Experimental Research On Diagonal Crack Width Of Reinforced Concrete Beams With HRB500 Stirrups

HRB500 steel bars has the advantages of high strength,good ductility etc.This kind of steel bars has been widely used in reinforced concrete structure.When HRB500 steel bars was used as stirrup,the reinforced concrete beam may appear so oversized diagonal crack that it can't satisfy the engineering requirements for applicability and durability.So,the study on the diagonal crack problems of the high-strength stirrup concrete beams has important theoretical and practical significance.This test produced ten reinforced concrete beams with high-strength stirrups which are divided into two groups,and carried out the static test under the concentrated force:eight beams for the static test,two beams for the fatigue test.This has done the following work:1.This paper not only studies the development of diagonal crack,but also put emphasis on the different factors that affect the diagonal crack width.At the same time,combined with the gray theory,the main influencing factors and the important influencing factors were found.2.Based on the static load test results and the existing calculation theory,this paper gives the recommendation formula of diagonal cracking load and maximum diagonal crack width.It is found that the calculated results are in good agreement with the test results,which can be used to calculate approximately the cracking load and crack width.3.On the basis of fatigue test,this paper not only studies the shear crack development and stirrup stress change law of the reinforced concrete beams with high-strength stirrups,but also studies the effect of the stirrup ratio on the performance of the shear beams under the fatigue loads.