FRP Confinement of SCC Incorporating Expansive Agent and Saturated Lightweight Sand

This study investigated the effect of shrinkage, the use of lightweight sand (LWS) as internal curing and an expansive agent (EA) as shrinkage-reducing admixture on the confinement of self-consolidating concrete. Sixty-three concrete filled fiber reinforced polymer tube specimens were tested under axial compression. Using high EA content resulted in reduction in the unconfined compressive strength of concrete while using LWS resulted in up to 30% increase in the unconfined compressive strength at late ages. The coupled effect of LWS and EA increased the confinement effectiveness by 83%. The use of temporary confinement, in the form of rigid formwork, in conjunction with EA increased the confined strength by up to 23%.