Longitudinal cracking at transverse joints caused by dowel bars in Jointed Concrete Pavements

Abstract

Longitudinal cracking at transverse joints in the Jointed Concrete Pavement (JCP) was investigated and causes were discovered by performing field observation and numerical analyses. Finite element models of JCP were developed considering very detailed modeling of dowel bars and their contact characteristic to concrete. Using the models, transverse stresses at joints that could induce longitudinal cracking were comprehensively analyzed. The results showed that primary causes of longitudinal cracks at joints were found to be related to the vertical translation of dowel bar and the curling of the JCP slab due to environmental loading. Other factors affecting those cracks included concrete elastic modulus, concrete thermal expansion coefficient, foundation stiffness, vertical temperature gradient, and bond characteristic between concrete and dowel bar. To mitigate longitudinal cracking at joints, dowel bars should be installed at the mid-depth of the slab and cares must be taken when installing dowel bars to prevent their vertical translation.