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| 摘要: |
| 研究了石英砂、黄砂及特细砂这3种常用砂子对苯丙乳液水泥砂浆（简称改性砂浆）的减水性能、强度、韧性和开裂性能的影响．试验结果表明，砂子越细，苯丙乳液的减水作用越小，改性砂浆的强度越低．用细度模数接近的石英砂和黄砂分别配制的苯丙乳液水泥砂浆抹在模塑聚苯乙烯泡沫板上的薄抹灰试样室外存放试验表明，150d以后，只有低聚灰比的改性砂浆试样在边缘出现了少量裂纹，而对比砂浆试样却出现了大量裂纹；用黄砂配制的砂浆试样的抗开裂性能比用石英砂配制的砂浆试样好，改性的黄砂砂浆试样的裂纹数量和长度只有改性石英砂砂浆试样的1／6，未改性的黄砂砂浆试样的裂纹数量和长度只有石英砂砂浆试样的50％左右． |
| 关键词: 苯丙乳液水泥砂浆 力学性能 砂子 裂纹 薄抹灰 EPS板 |
| DOI： |
| 分类号:TU528.41 |
| 基金项目:上海市建设技术发展基金资助项目(Z0402116) |
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| Effect of Fine Aggregate on Mechanical Property of Styrene-acrylate Copolymer Emulsion Modified Cement Mortar |
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ZHONG Shi-yun HE Hong-zhu
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| Abstract: |
| The influence of polymer addition and sand type on the water-reducing,strength and cracking properties of mortars was studied.The test results show that the strength and the water-reducing ratio decrease with decrease of the particle size of the sand.To compare the anti-cracking properties of thin mortar with a thickness of about 5 mm on expandable polystyrene(EPS) foam board,two series specimens prepared with ordinary sand and silica sand were outdoor exposed.The observation showed that a lot of cracks appeared in the mortars without polymer after about 5 months,while only a few cracks appeared in the polymer-modified mortars with low polymer/cement ratio at the edge of the specimen.The mortars prepared with ordinary sand exhibit better crack resistance than that with silica sand.The amount of cracks and length of the specimen prepared with ordinary sand but without polymer is only 50% of that of silica sand specimen.The amount of cracks and length of the specimen prepared with ordinary sand and with polymer is only 1/6 of that of the silica sand specimens. |
| Key words: polymer-modified mortar,mechanical property,sand,crack,thin mortar,EPS foam plate |
