Techniques of Testing Aggregate Replacement in Hardened Concrete - Case Study Example

Concrete is the most widely used building material used all over the world. The major constituents of concrete are cement, aggregates and water. The cement in the form of binder holds together the natural or artificial aggregates, which comes in coarse and fine form, to get a hard solid mass capable of taking the designed loads from the structure. The combinations of cement and aggregates in various proportions have given different characteristics in concrete that have ensured a wide range of strength requirement in any proposed structure.

All the civil engineering marvels existing on the earth would be indebted to the power of concrete in ensuring its expected quality (Chang et al, 1999). But the rapid increase in the infrastructure development initiatives all over the world has resulted in the consumption of huge quantities of concrete which has put heavy pressure on the environment for the supply of the aggregates. The shortage of natural aggregates has forced them to turn to manufactured aggregates. The manufactured aggregates too had its own problems due to the improper quality control in the production process, poor starting raw material or rock for the manufacture of aggregates etc.

The increasing demand of the aggregates may not be met with the manufactured sand too. Thus the aggregate replacement systems in concrete have been in vogue as a long-term solution for the aggregate crisis and also from the increased quality demand in the construction. Use of various pozzolanic materials like blast furnace slag, silica fumes, fly ash are few such materials that have found to be suitable in this direction (Chang, et al, 1999). The pozzolanic materials are not very reactive by themselves but in presence of cement exhibits cement like characteristics.