FLEXURAL STRENGTH OF CONCRETE BEAMS WITH RECYCLED CONCRETE AGGREGATES

Construction and demolition wastes are produced every day around die world.This paper presents the results of an experimental study to evaluate the physical properties of the recycled concrete coarse aggregates mixes and the flexural behavior of the concrete beams produced with these aggregates. Twelve concrete mixes were designed and tested using recycled concrete coarse aggregates. The design parameters were Recycled Concrete Aggregate RCA ratio and cement content. Test results of the compressive strength concrete mixes with recycled concrete aggregates gives about 85% of those with natural aggregates. A total of 6 under-reinforced beams with varying reinforcement ratios 0.90% to 1.30% were fabricated and tested under two central loads. The ultimate strength of beams with recycled concrete aggregates RCA is very close to those with natural aggregates indicating the possibility of using RCA to produce structural concrete. The results of ductility and the stiffhess of beams with RCA are equal or higher than those with natural aggregate. The validity of both the ECP-203 and the ACI procedures for calculating flexural strength for beams with RCA was investigated. It was found that the average experimental/calculated load for beams with RCA is 1.05 indicating the validity of the calculations.