Research On Reinforced Concrete Beam With High-Strength Stirrup Under Uniform Load

A new steel bar(HRB400)has been widely used in engineering structure ,after the Code for design of concrete structures(GB50010－2002)had been promulgated and implemented . Used HRB400 steel as stirrup, concrete beam may be appear oversized diagonal crack that cannot satisfy the engineering requirement for applicability and durability. All these required me to have a good research for the performance of the concrete beam with high-strength stirrup. Studying the appearance and development of the diagonal crack, the elements that affect the beam properties so as to deduce a calculated formula having an obvious theory principle has an important practice meaning. Based on the experiment studies of 8 concrete beams with high-strength stirrup, this paper not only discuss the load for crack and limitation, distribute tendency of the diagonal crack but also discuss the elements that affect the crack width, for example the distance between stirrup, the strength of concrete, the strength of steel bar, then this paper give out a calculated formula that can calculate diagonal crack width of concrete beam used high-strength stirrup bearing uniform load.This paper also calculated the practice diagonal crack width with different calculated formula, the results indicated that this formula suggested by this paper, could estimate the reality diagonal crack width properly.At last this paper summary the test result and give out a conclusion: the diagonal crack development tendency is similar to the concrete beams used ordinary strength stirrup under the condition that the beam with high-strength stirrup used ordinary strength concrete. If we can control stirrup ratio properly, structure used high-strength stirrup can satisfy the requirement of engineer.