| 摘要: |
| 在水玻璃和氢氧化钠配制而成的碱激发剂作用下,以粉煤灰为主要原材料,偏高岭土为辅助材料,共同制备了高延性偏高岭土粉煤灰基地聚合物（MFA EGC）,并研究了其单轴拉伸性能.结果表明:MFA EGC试件经单轴拉伸后具有良好的多缝开裂特性,裂缝分布均匀,裂缝间距为2~5mm,残余裂缝平均宽度约为25μm；最优配比试件3,7,28d抗拉强度分别为32,37,38MPa,极限拉伸应变可高达68%,64%,52%,初裂强度分别为14,15,19MPa;3种因素对MFA EGC试件抗拉性能的影响程度依次为养护温度>偏高岭土掺量>PVA纤维掺量.通过三点弯曲和单裂缝拉伸试验计算出的MFA EGC应变硬化性能（PSH）指数与由单轴拉伸试验得到的极限拉伸应变变化趋势相吻合,由此很好地解释了这一材料的高延性机理. |
| 关键词: 高延性偏高岭土粉煤灰基地聚合物 粉煤灰 偏高岭土 单轴拉伸性能 |
| DOI：103969/j.issn.1007 9629201905001 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51508329）;桥隧工程系列超高性能混凝土技术研究项目(CTKY ZDXM 2018 003) |
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| Preparation and Tensile Property of Metakaolin Fly Ash Based Engineered Geopolymer Composites |
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KAN Lili1, WANG Wensong1, WANG Jiahao1, DUAN Xinzhi2
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1.School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China;2.Shanghai Municipal Planning & Design Institute Co.,Ltd., Shanghai 200031, China
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| Abstract: |
| Activated by alkaline activator prepared by sodium metasilicate and sodium hydroxide, the metakaolin fly ash based engineered geopolymer composites(MFA EGC) was prepared using fly ash as the main raw material and metakaolin as auxiliary material, and uniaxial tensile property of MFA EGC were explored. The results show that MFA EGC has good multi cracking behavior after uniaxial direct tensile test. The distribution of cracks is uniform, and the crack spacing is in the range of 25mm, and the average width of residual cracks is about 25μm. The tensile strength for the optimum proportion at 3, 7, 28d is 32, 37, 38MPa respectively, and the ultimate tensile strain can be up to 68%, 64% and 52% respectively, and initial crack strength is 14, 15, 19MPa respectively. The order of influence of factors on the tensile properties is as follows:curing temperature>metakaolin content>PVA fiber content. Through the three point bending and the single crack tensile test, it is shown that the calculated pseudo strain hardening(PSH) index is consistent with the trend of ultimate tensile strain by the uniaxial direct tensile test, which can well explain its high ductility. |
| Key words: metakaolin fly ash based engineered geopolymer composite(MFA EGC) fly ash metakaolin uniaxial tensile property |
