| 摘要: |
| 通过测试水分蒸发速率、塑性抗拉强度、塑性收缩应力、抗裂指数和塑性收缩开裂权重值,研究了不同掺量（质量分数，下同）聚丙烯酰胺(PAM)增稠剂对水泥砂浆塑性阶段收缩开裂性能的影响.结果表明:PAM对水泥砂浆塑性收缩开裂有较好的减裂效果,随着PAM掺量的增加,在大风速下水泥砂浆水分蒸发速率总体上呈现减小趋势,但当PAM掺量大于008%时,水泥砂浆水分蒸发速率有所回升;水泥砂浆塑性抗拉强度和塑性收缩应力均随着PAM掺量的增加而减小,当PAM掺量达到006%后不再减小;随着PAM掺量的增加,水泥砂浆抗裂指数呈增大趋势,塑性收缩开裂权重值呈明显减小趋势. |
| 关键词: 塑性收缩开裂 蒸发速率 增稠剂 聚丙烯酰胺 |
| DOI：103969/j.issn.1007 9629201901001 |
| 分类号: |
| 基金项目:“十三五”国家重点研发计划（2016YFB0303200） |
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| Influence of Polyacrylamide on Plastic Shrinkage Cracking of Cement Mortar |
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YANG Xiaojie, DONG Peng, MA Yiping, LI Haoxin
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Key Laboratory of Advanced Civil Engineering Materials of Education Ministry, Tongji University, Shanghai 201804, China
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| Abstract: |
| Effects of different dosage(by mass, the same below) of polyacrylamide(PAM) thickener on the shrinkage cracking properties of cement mortar in plastic phase were studied by measuring the water evaporation rate, plastic tensile strength, plastic shrinkage stress, crack resistance index and plastic shrinkage weighted cracking value. The results show that PAM has a good effect of reducing the plastic shrinkage cracking of cement mortar. With the increase of PAM dosage, the evaporation rate of cement mortar tends to decrease at high wind speed. When the dosage exceeds 008%, the evaporation rate increases. The plastic tensile strength and plastic shrinkage stress decrease with the increase of PAM dosage to some extent and no longer decrease after reaching the critical dosage(006%). The crack resistance index increases with the increase of PAM content, and the plastic shrinkage weighted cracking value shows a significant decreasing trend. |
| Key words: plastic shrinkage cracking evaporation rate thickening agent polyacrylamide(PAM) |
