Effect of lightweight aggregates on the mechanical properties and brittleness of lightweight aggregate concrete

The influence of volume fraction and aggregate properties on the mechanical performance of lightweight aggregate concrete (LWAC) were studied. A new Shape Index that described the shape characteristics of lightweight aggregate (LWA) has been proposed and its effects on resulting LWAC were evaluated. Test results substantiate that the proposed Shape Index had a great influence on the mechanical properties of LWAC.Crack development, failure characteristics and stress strain curves of LWAC were studied and the concept of the proportional strain ratio was introduced to evaluate the brittleness of LWAC. Test results showed that higher volume content of LWA resulted in a more brittle failure. It was also found out that for similar concrete strengths, LWAC was comparatively brittle than normal weight concrete (NWC).

► Effect of volume fraction and LWA properties on mechanical performance of LWAC was examined.
► Shape index of LWA has been proposed and its influence on the LWAC properties has been discussed.
► A simple method to evaluate the brittleness of LWAC is presented.