Effect of coarse aggregate on elastic modulus and compressive strength of high performance concrete

Abstract

A set of high performance concrete mixes, of low water cement ratio and fixed mortar composition, containing six different types of aggregates of constant volume fraction, has been used to check moduli of elasticity at 7, 28 and 91 days. The results have shown that, apart from the aggregates of very low and very high modulus, concrete modulus at 28 days can be predicted quite well by well-known models. Increase in modulus thereafter is slight. Cube strength (about 90 N/mm 2 at 28 days with normal aggregates) is drastically reduced, as expected, by the weaker aggregates and is also reduced (by about 9%) by the stiffer (steel) aggregates.