脱模时间对掺ZY膨胀剂水泥砂浆孔结构的影响研究

Effect of demold age on pore structure of ZY expansive agent-added cement mortars

本文研究了脱模时间对掺ZY膨胀剂水泥砂浆强度、孔隙率及吸水率等性能的影响。试验结果仅掺加8%ZY膨胀剂1d拆模后,使得水泥砂浆抗压强度降低,但延长带模养护时间可有效提高掺膨胀剂水泥砂浆抗压强度;通过质量法测定水泥砂浆的孔隙率及吸水率试验结果延长脱模时间可有效降低掺膨胀剂水泥砂浆的毛细孔率及吸水率;使用压汞法(MIP)分析了水泥砂浆孔径分布,相比于基准组砂浆,带模养护7d的掺8%ZY膨胀剂的水泥砂浆孔隙直径低于10nm的孔含量变化不大,但20~100nm范围内的孔隙有所降低。

This paper investigated the effect of demold age on the compressive strength,porosity and sorpotivity of ZY expansive agent-added cement mortars.The results showed:the mortars incorporated with 8% ZY expansive agent decreased its compressive strength when the demold age was 1 d,however,the compressive strength was increased significantly when extending the demold age.The results of porosity determined by mass loss method and sorptivity showed that extend of demold age decreased the capillary porosity and sorptivity.The pore size distribution of cement mortar was determined by mercury intrusion method(MIP)and the results showed that:when compared with the control group,the mortar induced 8% ZY expansive with a demold age of 7 dhad a similar content of pores with diameters less than10 nm,however,a significant decrease of the pores with the diameter between 20~100 nm was also observed from MIP results.