Effect of Panel Size and Radius of Relative Stiffness on Critical Stresses in Concrete Pavement

Design of concrete pavements is carried out with the help of available guidelines that are generally based on single size of slab panel. However, in practice, the slab size is seen to be different than the one recommended by most of the guidelines such as PCA (Thickness design for concrete highway and street pavements, Portland Cement Assosiation, Skokie, 1984) and IRC 58 (Guidelines for the design of plain jointed rigid pavements for highways, 4th Revision, Indian Road Congress, New Delhi, 2015) , especially on curves or at the junctions. It is also established that temperature stresses vary with the plan size of the panel. The important parameter in the design of concrete pavement is critical edge stress which depends on traffic and temperature load. However, it is observed that, for the same design parameters such as traffic load and subgrade stiffness of soil, critical stress values alter largely as the panel size is diverse from the standard one. The standard panel size as specified by PCA (1984) and IRC 58 (2015) is 3.5 m ×\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times $$\end{document} 4.5 m. In this paper, the effect of the size of slab panel and radius of relative stiffness on critical edge stress has been investigated. Analytical models have been developed to obtain critical edge stress for concrete pavement resting on an elastic soil foundation using finite element software. It has been found that, for smaller panel sizes with low radius of relative stiffness, critical stresses obtained are higher. Therefore, it is necessary to consider the effect of the size of slab panel and radius of relative stiffness, while designing the concrete pavement.