The influence of Recycled Aggregate on the Early Compressive Strength and Drying Shrinkage of Concrete

Abstract

Recycling waste concrete as source for the production of new concrete can help control environmental pollution and the problem of depleted natural aggregates. The effects of using crushed waste concrete as coarse aggregates on strength and drying shrinkage of concrete are investigated and discussed in this chapter. Waste concrete cubes are tested for compressive strength as a compliance of construction specification are crushed and utilize as coarse recycled aggregates in new concrete. To simulate the real life condition, waste concrete with very minimal information about its originality is used in its natural moisture condition. The recycled aggregates are tested for grading, specific gravity, bulk density, impact crushing, and water absorption and the results compared with those for natural aggregate concrete. From the strength point of view the recycled aggregate concrete compares well with natural aggregate concrete. Therefore, it could be considered for various potential applications. With respect to drying shrinkage, the recycled aggregate concrete is found to have comparable shrinkage with the corresponding natural aggregate concrete.