Experimental and numerical study on multi-impact performance of pre-damaged beams strengthened with CFRP

Flexure Strengthening and Analysis Using CFRP Composite and Reactive Powder Concrete

“…Therefore, the calculated theoretical value will be significantly lower than the experimental value. The theoretical value obtained by the ultimate stress method is based on the assumption that the concrete cannot bear the tensile force and the CFRP patch has reached a subdued state, which is different from the phenomenon observed in the experiment, so the theoretical value obtained by the ultimate stress method will be higher [13]. Xiang et al [27] related study on the calculation method of flexural strength of damaged reinforced concrete beams strengthened by CFRP sheets, and the section analysis method was used to analyse the flexural strength of damaged beams.…”

“…Reinforcing with 2 cm thick RPC2 is also approximately equal to covering three layers of CFRP, showing that RPC-reinforced concrete can also obtain good reinforcement effect, as shown in Figure 5. When the CFRP-reinforced compression test specimen fails, it will produce brittle failure without warning, and with the increase of the number of reinforcement layers, the brittle failure of the test specimen is more obvious [11][12][13][14]. Therefore, this phenomenon should be avoided in the structural reinforcement design.…”

“…While RPC is used to strengthen the flexural specimen, it may be broken into two pieces, but RPC can exert excellent bond strength with the concrete matrix, so using RPC as a reinforced material for concrete components can indeed achieve reinforcement effects. When the CFRP-reinforced compression test specimen fails, it will produce brittle failure without warning, and with the increase of the number of reinforcement layers, the brittle failure of the test specimen is more obvious [11][12][13][14]. Therefore, this phenomenon should be avoided in the structural reinforcement design.…”

“…In recent decades, CFRP has been widely used in structural reinforcement, mainly because of its light weight, relatively ease of installation, high tensile strength, superior chemical properties, corrosion resistance, and fatigue performance, making it an attractive material in engineering structures [11][12][13][14]. In addition, RPC has also shown superior performance in structural reinforcement in recent years [15].…”

“…Generally, the reinforced concrete reinforcement method is commonly used to enlarge the column section to increase the bearing capacity, but the quality control of ordinary concrete reinforcement is not easy, and the large internal pores are prone to dry shrinkage and deformation, which reduces the effect of reinforcement and increases the column fracture. In addition, enlarging the section of the column will cause an unsightly appearance and inconvenience in space use [12,13]. Although there are many cases of CFRP and RPC in structural repair and reinforcement, there are not many related theoretical and experimental discussions.…”