River sand with a fineness modulus of 2.6 and two types of
coarse aggregates viz., natural crushed limestone (LS) and recycled
concrete aggregates (RCA) were used in this study. RCA was obtained
from old concrete test samples with compressive strengths
of 30e40 MPa and attached mortar content about 38%. The concrete
samples were crushed and sieved into 4.5e9.5 mm particle