Physical properties of self-curing concrete (SCUC)

In this study the effect of two different curing-agents has been examined in order to compare them for optimizing the performance of concrete. The first used type is the Pre-soaked lightweight aggregate (leca) with different ratios; 0.0%, 10%, 15% and 20% of volume of sand, and the second type is a chemical agent of polyethylene-glycol (Ch.) with different percentages; 1%, 2% and 3% of weight of cement. In the test programme performed in this study, three cement content; 300, 400 and 500 kg/m3, three different water-cement ratios; 0.5, 0.4, and 0.3, and two magnitudes of silica fume as a pozzolanic additive; 0.0% and 15% of cement weight, were used. The physical properties of concrete were evaluated at different ages, up to 28 days. The concrete specimens are subjected to dry-air curing regime (25 °c) during the experiment.The results show that the use of self-curing agent (Ch.) in concrete effectively improves the physical properties compared with conventional concrete. On the other hand, up to 15% saturated leca was effective while 20% saturated leca was effective for permeability and mass loss but adversely affects the sorptivity and volumetric water absorption. Self-curing agent Ch. was more effective than self-curing agent leca. In all cases, both 2% Ch. and 15% leca were the optimum values. Higher cement content and/or lower water–cement ratio leads to more effective results of self-curing agents in concrete. Incorporation of silica fume into concrete mixtures enhances all physical properties.