Experimental Study On Durability Of Bond Strength In FRP Single-laps And FRP-Steel Structure

Compared with traditional strengthening concrete and steel techniques,the technique of strengthening concrete and steel with FRP(carbon fiber reinforced polymer) has a lot of advantages;this technique will be applied to many fields of strengthening projects wildly.So there is an emergency to do some research on durability of FRP single-laps and FRP strengthened structure.In this paper,two topics are studied:(1) Durability of FRP single-laps.In this aspect,two different kinds of FRP(CFRP, GFRP),three different kinds of circulated environment(freeze-thermal,wet-thermal,wet-dry), three different kinds of load conditions(non-load,30%-failure-load,60%-failure-load) are considered to the influence of the bond performance.In freeze-thaw cycle environment, specimens are different in circle times of 50-times,100-times and 200-times.Parameter of wet-thermal environment is set as temperature:50℃,humidity:95%,and specimens are different in corrosion time of 30-days,60-days and 120-days.Wet-dry environment is held in salty water of 1.5%density,specimens are different in circulated times of 30-times,60-times and 120-times.Finally,a reason to this phenomenon is given,also a suggestion.(2) Durability of steel reinforced by CFRP.This part focus on wet-thermal environment (temperature:50℃,humidity:95%),specimens are different in corrosion time(15-days, 45-days and 90-days) and load conditions(non-load,30%-failure-load).Then give a conclusion to the affects of these factors.Finally,give a reason to this phenomenon,also a suggestion.