水泥种类对砂浆收缩性能和孔结构参数的影响

Effect of cement type on shrinkage performance and pore structure parameters of mortar

研究常见水泥种类对砂浆收缩性能和孔结构参数的影响,为水泥的合理选用提供试验参考。采用贵州常见的4种水泥(毫龙水泥、西南水泥、尧柏水泥、中诚水泥),探索砂浆的力学性能、收缩性能和孔结构参数等性能。结果表明:随着养护龄期的延长,砂浆的抗折强度和抗压强度越高,但90 d时4种水泥砂浆抗压强度相差不大于3MPa。砂浆的抗压强度与抗折强度之间呈现出显著的线性关系,折压比呈现出降低的趋势,干燥收缩与自收缩均随养护龄期的延长不断增长,但干燥收缩始终高于自收缩。通过吸水法发现,养护龄期的延长对砂浆孔结构均匀性有细化作用,但4种水泥砂浆的平均孔径相差不大,相差不到0.04。表明水泥产地不同,其性能的表现各异,文中4种水泥的建议选择顺序为:西南水泥>中诚水泥>尧柏水泥>豪龙水泥。

The effects of common cement types in Guizhou on mortar shrinkage properties and pore structure parameters were explored,providing experimental reference for the rational selection of cement.Based on this,four kinds of common cement（ Haolong cement,south west cement,Yaobai cement,Zhongcheng cement） in Guizhou were used to investigate the mechanical properties,shrinkage performance and pore structure parameters of mortar. Results show that with the extension of curing age,the flexural strength and compressive strength of mortar increase,but the difference in the compressive strength of four cement mortar at 90 d is less than 3 MPa. The compressive strength and flexural strength of mortar show a significant linear relationship,and the folding and pressing ratio shows a decreasing trend.Drying shrinkage and autogenous shrinkage of cement mortar both increase with the extension of curing age,but the drying shrinkage is always higher than that of autogenous shrinkage. Through the water-absorbing method it can be found that the prolongation of the curing age had a refinement effect on the homogeneity of the mortar pore structure,but the average pore diameters of the four cement mortars were not significantly different and the difference is less than 0. 04. Based on the above findings,it can be concluded that the performance of cement varies as the cement producing area varies also,it is suggested that the choice of 4 kinds of cement follows the order： southwest cement 〉Zhongcheng cement 〉 Yaobai cement Haolong cement.