砂浆配比对水分蒸发和塑性收缩裂缝的影响  

Effects of Mix Proportions on Water Evaporation and Plastic-Shrinkage Cracking of Cement Mortar

作　　者：刘丽芳[1] 王培铭[2] 杨晓杰[2] 

机构地区：[1]东华大学纺织学院,上海200051 [2]同济大学材料科学与工程学院,上海200092

出　　处：《建筑材料学报》2006年第4期453-458,共6页Journal of Building Materials

基　　金：上海市科委基金资助项目(036511005)

摘　　要：以混凝土小砌块为基板,研究了不同配比砂浆表面的水分蒸发和塑性收缩裂缝情况,结果表明:随着胶砂比和水胶比的减小,水分蒸发总量和水分蒸发速度逐渐减小,塑性收缩裂缝出现较早,裂缝数量及裂缝总权值均有所减小;掺加聚丙烯纤维后砂浆表面的水分蒸发总量和水分蒸发速度等都有所下降,塑性收缩裂缝出现较晚,裂缝数量和裂缝总权值也显著减少;砂浆表面的水分蒸发越快、蒸发量越大,砂浆越容易出现塑性收缩裂缝,且裂缝总量也较大;当砂浆表面水分蒸发速度小于0.7 kg/(m2.h)时,砂浆不会产生塑性收缩裂缝.The water evaporation and plastic-shrinkage cracking of cement mortars with different mix proportions were studied using concrete brick as base material. The experimental results show that with decrease of cement/sand ratio（mc/ms） and water/cement ratio（mw/mc）, the total water evaporated and rate of evaporation decrease, times to the first plastic-shrinkage cracking are shorter, number and extent of cracking decrease too; after cement mortars mixed with polypropylene fiber, the total water evaporated and rate of evaporation decrease, times to the first plastic-shrinkage cracking are longer, number and extent of cracking decrease. Further more, the extent of cracking is correlated with increasing rate of evaporation and total water evaporated, and plastic-shrinkage cracking will not occur in cement mortar if the rate of evaporation is below 0.7 kg/（m2·h）.

关 键 词：水泥砂浆 胶砂比 水胶比 水分蒸发 塑性收缩裂缝 

分 类 号：TU528.58[建筑科学—建筑技术科学]