Mechanical properties of pavement quality concrete using recycled aggregate

Abstract

The mechanical properties of pavement quality concrete using recycled concrete aggregate (RCA) obtained from the concrete debris as coarse aggregate (CA) are experimentally determined and presented in this paper. M40 grade concrete was tested with conventional granite CA before adding RCA and then CA was replaced by RCA at the rate of 10, 20, 30, 40 and 50%. The concrete was tested in fresh state by slump and compaction factor (CF) value to evaluate variations in workability. The compressive strength and flexural strength of concrete were conducted to ascertain performance in hardened state. The water absorption test was conducted as a part of durability test. The gradual reduction of slump value was noticed after adding RCA as aggregate in concrete. The slump value had been maintained by substituting the superplastizer without varying the w/c ratio. The strength properties were calculated after 3, 7 and 28 days curing. No significant reduction of strength was observed up to the 30% replacement of RCA and the strength was reduced by adding more than 30% of RCA. From the results obtained in this investigation, it was concluded that the RCA could be used up to 40% as CA for pavement quality concrete.