Prevention of autogenous shrinkage in high-strength concrete by internal curing using wet lightweight aggregates

Restrained autogenous shrinkage in high-strength lightweight aggregate concrete was investigated. Effects of a partial replacement of normal-weight aggregate by lightweight aggregate on autogenous shrinkage were also discussed. The concrete with saturated lightweight aggregate exhibited no autogenous shrinkage, whereas the normal-weight concrete with the same matrix exhibited large shrink-age. A partial replacement of normal-weight aggregate by 25% by volume of saturated lightweight aggregate was very effective in eliminating the autogenous shrinkage and restrained stresses of the normal-weight concrete, It should be noted that the internal supply of water from the saturated lightweight aggregate to the high-strength cement matrix caused continuous expansion, which may be related to continuous hydration. (C) 2001 Elsevier Science Ltd. All rights reserved.