400MPa级钢筋混凝土轴拉构件裂缝宽度与钢筋应力关系试验研究

Experimental Study on the Relationship Between Crack Width and Reinforcement Stress of 400 MPa Grade Reinforced Concrete Axial Members

通过对400 MPa级钢筋混凝土轴向拉伸构件的试验,研究其裂缝宽度与钢筋应力的关系,为大体积混凝土裂缝控制提供技术支撑。试验量测了每级荷载下构件的开裂荷载、裂缝分布和间距、裂缝宽度等。结果表明:在裂缝条数稳定的情况下,平均裂缝宽度与钢筋应力大致成线性关系;将试验的裂缝宽度实测值与其相对应国标规范GB 50010—2010的平均裂缝宽度计算值相比,其均值为1.193、均方差为0.424,按95%的保证率试验的钢筋混凝土轴心受拉构件的短期裂缝宽度扩大系数为1.89。

The relationship between the crack width and the stress of steel bar had been studied through the test of 400 MPa grade reinforced concrete axial tensile members for providing technical support for the crack control of mass concrete.The test cracking load,crack distribu⁃tion and spacing,crack width had been investigated.The results indicate that the average crack width is roughly linear with the stress of the reinforcement under the condition of the crack number is stable.Comparing the actual measured crack width with the calculated value of the average crack width of the corresponding national standard GB 50010—2010,the average value is 1.193,and the mean square error is 0.424.The short⁃term crack width expansion factor of the reinforced concrete axial tensile specimen in the test is 1.89 with a 95%degree of confi⁃dence.