聚丙烯酰胺对砂浆微观结构与性能的影响

Effect of Polyacrylamide on Microstructure and Properties of Mortar

利用聚丙烯酰胺高的增粘性以及良好的水溶性,研究了其作为保水剂对水泥微观结构及砂浆宏观力学性能的影响。结果表明,掺入0.01%~0.2%聚丙烯酰胺使砂浆抗折强度下降12%~45%,抗压强度最高上升20%,最高下降33%,稠度下降38%~58%。聚丙烯酰胺显著改善了水泥的水化热,最宜掺量为0.02%,此时可降低10%的水化放热量。掺入聚丙烯酰胺影响硅酸三钙(C 3S)、铝酸三钙(C 3A)的水化程度及钙矾石(AFt)的形貌。

With polyacrylamide high viscosity and good water solubility,its effect on the microstructure of cement and the macro-mechanic properties of mortar as a water-retaining agent was studied.The results show that adding 0.01%to 0.2%polyacrylamide reduces the flexural strength of mortar by 12%to 45%,the consistency by 38%-58%and the compressive strength increases the maximum about 20%,decreases the maximum about 33%.Polyacrylamide significantly improves the hydration heat of cement.The optimal content is 0.02%,which reduces the hydration heat by 10%.The addition of polyacrylamide changes the hydration degree of tricalcium silicate(C 3S),tricalcium aluminate(C 3A)and the morphology of ettringite(AFt).