| At present,there are a large number of reinforced concrete structures in service at home and abroad,but with the aging of materials and the improvement of safety requirements,reinforcement and transformation become urgent.Compared with the traditional reinforcement method,the carbon fiber reinforced composite material(CFRP)reinforcement method is widely used in the building reinforcement industry due to its high strength,light weight,and convenient construction.Due to the anisotropic material properties of CFRP,when it is subjected to impact,it is easy to cause its damage and may cause serious consequences that lead to structural collapse.Impact and explosion problems are the most common problems in life.However,in the current building reinforcement specifications,the impact damage of CFRP reinforced structures is still blank.Therefore,studying the impact resistance of CFRP reinforced square columns and the residual bearing capacity after impact damage has important practical value.This paper uses a self-developed drop hammer impact device to conduct low-speed impact tests on 14 CFRPreinforced square columns,and then uses a 500-ton four-column press to perform static load tests on the impact-damaged columns to study their residual bearing capacity.The research content and conclusions are as follows:1.The production and test setup of CFRP reinforcement column mainly introduces reinforcement material CFRP cloth,bonding agent E2500 S and E810 LS and so on.The equipment and test methods used in the two tests of impact and static load are introduced respectively.2.In the low-speed impact test,the impact location of the ram,the initial kinetic energy of the falling weight,and the number of CFRP reinforcement layers are used as parameter variables to perform low-speed impact on the CFRP-reinforced square column to obtain its failure form,and use a high-speed camera to record its failure process.The conclusions of data collation are as follows:(1)The damage to the edge is more serious than the damage to the face;(2)The greater the initial kinetic energy of the drop hammer,the greater the damage of the CFRP enclosure,and the more serious the damage to the reinforcement column;(3)The twolayer CFRP-reinforced column has less damage than the one-layer case,but the failure mode is similar.3.Static load test,the reinforced column after impact damage is statically loaded by a 500-ton four-column press in a displacement-controlled manner,and the force-displacement curve and strain are obtained while observing and recording the failure mode of the specimen during the loading process,And then analyze the impact of impact on the bearing capacity of the reinforced specimen under different basic variables.The final result shows that the damage column after impact damage is brittle failure in the static loading process,and impact damage is the direct cause of failure of the specimen. |
