硅酸盐学报

将自行研制的高吸水性树脂加入砂浆配方,研究了高吸水树脂对不同水灰比下新拌砂浆的流动度、砂浆在干燥养护过程中的体积收缩以及力学性能的影响。研究发现:高吸水性树脂的加入一定程度上降低了砂浆的流动度;砂浆在干燥养护时,在水灰比(质量比)为0.5～0.7范围内,砂浆的总体积收缩与水灰比关系不大,高效减水剂多聚羧酸酯的加入能增大砂浆的体积收缩;在水灰比为0.5～0.6的砂浆干燥养护时,将高吸水性树脂加入到砂浆中可以明显减小其体积收缩;而对水灰比为0.7的高水灰比砂浆的体积收缩改善作用不明显;对于水灰比为0.7的高水灰比砂浆,高吸水性树脂的加入导致其二次浸水时的吸水率增大。此外高吸水性树脂的加入能提高干燥情况下养护后砂浆的力学性能,尤其在较低水灰比的砂浆中作用更为明显。

The effects of the addition of self-prepared super absorbent polymer(SAP) on the properties of cementitious mortar formulations with varied water-cement ratios(m(w)/m(c),in mass) were studied.The degree of fluidity of fresh mortar,dimension shrinkage of hardening mortars during dry curing conditions and the mechanical properties of hardened mortars were measured in order to investigate the impact of SAP on the properties of mortars.It was found that the addition of SAP leads to a decrease of the degree of fluidity of fresh mortars.Under dry curing,the total dimension shrinkage of mortars was proven to be hardly influenced by m(w)/m(c) ratio and to be significantly increased by the addition of polycarboxylic ester(PCE) superplasticizer.The addition of SAP into mortars can remarkably reduce the dimension shrinkage of mortars with a low m(w)/m(c) ratio of 0.5-0.6,while it has little effect on the shrinkage of mortars with a m(w)/m(c) value of 0.7.Another effect of SAP is that the SAP in mortars results in higher water absorption of hardened mortar with a high m(w)/m(c) of 0.7 after secondary water immersion.The results of mechanical test indicate that SAP can increase the mechanical properties of hardened mortars under dry curing conditions,especially for mortars with a low m(w)/m(c) ratio.