Influence of cement paste matrix properties on the autogenous curing of high-performance concrete

A novel approach to has been recently proposed mitigate self-desiccation, one of the foremost problems of high-performance concrete (HPC). It is based on incorporation of pre-soaked lightweight aggregate in the concrete mix. Such aggregate acts as an internal water reservoir preventing reduction of relative humidity in the cementitious matrix. This method is known as "autogenous" or "internal" curing. Recent studies demonstrated that this kind of curing could be successfully applied to obtain improved HPC with reduced sensitivity to cracking. However, the content of lightweight aggregate required to completely eliminate autogenous shrinkage was high, and this caused a reduction of compressive strength and an increase in the cost of the concrete. Recently, a work has been conducted to optimize the internal curing strategy by eliminating autogenous shrinkage while using the smallest possible amount of lightweight aggregate. The effect of grain size, pore structure and type of the lightweight aggregate was studied. The next step in this study-the effect of the properties of the cement paste matrix on the effectiveness of internal curing is discussed in this paper. (C) 2003 Elsevier Ltd. All rights reserved.