Experimental Research Of Anchorage Properties For Fine-grained Steel Bars In Concrete

Fine-grained steel that is referred to as fine-grained hot-rolled steel bars, is a relatively new type of building steel which research and exploited in China. It is through the means of grain refinement to be a high strength, good toughness of the new steel.This text conducted two aspects of experimental studies:the material mechanics performance test of Fine-grained steel and the pull-out tests of Fine-grained steel in concrete.The material mechanics performance test shows, Intensity values fyk= 500 N/mm2, Elastic modulus Es=2.0×105N/mm2. In this International Standard, which satisfy certain requirement of ductility for earthquake resistant structure.In this paper, the effects of concrete strength, thickness of concrete cover, anchorage length, diameter and distribution of hoop of fine-grained bars for bond-anchorage properties have been analyzed comprehensively by 75 pull-out test. The result from pull-out test has been in good agreement with the value of calculation of the ultimate equation from the special study group of the "code for design of concrete structures" on bond-anchorage. The combin39 unit has been used in simulating the bond slip, the simulation results of the spring unit fit well with the bond-anchoring strength obtained from the pull-out test.Based on the experimental results, the thesis suggests aτ-s curve been fit for Fine-grained steel. The design of anchoring length through reliability analysis has been proposed. The result shows that the anchoring length for Fine-grained steel bar can be designed by the formula in existing "code for design of concrete structures" (GB50010-2002).The topic for the 863 plan to subsidize the subject (2007AA03Z550)...