冻融环境下蒸养混凝土声发射试验研究  

Experimental study on acoustic emission of steam cured concrete in freeze-thaw environment

作　　者：陈波[1,2] 陈家林 强晟 郑永杰 CHEN Bo;CHEN Jialin;QIANG Sheng;ZHENG Yongjie(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China;China Construction Seventh Engineering Division Co.Ltd.,Zhengzhou 450004,China)

机构地区：[1]河海大学水利水电学院,南京210098 [2]河海大学水文水资源与水利工程科学国家重点实验室,南京210098 [3]中国建筑第七工程局有限公司,郑州450004

出　　处：《华中科技大学学报（自然科学版）》2023年第8期41-46,共6页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(52079049);国家自然科学基金重点资助项目(51739003);国家重点实验室基本科研业务费专项资金资助项目(522012272)。

摘　　要：为研究蒸养混凝土在冻融环境下的强度性能,在5种冻融工况(0,50,100,150和200次冻融循环)下测试了蒸养混凝土的抗压强度,并分析了强度损失率与冻融次数之间的关系.在此基础上,基于声发射信号参数研究了冻融环境下蒸养混凝土损伤的演化规律和过程,以及蒸养混凝土的破裂类型和裂缝发展形式.结果表明,不同冻融工况下的强度损失率范围为4.23%~41.94%.声发射参数的结果显示:冻融环境会加快蒸养混凝土由脆性向延性特征的转变;声发射源的总数量随着冻融次数的增加而减少,冻融200次后的声发射源数量比0次下降了22.26%;蒸养混凝土张拉破裂值所占的比例随冻融次数的增加而降低,最大下降幅度达80.23%;冻融环境能够降低声发射b值的峰值,冻融200次后蒸养混凝土b值的峰值降低了0.18.In order to study the strength performance of steam cured concrete in freeze-thaw environment,the compressive strength of steam cured concrete was tested under five freeze-thaw cycles(0,50,100,150 and 200),and the relationship between strength loss rate and freeze-thaw times was analyzed.On this basis,based on acoustic emission signal parameters,the damage evolution law and process of steam cured concrete in freeze-thaw environment were studied,as well as the fracture type and crack development form of steam cured concrete.The results show that the strength loss rate of steam cured concrete ranges from 4.23% to 41.94%under different freeze-thaw conditions.The results of acoustic emission parameters show that the freeze-thaw environment accelerates the transition from brittle failure to ductile failure of steam cured concrete.The total number of acoustic emission sources decreases with the increase of freeze-thaw times,and the number of acoustic emission sources decreases by 22.26% after 200 freeze-thaw times compared with 0 times.The proportion of tensile fracture value of steam cured concrete decreases with the increase of freeze-thaw times,and the maximum decrease is 80.23%.The peak value of acoustic emission b value is reduced by freeze-thaw environment,and the peak value of b value of steam cured concrete decreases by 0.18 after 200 times of freeze-thaw cycles.

关 键 词：蒸养混凝土 冻融环境 抗压强度 声发射 损伤 

分 类 号：TU528[建筑科学—建筑技术科学]