Experimental Study On Bond-anchorage Properties Of HRBF500 Steel Bars In Concrete After High Temperature

Bond and anchorage is the most basic theory problem in reinforced concrete structure. In order to propel the implement of fine-grained high-strength steel in building structure, this paper did experimental research on the bond anchorage performance of HRBF500 (fine grain) reinforced concrete after high temperature.The main contents of this paper are as follows:1.On the basis of analyzing the influence factors of bond anchorage, this paper designed five parameters which includes concrete strength, temperature, yield strength of reinforcing bar, anchorage length and stirrups ratio. According to the changes of the five parameters above, experiments on eighty-one specimens are designed and completed, through which the paper got the load-slip curve and the average bond stress-slip curve of bond anchorage after high temperature. This paper also researched and analyzed the influencing regulations of various factors on the bond anchorage performance after high temperature.2.According to the experiment results, this paper researched and analyzed the relationship between the compression strength and bond strength after high temperature, it also got the variation rule of bond stress corresponding with the same sliding under different temperture, and comparatively analyzed theτ- s curves of different matrixes after high 3.Through statistical regression analyzing of experiment results, this paper deduced an accurate calculation formula for the bond strength of reinforced concrete after high temperature, which was verified also applied to ordinary high-strength reinforced.4.Based on the concepts and models in the concrete damage mechanics, this paper analyzed the deterioration situation of the adhesive property between HRBF500 steel bar and concrete after high temperature, established the interface damage model of the reinforced concrete, and deduced theτ- s constitutive equations which considers damages. Then it analyzed the interface damage mechanics and damage evolution mechanism after high temperature, and comparatively analyzed the development trend of interface damage after different temperature.5.This paper proposed the calculation formula for anchor length of high strength reinforced concrete after high temperature, which was proved with high reliability index through the analysis of reliabitly principle and method for bond anchorage.