Experimental Research On The Bend Behavior Of HRB400 Reinforced Concrete Beams

HRB400 steel bars is characterized by high ratio between strength and price, stable quality, good welding quality and ductility. At present ,it has been listed in revised newly code for design. It must be widely used as leading steel bar in reinforced concrete structure of china. But the sudy in the crack width and deflection of HRB400 Reinforced Concrete Members under the state of service ability is deficiency. So it is necessary to make a research about these aspects.Based on the experiment of 7 HRB400 Reinforced Concrete Beams and 2 HRB335 Reinforced Concrete Beams, the testing results and calculation results using the code formula of bearing capacity of the HRB400 Reinforced Concrete Beams are compared. The difference of crack width under the state of service ability of the HRB400 steel bars reinforced concrete beams and the HRB335 steel bars reinforced concrete beams with the same bearing capacity is analyzed. Whether the HRB400 steel bars reinforced concrete beams can be met the limit of the maximum crack width and the limit of deflection is discussed. According to the test of 9 beams, the influence of the ratio of bar diameter and the ratio of longitudinal reinforcement and convering layer on mean crack internal of the HRB400 steel bars reinforced concrete beams is studied. The testing results is compared with calculation results using the code formula. Based on the different code formulas and experiment data, this paper suggests a formula that can calculate crack width and average crack interval of HRB400 steel bars reinforced concrete beams.This paper found finite element model to stimulate the testing process. This paper also compares the testing results with finite element analysis results.