Effect of Slag on Pore Structure of Hardened Pastes and Hydration of Alite-calcium Barium Sulphoaluminate Cement

摘要

Effect of different blending amount of slag on cement pastes were studied by measuring and analyzing the mechanical property, hydration rate and pore structure of hardened alite-calcium barium sulphoaluminate cement pastes, and using X-ray diffraction and scanning electron microscopy. The results show that, there are much ettringite in the hydration products of alite-calcium barium sulphoaluminate cementi which would efficiently promote the early strength of the cement. Adding slag can cause larger decrease of early strength while the later strength is only reduced to a small extent. When the slag content is 10%, the decrease of compressive strength is the lowest at each curing age and the compressive strength of the hardened pastes at later hydration age can match or even higher than the pure cement paste. Slag can reduce the heat of hydration and hydration rate, fill pores in the sample and equal the distribution of pore structure, so that the microstructure and pore structure of cement pastes at later hydration age are efficiently improved.