Lesson Summary

Lesson Summary
Concrete is the most widely used building material in modern-day construction. This composite material is made of four basic materials – Portland cement, fine aggregates, coarse aggregates, and water.

Concrete, which gains its structural strength once it is hardened, is used for making foundations, walls, bridges, dams, footings, etc. In its semi-liquid state, concrete can be poured into forms or molds that act as a support for the wet mixture till it hardens. These job-built concrete forms are assembled by carpenters.

Cured concrete, in spite of having good compressive strength, is relatively weak in tension. To overcome this drawback, concrete is usually reinforced with materials such as steel.

Varying the basic materials results in various types of concrete such as high-strength, general use, mortar, and foundations. It is therefore important to know the basic mix proportions that will give the different types of concrete.

As concrete gains strength by the process of hydration, knowledge of proper curing methods and materials is also essential. If concrete is allowed to dry prematurely, it loses its natural strength and causes cracks on the surface. Rewetting the mixture, in this case, will not restore its strength.

To determine whether the prepared concrete mixture is workable, a special type of test known as the concrete slump test is carried out. This simple test is performed to check the consistency of fresh concrete.

Just like other building materials, accurate measuring and estimating of concrete quantities is a crucial aspect of the construction process, too.