连续配筋混凝土路面早期裂缝

Early crack of continuously reinforced concrete pavement

为了准确计算连续配筋混凝土路面早期裂缝的分布和发展规律,基于钢筋混凝土间粘结滑移的非线性本构关系,采用接触理论,建立了连续配筋混凝土路面在温度变化和混凝土干缩情况下的有限元刚度方程,得出了计算早期裂缝宽度和裂缝间距的有限元解。研究了混凝土抗拉强度、弹性模量的变化、施工季节、配筋率和钢筋直径等因素对连续配筋混凝土路面早期裂缝的影响。计算结果表明:混凝土抗拉强度与弹性模量随龄期的变化对连续配筋混凝土路面的早期裂缝在浇筑完成后28d内影响显著,随着龄期的增加逐渐趋于稳定,配筋率和配筋方式对早期裂缝的影响较大,为控制早期裂缝的发展,采用小直径多根数的配筋方式较为合理,且最好在秋季施工。

In order to accurately calculate the distribution and development laws of early crack for continuously reinforced concrete pavement （CRCP）, the nonlinear bond-slip relation between reinforced steel bar and concrete was analyzed, the finite element stiffness equation of CRCP was established by using contact theory under the circumstances of temperature change and dry shrinkage of concrete, the finite element solutions of crack width and crack space were obtained, and the effects of concrete tensile strength, elastic modulus change, construction season, reinforcement ratio and steel bar diameter on early crack were studied. Calculation result shows that the changes of concrete tensile strength and elastic modulus have a greater impact on early crack within 28 d after concrete pouring completion, the impact is gradually stable with the increase of concrete age; the reinforcement ratio and reinforcement mode also have a great impact off early crack, multiple-strand small-diameter reinforcement mode is more reasonable for the control of early crack, and it is better that construction season is autumn. 8 figs, 11 refs.