Experimental Study On The Effect Of Dry And Wet Cycles On The Bonding Properties Of CFRP And Concrete

Carbon Fiber Reinforced Polymer(CFRP)is widely used in the field of engineering structure reinforcement because of its low density,high strength,good fatigue resistance,convenient construction and good appearance after reinforcement.A large number of engineering practices have shown that the durability of CFRP-reinforced concrete structures depends to a large extent on the durability of CFRP and concrete bonding properties.For coastal piers,highway bridges,reservoir gates in saline-alkali areas,bridge piers in water level change areas,etc.,they are subjected to salt solution soaking and dry-wet cycles for a long time,and the aging speed of the structure is fast,which is not designed.The base year of the project is often used to reinforce such buildings with CFRP.Based on this background,the single-sided shear test was used to test the bonding properties of CFRP and concrete with the factors of erosion environment,dry-wet cycle system and age.The dry and wet cycle and salt solution soaking environment were studied for CFRP.The effect of bonding properties with concrete.The results of the experimental study indicate that:(1)The effects of different factors on the failure modes and experimental phenomena were studied,and the main failure modes were CFRP and concrete peeling failure.(2)The effects of different factors on the peeling capacity of CFRP and concrete were studied.It is concluded that when the cycle time is short,different circulation systems have different effects on the stripping bearing capacity;when the cycle time is long,the stripping capacity of different circulation systems The impact is similar.(3)The transmission relationship between CFRP and concrete is studied.It is concluded that the strain transmission law is similar under different influencing factors,and the strain distribution shows that when the load level is low,only strain is generated within 20% of the distance from the loading end.The strain is transmitted from the loading end to the free end as the load increases.(4)Draw the bond-slip curve of the specimen after experiencing different factors.It is concluded that the characteristics and variation of the bond-slip curve under different influencing factors are: there are obvious fast ascending segments at the beginning,and the load increases.After a significant inflection point,enter a slow rise that is accompanied by fluctuations in the load.