| 摘要: |
| 采用体积法就4种高效减水剂（聚羧酸系、萘系、三聚氰胺系和脂肪族）对水泥砂浆早期自收缩的影响进行了试验研究，并测定了各高效减水剂溶液不同浓度时的表面张力.结果表明：各高效减水剂均增大水泥砂浆的自收缩；掺萘系、三聚氰胺系及脂肪族高效减水剂水泥砂浆的自收缩随其掺量的增加而增大，掺聚羧酸系高效减水剂水泥砂浆的自收缩则随其掺量的增加呈先增后减的趋势；在水泥砂浆流动度相同时，4种高效减水剂增大水泥砂浆早期自收缩程度由大到小的顺序为：萘系、脂肪族、三聚氰胺系及聚羧酸系.分析表明，高效减水剂改变浆体孔径分布是其影响水泥砂浆早期自收缩性能的主要原因. |
| 关键词: 高效减水剂 自收缩 体积法 表面张力 |
| DOI：103969/j.issn1007 9629201306017 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51178339）；“十二五”国家科技支撑计划项目（2012BAJ20B02）；国家重点基础研究发展计划（973计划）项目（2009CB623104 5） |
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| Effect of Superplasticizer on Early Age AutogenousShrinkage of Cement Mortar |
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SUN Zhen ping, YANG Hui, SHUI Liang liang, CHEN Ming, ZHENG Kun peng
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Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education,Tongji University, Shanghai 201804, China
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| Abstract: |
| Influence of 4 kinds of superplasticizer(SP), i.e. polycarboxylate superplasticizer(PC), naphthalene sulphate based superplasticizer(NSF), melamine sulphate based superplasticizer(MSF) and aliphatic superplasticizer(SAF), on autogenous shrinkage(AS) of mortar in early age was studied by using the method of volumetric deformation measurement. The test results show that the 4 kinds of SP in various dosages can increase the AS. AS increases along with the increase of the addition amounts of NSF, MSF and SAF.It increases first and then falls with the dosage increase of PC. When mortars with SP are in the same fluidity, the capability of the SPs that increases the AS is in the following sequence(from strong to weak):NSF, SAF, MSF and PC. The pore size distribution of mortar is changed by superplasticizer is considered as the main way to affect AS. |
| Key words: superplasticizer autogenous shrinkage volumetric deformation measurement surface tension |
