GFRP布加固火灾受损混凝土界面黏结性能研究  

Study on the Interface Bond Performance Between GFRP Sheet and Heat-Damaged Concrete

作　　者：王占银 傅鸣春[2] WANG Zhan-yin;FU Ming-chun

机构地区：[1]青海交通职业技术学院,西宁810003 [2]北京科技大学土木与环境学院,100192

出　　处：《混凝土与水泥制品》2019年第12期56-60,82,共6页China Concrete and Cement Products

基　　金：国家自然科学基金青年基金项目(51508154)

摘　　要：通过对C30混凝土试件设置25℃、100℃、200℃、400℃、800℃五个温控节点,开展了45个GFRP-混凝土单剪试验,研究了火灾温度、黏结长度对GFRP-混凝土界面黏结性能的影响,提出损伤混凝土抗压强度随温度变化的关系式,建立了GFRP-混凝土在高温后的界面切向剥离承载力模型,并基于SEM检测技术探讨了高温下GFRP-混凝土界面力学性能衰减的原因和机理。结果表明,GFRP黏结长度对界面剥离承载力起决定作用,当黏结长度不足时,应采取相应措施降低火烧时间和火烧温度;800℃下,GFRP丝状纤维已与胶体分离,GFRP丝-胶体局部剥离是导致GFRP-混凝土构件整体剥离的主要原因;抗压强度和切向剥离承载力模型有较好的精度,且具有一定安全储备,可供火灾后混凝土现场抗压强度预测及GFRP加固借鉴使用。The single shear tests of 45 pieces of GFRP-concrete were carried out by setting five temperature control nodes of C30 concrete specimens at 25 ℃, 100 ℃, 200 ℃, 400 ℃ and 800 ℃, the effects of fire temperature and bonding length on the bond performance of GFRP-concrete interface were studied, and the relationship between compressive strength and temperature of damaged concrete was put forward, and the interface tangential compressive bearing capacity model of GFRP-concrete at high temperature was established, and the causes and mechanisms of mechanical properties degradation of GFRP-concrete interface at high temperature were discussed based on SEM detection technology. The results show that the bond length of GFRP plays a decisive role in the interfacial peeling capacity, when bond length is insufficient, corresponding measures should be taken to reduce the fire time and the fire temperature. At 800 ℃, the GFRP filament fibers can be separated from the colloid and this is the main factor for the debond of the interface between GFRP sheet and the concrete. The models of compressive strength and tangential peeling bearing capacity have good precision and certain safety storage, which can be used for predicting the compressive strength of concret after fire and GFRP reinforcement.

关 键 词：混凝土 GFRP 火灾 黏结性能 界面 应力退化 

分 类 号：TU528.572[建筑科学—建筑技术科学]