含氯再生骨料混凝土抗氯离子渗透性能的研究  

Study on the Resistance to Chloride Ion Permeability of Chlorinated Recycled Aggregate Concrete

作　　者：郑建岚[1,2] 王晓敏 张建全 ZHENG Jianlan;WANG Xiaomin;ZHANG Jianquan(College of Engineering,Fujian Jiangxia University,Fuzhou 350108,China;Coordinative Innovation Center for Environmentally Friendly and Energy Saving HPC of Fujian Province,Fuzhou 350108,China;College of Civil Engineering,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]福建江夏学院工程学院,福州350108 [2]福建省环保节能型高性能混凝土协同创新中心,福州350108 [3]福州大学土木工程学院,福州350108

出　　处：《材料导报》2024年第18期110-115,共6页Materials Reports

基　　金：国家自然科学基金联合基金重点支持项目(U1605242);福建省财政厅项目(闽财指〔2022〕840号);福建省科技厅自然科学基金项目(2020J01938)。

摘　　要：采用纳米SiO_(2)溶液浸泡含氯再生骨料以降低骨料含氯量,并在此基础上考虑复掺矿物掺合料,设计16组配合比以制备C40再生骨料混凝土,测定其7 d、28 d的抗压强度与28 d的电通量、Cl^(-)扩散系数。结果表明:再生骨料中的Cl^(-)可提高混凝土7 d的抗压强度,少量降低其28 d的强度,但会大幅度破坏混凝土抗Cl^(-)渗透性能;纳米SiO_(2)溶液改性后骨料含氯量显著降低,与矿物掺合料联合作用将有效提升再生混凝土力学性能与抗Cl^(-)渗透性能;其中,30%粉煤灰与8%硅灰复掺优化效果最佳,Cl^(-)渗透系数较未掺掺合料组降低85.6%。基于含氯再生骨料多重界面与Cl^(-)扩散机理,推导“内渗型”Cl^(-)扩散模型,并将其用于含氯再生骨料混凝土构件服役任意龄期的Cl^(-)含量预测。In order to reduce the chloride ion content in recycled aggregates,nano SiO_(2)solution was used to soak the recycled aggregates.On this basis,16 sets of C40 recycled aggregate concrete mix proportions were designed with the considering of mineral admixtures adding.And the 7 d,28 d compressive strength,28 d electric flux,Cl^(-)diffusion coefficient of recycled aggregate concrete were measured.It was indicated that Cl^(-)in recycled aggregates would increase the 7 d compressive strength of concrete,and slightly reduce the 28 d strength,but degrade the impermeability of concrete significantly.Actually,the chlorine content of the aggregate was significantly reduced after nano SiO_(2)solution modification.The mechanical properties and Cl^(-)permeability resistance of recycled concrete would be effectively improved with the combined effect of aggregate modification and mineral admixtures adding.And the combination of 30%fly ash and 8%silica fume had the best optimization effect,which the Cl^(-)permeability coefficient was reduced by 85.6%compared to the non mixed material group.Based on the multiple interfaces theory and Cl^(-)diffusion mechanism of chlorine containing recycled aggregate,the‘infiltration type’Cl^(-)diffusion model was derived for predicting the Cl^(-)content of chlorine containing recycled aggregate concrete components at any age of service.

关 键 词：含氯再生骨料 再生混凝土 纳米SiO_(2)溶液浸泡 矿物掺合料 抗氯离子渗透性能 

分 类 号：TU528[建筑科学—建筑技术科学]