建筑结构学报2024，Vol.45Issue(9)：1-12,12.DOI:10.14006/j.jzjgxb.2023.0529
超低温-高温交变环境下UHPC的拉伸行为及其声发射损伤时序演化
Tensile behavior and its temporal evolution of acoustic emission damage of UHPC under alternating cryogenic and elevated environments
摘要
Abstract
To reveal the performance evolution and degradation mechanism of ultra-high performance concrete(UHPC)under extreme temperature environments,the tensile behavior of UHPC in the range of-170 ℃ to 200 ℃ was investigated,and the temperature-variation damage and crack evolution of UHPC were in-situ monitored by acoustic emission(AE)technology.The results indicate that under the alternating cryogenic and elevated environments,the tensile failure of UHPC with straight and hooked-end steel fibers exhibits strain-hardening characteristics.In first temperature-variation cycle,the mechanical properties of UHPC show fluctuations,with the highest at cryogenic temperatures and the lowest at elevated temperatures.After multiple cycling,the mechanical properties of UHPC decrease accordingly.The AE signal generated by UHPC damage contains abundant failure characteristic parameters,and its AE peak frequency morphology differentiates at cryogenic and elevated temperatures,while that exhibits a centralized single peak distribution in other environments.Except for cryogenic temperatures,UHPC cracking in other environments is mainly tensile cracks,and the number of tensile cracks in the hooked-end fiber group is lower than that in the straight fiber group.As the cycling increasing,the number of tensile cracks in UHPC decreases.关键词
超高性能混凝土/超低温/高温/拉伸行为/声发射参数/时序演化Key words
ultra-high performance concrete/cryogenic temperature/elevated temperature/tensile behavior/acoustic emission parameter/temporal evolution分类
建筑与水利引用本文复制引用
何倍,张红恩,赵铭睿,朱新平,任强,张翼,蒋正武..超低温-高温交变环境下UHPC的拉伸行为及其声发射损伤时序演化[J].建筑结构学报,2024,45(9):1-12,12.基金项目
国家自然科学基金项目(U22B2076,52078369),全国建材行业重大科技攻关"揭榜挂帅"项目(2023JBGS01-1),上海市优秀学术带头人计划(22XD1403300). （U22B2076,52078369）
