海水珊瑚砂粉工程水泥基复合材料高温暴露后的性能研究OA

To enhance the application reliability of coral resources in marine concrete structures under high-temperature environments,this study investigated the effects of different coral sand powder(CSP)volume replacement ratios(0％,25％,50％,and 100％)on the residual compressive strength,spalling behavior,and microstructure of seawater coral sand powder engineered cementitious composites(SCECC)after high-temperature exposure.The test results show that SCECC with a 25％CSP volume replacement ratio maintains good load-bearing capacity and structural integrity below 400 ℃,whereas at a 100％volume replacement ratio,significant strength degradation and delayed spalling occur due to calcium carbonate decomposition and interfacial structure damage.Scanning electron microscopy analysis indicates that an appropriate amount of CSP can optimize the interfacial transition zone structure,while thermal decomposition at high temperatures disrupts the matrix continuity.This study elucidates the high-temperature damage mechanisms and interfacial response characteristics of CSP in SCECC,providing experimental evidence for the design and evaluation of engineered cementitious composites serving in high-temperature marine environments.