Physical filling effects of limestone powders, which are stated by compactness change of mixtures of limestone powders and cement, play an important role in the pore structure and strength of cement stone. The compactness of mixture of limestone powders and cement has been analyzed by the method of wet packing density, tested the void structure of cement stone by mercury intrusion porosimetry(MIP) and strength of cement stone. Effects of limestone powders with specific areas of individually 416m2/kg, 841m2/kg, 1243m2/kg on compactness of cement, compressive strength of concrete as mineral admixture, and pore structure of cement stone were studied when its cement is substituted for the mass proportion of 5, 10, 15% with it. The results show that the compactness of powder mixtures and compressive strength of concrete are biggest, and the improvement of pore structure of cement stone is the best when limestone powder is 10%; the compactness of powder mixtures and compressive strength of concrete are bigger, and the improvement of pore structure of cement stone is better when limestone powder is finer. That is to say, the proportion of limestone powder is the best substitution at 10%; physical filling effects of limestone powder are better when limestone powder is finer from particle sizes. It is important guiding meaning for the application of limestone powder in cement materials.
Effect of the Pore Structure of Concrete on the Compressive Strength of Concrete and Chloride Ions Diffusivity into the Concrete