掺再生砖粉UHPC高温后的残余断裂能研究  

Study on residual fracture energy of UHPC with recycled brick powder after high temperature

作　　者：杨建强 YANG Jianqiang(Zhengzhou Traffic Infrastructure Quality Inspection Station,Zhengzhou 450008,China)

机构地区：[1]郑州市交通基本建设质量检测站,河南郑州450008

出　　处：《混凝土与水泥制品》2025年第2期53-57,62,共6页China Concrete and Cement Products

基　　金：国家自然科学基金项目(52178258);河南省交通运输厅科技项目(2021J3)。

摘　　要：研究了目标温度(25、200、400、600、800℃)、再生砖粉(RBP)取代率(0、30%、50%)、冷却方式(自然冷却、水冷却)对掺RBP的超高性能混凝土(RBP-UHPC)试件荷载-挠度曲线、残余断裂能的影响,并基于此建立了高温后RBP-UHPC残余断裂能的计算模型。结果表明:高温(200~800℃)后,RBP-UHPC试件的荷载-挠度曲线呈弯曲硬化特征;自然冷却和水冷却RBP-UHPC试件的残余断裂能随目标温度的升高均呈先增后降的趋势;在自然冷却条件下,当目标温度为25、400、600、800℃时,RBP-UHPC试件的残余断裂能随RBP取代率的增加呈先增后降的趋势,而当目标温度为200℃时,RBP-UHPC试件的残余断裂能随RBP取代率的增加呈先降后增的趋势;相较于水冷却,高温(200~800℃)后自然冷却RBP-UHPC试件的残余断裂能相对更高;建立的高温后RBP-UHPC残余断裂能计算模型的相关系数R2大于0.920,精度较高。The effects of target temperature(25,200,400,600,800℃),substitution rate of recycled brick powder(RBP)(0,30%,50%),and cooling method(naturally cooled,water cooled)on the load-deflection curves and residual fracture energy of ultra-high performance concrete specimens with RBP(RBP-UHPC)were investigated,and based on this,a model for calculating the residual fracture energy of RBP-UHPC after high temperature was established.The results show that,the load-deflection curves of RBP-UHPC specimens after high temperature(200~800℃)show the bending-hardening characteristics.The residual fracture energy of naturally cooled and water cooled RBP-UHPC specimens shows the tendency of first increasing and then decreasing with the increase of the target temperature.Under the condition of naturally cooled,when the target temperatures are 25,400,600 and 800℃,the residual fracture energy of RBP-UHPC specimens first increases and then decreases with the increase of the substitution rate of RBP,and when the target temperature is 200℃,the residual fracture energy of RBP-UHPC specimens first decreases and then increases with the increase of the substitution rate of RBP.Compared to water cooled,the residual fracture energy of naturally cooled RBP-UHPC specimens after high temperature(200~800℃)is relatively higher.The correlation coefficient R2 of the model for calculating the residual fracture energy of RBP-UHPC after high temperature is more than 0.920,indicating that the accuracy of the model is high.

关 键 词：再生砖粉(RBP) 超高性能混凝土(UHPC) 冷却方式 断裂能 计算模型 

分 类 号：TU528.041[建筑科学—建筑技术科学]