Effect of the Particle Size Distribution of fly Ash on the Pore Structure of Low-temperature Concrete

In order to explore the effect of the particle size distribution of fly ash on the pore structure of low-temperature concrete, the fly ash was prepared with different particle size distribution.Under low temperature condition, the porosity and pore size distribution of fly ash blended cement mortar curing for 7days were tested by mercury intrusion method and analyze the effect of particle size distribution of fly ash on the pore size distribution and porosity of cement were also analyzed.Research shows that: at the same stage and the same temperature, with the decreasing of the particle size of the fly ash, the porosity of cement pastes decreases gradually.At the same time the more harmful hole (>200nm) and harmful hole (50-200nm) in cement stone gradually decrease, while the harmless hole (<20nm) and the less harmful hole (<50nm) gradually increase.The pore structure of cement stone is effectively improved, of which the corresponding macro performance is improved obviously.