Modifying the performance of concrete made with coarse and fine recycled concrete aggregates

ABSTRACT Tests have been performed on concretes made using recycled concrete as both the coarse and fine aggregate. The recycled concrete was obtained from two laboratory made source concretes of different strengths. Tests were made on the recycled aggregate concrete to measure compressive strength, permeability and porosity up to an age of 168 days. The strength of the concrete made from only recycled coarse aggregate was between 11 to 20% below that of the control; when the natural sand was replaced by recycled fines the figures increased to between 21 and 38%.