Compressive behavior of reinforced concrete columns with recycled aggregate under uniaxial loading

The mechanical properties of recycled aggregate concrete (RAC) may be inferior to those of conventional concrete that contain natural aggregate, but they are sufficient nonetheless for some practical applications in terms of mix design, design specifications, etc., based on results found in the literature. The use of recycled aggregate serves to promote the recycling of concrete waste in the construction industry as well as to preserve natural resources and the environment. This study investigates the compressive behavior of reinforced concrete columns that are made from recycled aggregate and are subjected to monotonic uniaxial loading. Seventeen columns of various types, quality and quantity of recycled coarse and fine aggregate are tested. The failure mode, compressive strength, and ductility of the columns are examined. In particular, the maximum compressive strength of the columns is compared to existing equations found in American Concrete Institute (ACI) 318-08 [1]. A comparison of the test results and the calculated strengths for the axial load capacity of the RAC columns using the above approach indicates that RAC columns fulfill the ACI design strength criteria.