纤维增强磷石膏轴心受拉应力-应变曲线研究

Study on Axial Tensile Stress-strain Curve of Fiber-reinforced Phosphogypsum

为研究纤维增强磷石膏的受拉应力-应变曲线,将磷石膏粉、水泥、纤维的质量比设定为90%、10%及0.2%,以水灰比(0.7、0.8、0.9)为变化参数,制作了12个棱柱体试块。通过轴向单调拉伸试验,分析了纤维增强磷石膏的受拉应力-应变曲线、抗拉强度、峰值应变等力学指标。对归一化曲线进行拟合,给出了应力-应变曲线的数学表达式。研究表明,受拉应力-应变曲线呈非线性变化,且水灰比越低,曲线越陡峭;当水灰比从0.7增加至0.8及0.9时,轴心抗拉强度分别降低了11.4%及34.3%;峰值拉应变受水灰比影响较小,应变测量值位于31.5με~54.8με区间。

To study the tensile stress-strain curve of fiber-reinforced phosphogypsum,the mass ratio of phosphogypsum powder,cement and fiber was set at 90%,10%,and 0.2%,and 12 prism test samples were fabricated with the water-cement ratio(0.7,0.8,0.9)as the change parameters.Through the axial monotonic tensile test,the tensile stress-strain curve,tensile strength,peak strain,and other mechanical indexes of fiber-reinforced phosphogypsum were analyzed.The normalized curves were fitted,and the mathematical expression of the stress-strain curve was given.The research shows that the tensile stress-strain curves are nonlinear,and the lower the water-cement ratio is,the steeper the curve is;when the water-cement ratio increases from 0.7 to 0.8 and 0.9,the axial tensile strength decreases by 11.4%and 34.3%respectively;the peak tensile strain is less affected by the water-cement ratio,and the measured strain values are in the range of 31.5με~54.8με.