Stress relaxation characteristics of prestressed GFRP anchor structure in corrosive environment#br#
LI Guowei1，2，WANG Jingqiu1，3，SIDI Kabba Bakarr3，WU Jiantao2，LIU Xue4，XIONG Li3#br#
(1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering，Hohai University，Nanjing，Jiangsu 210098，China；2. Highway and Railway Research Institute，Hohai University，Nanjing，Jiangsu 210098，China；3. Geotechnical Research Institute，Hohai University，Nanjing，Jiangsu 210098，China；4. Zhongrong Planning and Design Co.，Ltd. Guangzhou Branch，Guangzhou，Guangdong 510000，China)
Abstract：Corrosion of steel bolts is a potential safety hazard in anchorage structure engineering. GFRP bolt has become one of the solutions because of its corrosion resistance and high strength. In order to study the durability of GFRP anchor structure，a stress relaxation experimental device for FRP anchor structure was developed，and three groups of experiments were performed to study the stress relaxation characteristics of pre-stressed GFRP anchor structure under the combination of corrosive environment and load. The evolution curves of stress and strain of the anchor structure were obtained and the effects of corrosive environment and load on the stress relaxation of pre-stressed GFRP anchor structure were analyzed. The results show that the developed experimental device can efficiently set up environmental impact conditions and capture the combination effect of corrosive environment and load conditions. The stress relaxation of GFRP anchor structure is affected by the environment and the stress，and the environment has greater influence. Most of the stress relaxation occurs in the early stage after loading. Stress relaxation of GFRP anchor structure mainly comes from bond degradation of the anchorage section，and partly from elastic modulus decrease of the bolt body. Compared with alkaline environment，the degradation rate of interface bond state of anchorage section in distilled water environment is higher. It is difficult to ensure the synchronization of deformation of GFRP bar and grating sensor by bonding coupling under long-term solution corrosion.
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2020, Vol. 39 
