Experimental Study Of The RC Flexural Members Reinforced By Prestressed CFRP Plates At Both Ends Of The Anchorage

At present, China’s economy is in a period of rapid development. With therapid and sustainable development of the national economy and gradualimprovement of people’s living standards, people put forward higher requirementson the quality and functionality of various buildings. Because a large number ofbuildings constructed since the founding of new China are close to the end of servicelife, the buildings shall be reinforced and repaired so as to prolong the service lifeand improve the operation security; meanwhile, many new buildings may not meetthe requirements of normal use and affect the structural durability due to the designnegligence and construction errors that may occur in the construction phase, ornatural and man-made disasters that may appear in the service stage, so the buildingsmust also be reinforced and repaired. The traditional means of reinforcement havedifferent defects and limitations, so people gradually shift attention to the use of newcomposite materials on the reinforcement and repair of buildings in the past20years.The use of prestressed CFRP plates in the reinforcement of structural membersis a new direction in the reinforcement field in recent years. CFRP plates haveexcellent high-strength performance and durability, with broad application prospects.The prestress applied on CFRP plates by installing anchorage on both ends of thestructural elements can bring high-strength characteristics of CFRP plates into fullplay, can improve the mechanical properties of structural members in the servicestage, can improve the bearing capacity, and can prevent the debonding of CFRPplates and reduce the stress hysteresis.In this paper, combined with the Guangxi Natural Science Fund Project, thetests and researches were made on the concrete flexural members reinforced byprestressed CFRP plates, and the following aspects of research work were made:1. The CFRP plate wedge-type mechanical anchorage and its completetensioning system with engineering application values were developed to promote itsdevelopment towards engineering applications.2. Based on the anchorage for prestressed CFRP plates developed by theresearch group, six concrete beams with tensioned CFRP plates in the form of bonded and unbonded reinforcement were tested, the impact of different prestressesand spans on the flexural properties of reinforced beams was studied, and theultimate bearing capacity, cross-section strain, CFRP strain and midspan deflectionof the reinforced beams were studied.3. Based on the test results, the theoretical analyses of the concrete flexuralmembers reinforced by prestressed CFRP plate were made, the prestressing lossformula, bearing capacity formula, cracking load formula and deflection formula ofthe bonded and unbonded concrete flexural members reinforced by prestressedCFRP plates were given respectively. The calculated results agreed well with theexperimental results, which can provide references for future engineeringapplications.