Effect of prewetting degree of ceramsite on the early-age autogenous shrinkage of lightweight aggregate concrete

•Three stages of early-age autogenous shrinkage of LWAC, namely liquid phase, skeleton-formational phase and hardening phase.•Quantitatively study for the early-age autogenous shrinkage of LWAC with different prewetting degree ceramsite.•Early age autogeneous shrinkage of LWAC decreases with the increase of prewetting degree of ceramsite.

Lightweight aggregate (LWA) can provide internal curing to lightweight aggregate concrete (LWAC) due to the water absorption and desorption capability of ceramsite. Hence, the addition of ceramsite has a strong effect on the early age autogenous shrinkage of LWAC. In this paper, the early-age autogenous shrinkage of LWAC with different prewetting degree LWA was quantitatively studied when the same net water to cement ratio (NWC) or total water to cement ratio (TWC) was used. During the liquid phase and skeleton-formational phase, the positive effect of the 24 h prewetted ceramsite on the early-age autogeneous shrinkage of LWAC is obvious. During the hardening phase, the LWACs show small expansion strains. Therefore the early age autogeneous shrinkage of LWAC decreases with the increase of prewetting degree of ceramsite for the same NWC or TWC.