水泥混凝土路面板湿度翘曲应力计算方法

为了分析湿度梯度对水泥混凝土路面力学性能的影响, 采用弹性力学的基本分析方法推导了非均匀无限水泥混凝土路面板在完全自由、轴向变形约束、弯曲变形约束、弯曲和轴向变形组合约束下的湿度翘曲应力计算公式, 利用弯矩等效原理, 推导了基于湿度翘曲应力的等效温度梯度公式, 基于连续配筋混凝土路面, 采用有限元法计算了非线性湿度分布情形下水泥稳定基层、粒料基层、沥青混凝土基层、沥青稳定基层、水泥土基层和自然土基层下的板顶和钢筋的应力与板的裂缝宽度。
研究结果表明: 湿度翘曲应力的大小取决于相对湿度的分布形式; 板顶应力随基层刚度的增大而增大, 当基层刚度从0.08 MPa·mm^-1增大到6.28 MPa·mm^-1时, 板顶应力从4.1 MPa增大到6.3 MPa; 基层类型几乎不影响钢筋的应力; 裂缝端部水平位移从板底至板顶逐渐增大, 大约从0.0 mm增大到2.9 mm。

Calculation method of moisture warping stress for cement concrete pavement slab

In order to analyze the impact of moisture gradient on mechanical properties of cement concrete pavement, the calculation formulas of moisture warping stress for nonhomogeneous infinite pavement slabs subjected to free-rein constrain, axial deformation constraint, bending deformation constraint, bending-axial deformation constraint were derived by using the basic analysis method of elasticity mechanics.The formula of equivalent temperature gradient based on the moisture warping stress was derived by using the equivalent principle of moment.Based on continuously reinforced concrete pavement(CRCP), the stresses and crack widths of concrete slab and steel stresses were computed by using the finite element method based on cement stabilized base, stable aggregate base, asphalt concrete base, asphalt stabilized base, limestone soil base and natural soil base.Research result shows that the magnitude of moisture warping stress depends on the relative humidity distribution; the surface stress at slab middle increaseswith the increase of base stiffness, when the stiffness of base increases from 0.08MPa·mm-1 to6.
28 MPa·mm-1, the surface stress increases from 4.1 MPa to 6.3 MPa; the type of base hardly has influence on the stress of steel; the horizontal displacement of crack end gradually increases from 0.0 mm to 2.9 mm from slab bottom to surface.