| FRP has many advantages (e.g. light weight, high strength, corrosion resistance,anti-fatigue, ect.), with the development of technology, in recent years FRP is widely used inthe field of reinforced concrete structures reinforced. But FRP reinforced concrete structurereinforcement effect and mechanism of interfacial debonding are so closely associated withthe FRP-concrete interface bonding properties, therefore, understand the FRP-concreteinterface bonding properties of the foundation reinforcement technology, but also the mostcritical part.In this paper, DIC new measurement system and double scissor combined direct pullouttest methods for CFRP reinforced concrete specimens were embedded in a monotonous staticload and fatigue load tests conducted studies and theoretical analysis, direct measurement ofthe specimen in the whole loading process and the audience response CFRP concrete slats,displacement distribution and analyzed along lath direction stress, strain distribution andfailure modes. The main contents of this article and the following conclusions:(1) Interfacial bond stress is not evenly distributed in the static load test, as the loadincreases, the peak of bond stress has a tendency of transfer to free end, while also increasingthe force transmission range; use the bond stress-interface slip of externally bonded CFRP toanalysis MSN model test, comparison of experimental results and theoretical models fordiscovery is also applicable to MSN model test.(2) Under fatigue loading test, by analyzing the strain distribution and load-sliphysteresis curve summarizes the interface failure law: a) Bonding adhesive layer appearedcracks in fatigue and rapid expansion to the concrete edge first in the early; b) Fatigue loadingcontinues to increase, adhesive layer cracks run through and CFRP-concrete Interfacialcrack started initiation, crack propagation form load end to free end; c) later in the fatigue,when bonded area cannot host a fatigue crack in ceiling loads quickly runs through specimenfailure.(3)Interfacial bond stress and bond stiffness increases the number of fatigue showedattenuation trend, based on existing theories proposed bond-slip envisaged under fatigueloading: use the bond-slip curves under static loading instead to outsourcing complex line ofhysteresis curve of bond-slip relationship under fatigue, bonded stress peaks after the fatigueload per level in constant decline and while loading and unloading through interface afterremnants of relative slip slip, when the residual slippage reaches the maximum slip interfacedamage. |
