Title: Premature Transverse Slab Cracking of Jointed Plain Concrete Pavement-Environmental and Traffic Effects

Author(s): W. Hansen, D. L. Smiley, Y. Peng, and E. a. Jensen

Publication: Symposium Paper

Volume: 206

Issue:

Appears on pages(s): 259-270

Keywords: built-in curling stress, concrete pavement, loss of slab support, truck loading

DOI: 10.14359/12257

Date: 4/1/2002

Abstract:
Top-down premature mid-slab transverse cracking was investigated for a jointed plain concrete pavement project with joint spacing of 4.88 m and located on I-96 in southeastern Michigan. The environmental (curling/warping) stresses were evaluated using conventional linear temperature gradient analysis (1) and a recent developed method for non-linear gradient analysis (2). Slab deflection profiles and temperature gradients for different times of day demonstrated that a built in upward slab curling was present, equivalent to a linear negative temperature gradient of 0.03 C/mm or greater. This condition increases curling stresses at mid-slab and outer edge during morning hour temperature conditions as the built in curling condition provides added negative thermal gradients. In addition, increased joint and corner uplift occurs, a condition, which favors loss of slab base support. For these conditions, finite element analysis for truck tandem axle loading at the edge of transverse joints predicts substantial increased slab deflection and top tensile stresses. Further, loss of contact moves the maximum tensile stress towards the mid slab region along the outer edge, where also curling stresses are highest. The combined tensile stresses were found to be significant and can initiate top down transverse cracking. Once surface cracks are initiated they tend to propagate inward and downward from repeated truck loading.