Experimental Investigation Of Bond Performance Between Reinforcement And Concrete Simulate Subjected After Fire

Bonding power between the steel bar and the concrete ensures two different materials working together. Generally, when we do the reinforcement design of the fire construction, we neglected the damage of bonding power if the fire temperature is low. And we believed the bonding power loses completely and neglect the original steel bar and recalculated if the fire temperature is high. It is essential to carry out the experimental investigation of bonding power between steel bar and concrete after fire to improve the rationality and economy of reinforcement design of fired building.The test methods in this paper are as follows: heats the elements to the given temperature and keeps for a while to ensure the inside and outside temperatures of components are consistent, cools the components to natural ambient temperature, then accurately measures the instantaneous pull of the specimen and the corresponding slip amount at different temperatures by the "center pull-out test piece" test.On the basis of the test, this paper do some studies as follows:Through regression analysis of test data, this paper obtains the steel bar and the concrete cementing power model under different temperatures represent by continuous curve equation. It defines the concept of the bond stress temperature reduction coefficient, and it gives the relationship between bond stress temperature reduction coefficient and temperature. Then it studies the calculating method of bending members' ultimate bearing capacity after high-temperature. This paper revises the original basic assumptions, and advices that judges by calculating the damage form of reinforced concrete after fire before the original calculation method.Compare the conclusions of previous studies; this paper verifies the rationality and validity. This conclusion can be used as damage assessment of reinforced concrete structure after fire, strengthening design and the basis of entire process analysis of nonlinear finite element.