Concrete is a ubiquitous building material, widely used in the construction industry. Concrete is made using cement, water and aggregates. It can also feature steel reinforcements and admixtures. The proportion of different materials in the mixture determines its strength. Concrete can be molded into various shapes and sizes. It is very hard and durable. In modern times, it is used for constructing apartments, dams, bridges, pavement blocks, drain covers, benches, swimming pools and much more.
What Are Its Uses in The Construction Industry?
Plain concrete is used in the construction of buildings and pavements. The paste is poured and cured on-site. If there is a requirement of high tensile strength for the structure, reinforced concrete is used. It has steel bars, wires or meshes – which significantly improve its tensile strength. This mix is commonly used for construction of walls, foundations and slabs. The bond between steel reinforcement and concrete must be high to ensure durability.
Precast concrete is poured and cured off-site according to given specifications and simply assembled at the construction site. This mixture, in the form of concrete blocks, staircases, lintels, poles, etc. is widely used for infra development. Precast concrete is also used in the construction of multi-storey car parks and retaining walls. It speeds up the pace of construction because the units just need to be assembled.
Concrete consisting of asphalt and mineral aggregates is used in the construction of roads, airport runways, car parks, etc. Asphalt roads are capable of withstanding heavy traffic without breaking up.
Concrete flooring applications such as in driveways, pathways, interiors and patios can be made aesthetically appealing by adding texture and color. Such surfaces can be designed to mimic stones and bricks for decorative purposes. Concrete treated with hydroelectric acid or sodium bicarbonate also makes for a decorative appearance.
Massive structures such as dams and bridges are all constructed using concrete. Apart from these, concrete is also used for building tunnels. Thus, concrete has a big role to play in the development of infrastructure.
What are Admixtures?
Concrete, as we know, consists of cement, water and aggregates. However, another ingredient can also be used. This is known as admixture. Admixture imparts a specific property to concrete and enhances its quality. It also reduces the cost of construction of concrete.
The different types of concrete admixtures and their functions have been discussed here.
Water Reducing- This admixture decreases the water content, which enhances the mobility of the cement particles in the mixture. This not only improves work-ability but also increases the strength of concrete.
Air Entraining- Air entraining admixtures generate air bubbles, which create space for the water to expand on freezing. They are used to make concrete more resistant against freezing and thawing, salt sulphates, de-icers, etc.
Retarders- These admixtures are used to prolong the initial setting time of concrete, to facilitate long-distance journeys or unconventional placement, gaining time for special finishes and to combat the effect of hot weather.
Accelerators- Accelerator admixtures speed up the process of curing and enhance the rate of gaining strength by concrete. Consequently, the time duration before finishing process can commence is also reduced. Accelerators also help in preventing the adverse effects of cold weather on concrete.
Concrete is an excellent construction material for both residential and commercial structures because of its high durability, energy-efficient properties, safety rating, environmentally suitable properties and economical nature due to long-term savings.