动/静荷载作用纤维-矿粉-聚苯乙烯混凝土吸能特征研究  

Study on Energy Absorption Characteristics of BF⁃SP⁃EPS Concrete Under Dynamic/Static Load

作　　者：于泽明 陈艳 马嵘萍 胡晓辰 吕祥锋 YU Zeming;CHEN Yan;MA Rongping;HU Xiaochen;LYU Xiangfeng(School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Key Laboratory of Urban Underground Space Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Guodian Jingwei Engineering Technology Co.,Ltd.,Beijing 100192,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083 [2]北京科技大学城市地下空间工程北京市重点实验室,北京100083 [3]北京国电经纬工程技术有限公司,北京100192

出　　处：《材料导报》2021年第S02期669-677,共9页Materials Reports

基　　金：北京市优秀人才培养资助青年拔尖个人项目(2017000021223ZK04);中央高校基本业务费资助项目(FRF-TP-19-009B1)。

摘　　要：地下空间工程常受动载作用后变形破坏,防护结构吸收动力能量可降低其破坏程度,然而有效吸收冲击能量的吸能混凝土材料及其力学性能仍不清晰。基于响应面法中心优化组合原理,采用动/静载联合同步声发射(AE)监测试验方法,借助高精度微观电镜断口形貌扫描技术(SEM),研究聚苯乙烯泡沫(EPS)、矿粉(SP)、玄武岩纤维(BF)关键因子影响混凝土变形的能量蚕食过程,分析玄武岩纤维-矿粉-聚苯乙烯泡沫(BF-SP-EPS)与水泥基体桥连作用关系,得到动/静载荷作用下BF-SP-EPS混凝土微观吸能规律。研究结果表明,EPS颗粒改变混凝土孔隙结构分布状态,动/静载荷作用下BF-SP-EPS混凝土破坏模式均表现为由脆性破坏转向延性破坏,呈现出破碎压密和能量蚕食耗散特征,大幅度提高了变形韧性量,为能量吸收提供有效变形空间;BF-SP-EPS与水泥基体桥连作用对混凝土吸能性能提升显著,与未掺量同类混凝土相比吸能量达71 J,冲击吸收能量提升50%;建立渴求函数优化模型,得到以抗压性能和吸收能为响应目标的最优化BF-SP-EPS配比为:33.7vol%、17wt%、0.13vol%,并采用相同条件试验方法测试验证优化配比的正确性,研究结果为地下空间工程结构吸能防护安全提供有力理论依据。Underground space engineering often suffers from deformation and failure after dynamic load, and the damage degree can be reduced by absorbing dynamic energy by protective structure. However, the energy-absorbing concrete material which can effectively absorb impact energy and its mechanical properties are still unclear. Based on the central optimal combination principle of response surface method, the dynamic/static load combined synchronous acoustic emission(AE) monitoring test method was adopted, and the deformation energy encroachment process of concrete affected by key factors of expanded polystyrene foam(EPS), slag powder(SP) and basalt fiber(BF) and cement matrix was studied by means of high-precision scanning electron microscope(SEM). The results show that EPS particles change the distribution of pore structure of concrete, and the failure mode of BF-SP-EPS concrete under dynamic and static load changes from brittle failure to ductile failure,showing the characteristics of crushing compaction and energy dissipation, greatly improving the deformation toughness and providing effective deformation space for absorbed energy;the bridge effect of BF-SP-EPS and cement matrix can significantly improve the energy absorption performance of concrete. Compared with the same kind of concrete without admixture, the absorbed energy reaches 71 J, and the impact energy absorption increases by 50%;the craving function optimization model is established, and the optimal BF-SP-EPS ratios with the compression resistance and absorbed energy as the response target are 33.7 vol%, 17 wt% and 0.13 vol%. The correctness of the optimal ratio is verified by the same condition test method. The research results provide a strong theoretical basis for the energy absorption protection safety of underground space engineering structures.

关 键 词：动/静载作用 响应面法(RSM) 玄武岩纤维-矿粉-聚苯乙烯(BF-SP-EPS)混凝土 力学规律 变形破坏特征 吸收能 

分 类 号：TU528[建筑科学—建筑技术科学]