再生粗骨料品质对混凝土抗溶蚀性能的影响  

Effect of quality of recycled coarse aggregate on the corrosion resistance of concrete

作　　者：刘惠 王震 郝亚利 朱平华 王新杰 陈春红 LIU Hui;WANG Zhen;HAO Yali;ZHU Pinghua;WANG Xinjie;CHEN Chunhong(School of Environmental and Safety Engineering,Changzhou University,Changzhou 213164,Jiangsu,P.R.China)

机构地区：[1]常州大学环境与安全工程学院,江苏常州213164

出　　处：《土木与环境工程学报（中英文）》2023年第2期187-193,共7页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(51278073、51878081、52078068);硅酸盐建筑材料国家重点实验室(武汉理工大学)开放基金(SYSJJ2020-14);常州市重点研发计划(应用基础研究)项目(CJ20200079)。

摘　　要：基于硝酸加速溶蚀试验方法,分别对100%取代率下不同品质(Ⅰ类、Ⅱ类和Ⅲ类)再生粗骨料混凝土和天然粗骨料混凝土的抗溶蚀耐久性进行对比研究,并从宏观力学性能退化及内部微观结构损伤方面进一步揭示混凝土抗溶蚀性能经时劣化规律和损伤机理。研究结果表明:高品质再生骨料制备的混凝土抗压强度较高,与骨料物理性能具有良好的对应关系。在溶蚀环境下,再生粗骨料混凝土的抗压强度损失率、质量损失率、溶蚀深度随溶蚀龄期的增长而逐渐增大,但随着粗骨料品质的降低,却并不一定严格增大,会出现阶段性差异。由SEM图像可知,溶蚀前后,低品质骨料混凝土界面过渡区差异明显。由溶蚀深度与溶蚀时间的拟合公式可知,3类品质骨料制备的混凝土均满足软水环境中的水工结构使用要求,低品质(Ⅲ类)再生粗骨料混凝土可用于一代服役50 a的水利工程结构。Based on the method of nitric acid accelerated dissolution test,the comparative study on the corrosion resistance durability of natural aggregate concrete(NAC)and recycled aggregate concrete(RAC)prepared using 100%of recycled coarse aggregate(RCA)with different qualities(class Ⅰ,class Ⅱ and class Ⅲ)is performed.The degradation law and damage mechanism of corrosion resistance of RAC are further revealed from the aspects of macroscopic mechanical property degradation and internal microstructure damage.The results show that the compressive strength of recycled concrete prepared by high-quality aggregate with better physical properties is higher,and there is a good correlation between them.In the corrosion environment,the compressive strength loss rate,mass loss rate and corrosion depth of recycled coarse aggregate concrete gradually increase with the increase of corrosion age,but not strictly increase with the decrease of coarse aggregate quality,and there are periodic differences in different periods.The SEM images show that the interfacial transition zone of low-quality aggregate concrete is obviously different before and after corrosion.According to the fitting formula of corrosion depth and corrosion time,the concrete prepared by three kinds of quality aggregate can meet the requirements of hydraulic structure in soft water environment,and the recycled coarse aggregate concrete with low quality(classⅢ)can be used for the hydraulic engineering structure with 50 years of service.

关 键 词：再生粗骨料 再生混凝土 抗溶蚀性能 耐久性 

分 类 号：TU528.1[建筑科学—建筑技术科学]