Characteristics of Crack Growth in High Performance Concrete Subjected to Fire

作     者：GaifeiPENG SammyYinNinCHAN JianhuaYAN YefengLIU QuanxinYI 

作者机构：FacultyofCivilEngineering&ArchitectureBeijingJiaoTongUniversityBeijing100044China Wong&ChengConsultingEngineersLtd.HongKongChina BeijingUniversityofTechnologyBeijing100022China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2005年第21卷第1期

页      面：118-122页

核心收录：

学科分类：0817[工学-化学工程与技术] 0806[工学-冶金工程] 08[工学] 081304[工学-建筑技术科学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0802[工学-机械工程] 0813[工学-建筑学] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：The authors gratefully acknowledge the financial support of both the National Natural Science Foundation of China(project No.50108001) the Pandeng Foundation Project of Beijing Jiao Tong University 

主　　题：High performance concrete Fire resistance Explosive spoiling Crack growth Vapor pressure 

摘      要：An experimental investigation was conducted to identify the characteristics of crack growth in high performance concrete (HPC) subjected to fire, including two parts of work, i.e. crack growth resistance determinations and cracking observations, using concrete of three strength grades 40 MPa, 70 MPa, and 110 MPa. The crack growth resistance curves (R-curves ) of HPC subjected to high temperatures were determined using notched three-point bend beam specimens of 100 mm×100 mm×300mm. The R-curve (crack growth resistance curve) flattening shows that the crack growth resistance has been significantly reduced by elevated temperature. Concrete with a higher strength grade has a steeper R-curve, with a higher fracture toughness but a shorter critical crack growth. The shorter critical crack growth means that concrete of a higher strength grade has a more brittle behavior. The concrete cracking observations reveal that the consequences of rapid heating are quite different from those of slow heating. For slow heating at a rate of 0.5℃/min, HPC suffered no obvious cracking below 600℃ even if it had a high moisture content. Explosive spalling is an extreme case of the internal cracking driven mainly by vapor pressure. All these results confirmed the vapor pressure mechanism for spading behavior which should be more significant for denser concrete. The crack growth ranges obtained from the R-curve determination results are in good agreement with those measured in the concrete cracking observations.