不同养护条件下膨胀剂对水泥砂浆收缩性影响的研究

Study of Influence of Expansive Agent on Mortar Shrinkage Under Different Condition of Curing

通过对掺加膨胀剂、多种外加剂的三种不同灰砂比的砂浆进行试验 ,在不同养护条件、不同龄期的情况下 ,测定了其收缩值 ,发现膨胀剂能显著降低水泥混凝土的早期收缩 ,也能明显降低潮湿条件下水泥混凝土的中后期收缩 ,但不能降低甚至会加大干燥条件下的水泥混凝土的收缩值 ,因此作者认为 ,在建筑物地下防水工程中应优先采用膨胀混凝土刚性防水 ,但在建筑物屋面工程中不能采用膨胀混凝土(砂浆)刚性防水。

Based on measuring the length change of maortar,which is made in three different cement-sand ratio and with expansive agent or admixtures,it was found that the expansive agent can obviously decrease the shrinkage at early age.However,at middle and later age,when mortar is under wet condition the expansive agent can also obviously decrease the shrinkage,but when mortar is under dry condition it can't do so and even increase the shrinkage.Therefore,the authors consider that it is mecessary to give expansive concrete priority to be use in udergroud waterproof engineering of buildings and can't use it in roof waterproof engineering of buildings.