Effect of Pavement Support Condition on CRCP Behavior and Performance
Based on visual survey, dynamic cone penetrometer testing, and falling weight deflectometer testing on several continuous reinforced concrete pavement (CRCP) sections with or without distresses and high or low deflection, different support condition is the main cause of difference between CRCP behaviors and performances.
Currently, the support provided by the base layer under Portland cement concrete (PCC) pavement is most commonly characterized by elastic medium such as a spring constant. Analysis of PCC pavement behavior with a spring constant for pavement performance prediction has severe limitations, with the primary limitation being that base stiffness has little effect on the stresses and resulting performance in PCC pavement.
Field performance evaluations indicate a strong correlation between base support and PCC pavement performance. The uniformity of the base support also plays an important role in determining PCC pavement behavior and performance. This area hasn’t been investigated as thoroughly as warranted.
The prevailing distress mechanism in the Mechanistic Empirical Pavement Design Guide (MEPDG) developed under NCHRP 1-37(A) involves warping and curling stresses, which are alleviated with softer base materials. There is a discrepancy between the need for a strong base support for wheel load applications and weak base support for warping and curling stresses. In general, field performance evaluations show better performance in PCC pavement with a strong base support. Efforts should be made to determine the optimum base support.
It is expected that this research effort will provide useful information for pavement engineers and researchers to understand the effect of pavement support on CRCP behavior and performance and foundation to improve the durability of CRCP.
Author: Wujun Zhou, B.S.; M.S.E.