Characteristics of compressive stress around dowel joint in concrete pavement system

Abstract

Although Friberg’s theoretical analysis is frequently used to analyse the dowel bar-concrete interaction in jointed plain concrete pavement (JPCP) system, the compressive stress concentration at top and bottom of the dowel slot cannot be explained with this theory. In this paper, two modifications including the elastic deformation of concrete support and the stress distribution factor considering the sinusoidal contact stress distribution are proposed to improve the Friberg’s theoretical analysis. Modifications are then validated against elastic finite element analysis (FEA) results in terms of the contact stress distribution, the maximum compressive stress as well as the range of compression zone. To further investigate the maximum compressive stress at the joint surface, relevant parameters including the dowel bar diameter, the modulus of elasticity of concrete as well as the joint width are studied through elastic finite element analysis (FEA). Apart from proposing referenced moduli of dowel support, a close relationship between the modified modulus of dowel support and dowel bar diameter is also found and verified. Finally, differences between the Friberg’s theoretical analysis and the modified method are summarised in a flow chart at the end of the paper.