低收缩延性纤维增强水泥基复合材料抗氯离子渗透性能

发布时间：2018-06-06 01:06

本文选题：低收缩延性纤维增强水泥基复合材料 + 裂缝　；参考：《建筑材料学报》2017年06期

【摘要】：为研究低收缩延性纤维增强水泥基复合材料(LSECC)抗氯离子渗透性能,首先研究了水胶比、成型方法以及养护龄期对未开裂LSECC抗氯离子渗透性的影响;然后基于LSECC抗弯力学性能特点,通过四点抗弯方法,并同时控制试件底部受拉区变形值,对不同水胶比LSECC进行预开裂损伤;最后分别采用ASTM C1202电通量法和NEL扩散系数法来评价开裂LSECC的抗氯离子渗透性.结果表明:采用挤压成型且水胶比较低、养护龄期较长的未开裂LSECC抗氯离子渗透性较好;开裂LSECC抗氯离子渗透性可分为基材开裂前和基材开裂后2个阶段;随着水胶比的降低,基材开裂后的裂缝数量和宽度均有所减小,抗氯离子渗透性衰减速度减弱;NEL扩散系数法测试结果对开裂LSECC抗氯离子渗透性变化不敏感.
[Abstract]:In order to study the chloride penetration resistance of low shrinkage ductile fiber reinforced cement matrix composites (LSECCs), the effects of water / binder ratio, molding method and curing age on the chlorine ion permeability of uncracked LSECC were studied. Then based on the characteristics of LSECC flexural mechanical properties, through the four-point bending method, and at the same time controlling the deformation value of the tensile zone at the bottom of the specimen, the pre-cracking damage of LSECC with different water-binder ratio is carried out. Finally, ASTM C1202 electric flux method and NEL diffusion coefficient method were used to evaluate the chloride penetration resistance of cracked LSECC. The results showed that the uncracked LSECC with low water glue and longer curing age had better resistance to chloride ion permeability, and the cracking LSECC could be divided into two stages before and after the cracking of the substrate, and with the decrease of the water-binder ratio, the resistance to chloride ion penetration of the cracked LSECC could be divided into two stages: before and after the cracking of the base material, and with the decrease of the water-binder ratio, The number and width of cracks decreased after cracking, and the decay rate of chloride ion permeability was weakened. The results of diffusion coefficient method were not sensitive to the change of chloride penetration resistance of cracking LSECC.
【作者单位】：清华大学土木工程系;清华大学结构工程安全与耐久教育部重点实验室;
【基金】：国家自然科学基金资助项目(51678342) 高等学校博士学科点专项科研基金资助项目(20130002110034)
【分类号】：TU528

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