete is that it is resistant to earthquake hence used to build earthquake resistant buildings[ CITATION Red09 l 1033 ]. This concrete is used to construct seat walls (see Fig 3), poured concrete retaining walls and vertical concrete overlays.
Figure 3: Concrete Seat Wall
Source: Houzz Inc.
This report will conclude by citing on various advantages of using concrete and the advantages of the building made using concrete. Advantages of using concrete in construction include[ CITATION Cro08 l 1033 ]:
Concrete is fire resistant and in the event of fire, it cannot facilitate fire spread.
Cement, sand and stone gravels are cheap and affordable.
Low cost of maintenance is required for structures made with concrete.
Concrete has low emission of carbon (IV) oxide compared to other building materials hence does cause environmental pollution
Crow, J. M., 2008. The concrete conundrum. Chemistry World, March, pp. 62-66.
Jester, T. C., 2014. Twentieth-Century building materials: History and conservation. 2nd ed. Los Angeles, CA: Getty Publications.
Reddy, B. V. V., 2009. Sustainable materials for low carbon buildings. International Journal of Low-carbon Technologies, 4(3), pp. 175-181.
Maekawa, K., Chaube, R. and Kishi, T., 1999. Modelling of concrete performance
Wilson, F., 2012. Building materials evaluation handbook. 2nd ed. New York: Springer Science & Business Media.
Zhang, S., Dong, X., Zhang, H. & Deng, M., 2014. Research on deterioration mechanism of concrete materials in an actual structure. Advances in Materials Science and Engineering, pp. 1-6.