配置500 MPa钢筋的混凝土梁裂缝试验研究

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

摘要:

为研究配置500 MPa纵向热轧带肋钢筋的混凝土梁的裂缝特征及评估相关规范裂缝计算公式的适用性,进行了22根钢筋混凝土梁受弯性能试验,得到22个平均裂缝间距和92组裂缝宽度数据,相应的钢筋应力范围在201~482 MPa,这些试验数据可反映钢筋应力较高情况下受弯构件的裂缝开展特点.试验结果表明,按规范GB50010—2002公式计算的平均裂缝间距、平均裂缝宽度和最大裂缝宽度比试验值普遍偏大,二者之比的均值分别为1.127,1.557和1.535.根据试验结果,提出配置500 MPa带肋钢筋的混凝土梁的裂缝宽度计算公式修正建议,并给出梁侧面钢筋处和受拉边缘的平均裂缝宽度的换算关系式,建议公式的计算值和试验值符合较好.

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.