Investigating the Use of Recycled Concrete as Aggregates in the Construction of Structural Beams

The World Bank in a decade ago reported a global collective of 1.3 billion tons of solid waste every year with building material accounting for half of this volume annually worldwide. Recycled materials from demolition sites have increased over the years to curtail the demand for natural aggregates (NA). This study investigates the use of recycled concrete aggregates (RCA) produced from high strength concrete and its effects on the mechanical properties of concrete and structural members. Further comparison was made to concrete with steel fibers. The results showed that the compressive strength of RCA concrete was 5% greater than NA concrete. The influence of the properties of durability and crushing resistance of the RCA, which exceeded that of NA, contributed to the higher concrete strengths when compared to NA concrete. Additionally, concrete with RCA and steel fibers had an increase of compressive strength by 16% to concrete without steel fibers. However, no significant increase in the deflection and strain of the beams under third point loading suggest that given the right conditions RCA can be used in place of NA Keywords: Construction waste; engineering sustainability; recycled concrete aggregate; structural members; steel fiber; waste management.