中文摘要：

以石灰石微粉（LS）为参照,研究了20、40℃和60℃养护时10%和30%掺量白云石微粉（DM）对水泥砂浆强度的影响,并采用压汞法（MIP）研究了混合水泥砂浆的孔结构。结果表明：20℃和40℃时,LS优于DM促进早期强度发展,但两者差异随掺量增加和龄期延长而减小。提高温度到60℃,对DM砂浆各龄期强度的促进效应均比对LS体系更为显著,且掺量愈大,两者对温度效应的差异愈明显。三种养护温度下,DM与LS的掺入均增加砂浆孔隙率,且掺量愈大孔隙率愈大。10%掺量时,DM与LS对孔径分布影响不大,而30%掺量时两者均明显粗化孔径。与LS相比,20℃时,DM砂浆孔隙率大于LS砂浆,孔径粗化也更为明显;40℃时,DM砂浆孔隙率近似或小于LS砂浆,两者孔径分布类似;继续提高温度到60℃,DM砂浆孔隙率小于LS砂浆,孔径分布优于LS砂浆,且掺量愈大两者差异愈明显。提高养护温度,对DM砂浆孔结构的劣化效应弱于LS砂浆。DM的化学活性对升高温度的响应强于LS,DM反应生成的水滑石利于降低孔隙率并改善孔径分布,促进水泥砂浆强度发展。

英文摘要：

Strength of blended cements mortars with dolomite powder （DM） at different replaced contents, i.e., 10% and 30%, and cured at 20, 40 ℃ and 60 ℃ were investigated. Limestone powder （LS） was also used for the comparison. The pore structure of blended cements mortars were examined by mercury intrusion porosimetry （MIP）. The results indicate that DM and LS have different effects on the mortar strength at various replacement levels and curing temperatures. At 20 ℃ and 40 ℃, LS shows more positive impact on the promotion of the early strength, compared to DM, but this difference decreases with the increase of replacement level and the curing age. Compared to the mortars with LS, increasing the curing temperature to 60 ℃ gives a stronger promoting effect on the strength of mortars with DM, and the effect is more pronounced with the increase of replacement levels. With the incorporation of dolomite or limestone powders, the porosity of mortars increases. At the replacement level of 10%, DM and LS show similar effects on the pore size distribution of mortars. Compared to the mortars with LS, the mortars with DM cured at 20 ℃ have a greater porosities and larger pore sizes. When cured at 40 ℃, the mortars with DM and LS develop the similar porosity and pore size distribution. When the curing temperature is 60 ℃, the mortars with DM show a lower porosity and better pore size distribution, compared to the mortars with LS. DM gives a superior effect on the pore structure of mortars when the curing temperature increases. DM develops a stronger chemical effect at high curingtemperatures and results in the formation of hydrotalcite, which is beneficial to decreasing the porosity, improving the pore structure and promoting the strength of cement mortars.