Investigation of stress-strain relationship for confined lightweight aggregate concrete

Lightweight aggregate concrete (LWAC) is prone to undergo the aggregate fracture, which causes its failure mechanism are significantly different from that of normal weight concrete. The provision of sufficient lateral reinforcement can effectively improve the synergistic effect between the lightweight aggregates and cement matrix, thus enhancing the strength and ductility of LWAC and expanding its engineering applications. This paper presents an experimental investigation on the uniaxial behavior of twelve LWAC columns designed with different amount and configuration of lateral reinforcement. The equations of the feature points needed for the stress-strain model are established by considering the confinement efficiency of the lateral reinforcement and the actual lateral reinforcement stress at the peak point, and are calibrated using the extensive results of the confined LWAC test database. Test results reveal the working mechanism of confined LWAC and further verify the accuracy and applicability of the proposed model. (C) 2020 Elsevier Ltd. All rights reserved.