EFFECT OF CURING REGIMES ON CHLORIDION PENETRATION OF WHITE HIGH-STRENGTH CONCRETE

The rapid chloridion diffusion coefficient method was used to study the effect of different curing regimes and the use of mineral admixture on chloridion resistance of white concrete. The results showed that the pure white cement concrete had the lowest resistance to chloridion penetration among the three groups of curing regimes. The use of mineral admixtures could greatly reduce the rapid chloridion diffusion coefficient (D_RCM) of the white cement concrete; the D_RCM of the concrete under standard curing was the lowest, the value of matching curing was the second high and that of steam curing was the highest; the second exothermic peak of white cement hydration in the early stage appeared earliest, and its peak was the highest data. However, the cumulative heat release of pure white cement was lower than that of ordinary cement. In addition, the pure white cement concrete had the highest adiabatic temperature rise (ATR) and the highest temperature, the concrete with cement-mineral powder system possessed the second-high ATR and the concrete with cement-mineral powder-limestone powder had the lowest value. Through the pore structure analysis, it could be seen that although steam curing might stimulate the hydration process of the concrete and reduce the porosity, it would promote the pore structure to develop toward the rough pore and would increase the average pore diameter.