Experimental Research on Crack Spacing and Width of Reinforced Concrete Beams with 500 MPa Steel Bars

Abstract:

Twentytwo concrete beams reinforced with Grade HRB500 or HRBF500 longitudinal hot ribbed steel bars were tested to investigate their cracking characteristics and evaluate the formulas for crack spacing and crack width specified in the design code GB50010—2002.Twentytwo of average crack spacing dates and ninetytwo groups of crack width with the stresses of reinforcement at cracking sections ranging from 201 MPa to 482 MPa were obtained by these tests.The test results show that the values of average crack spacing,average crack width and maximum crack width which are predicted by the formulas of code GB50010—2002 are greater than the experimental ones in general and the average ratios of them are 1.127,1.557 and 1.535 respectively.Based on the test results,the modified formulas of crack width are put forward for the beams with 500 MPa hot ribbed steel bars,while the conversion formula of the crack width at the tension edge and the reinforcement center of beam side face is proposed.The proposed calculation formulas agree with the experimental results.