Temperature Responses of Partially Restrained Airfield Rigid Pavement
Joint quality affects stresses and deflections, which result from gear and environmental loading, and, hence, short- and long-term performance of rigid pavements. More specifically, multiple researchers have shown that looseness of dowel bars greatly affects responses of Portland cement concrete (PCC) pavement and its performance due to the reduction in load-transfer efficiency. Aware of the relevance of joint efficiency, researchers have used multiple approaches to include it in analyses: closed-form solutions, finite element (FE) analysis, and response from pavement instrumentation. This study combines the three approaches to consider the effect of joint continuity on temperature responses of airfield rigid pavement. Curling and blowup analysis was performed on airfield rigid pavement, considering generalized boundary conditions. The analysis combined closed-form solutions, FE methods, and pavement instrumentation. Closed-form solutions were derived for the curling responses and stability analysis (i.e., pavement blowup) for a slab-on-grade pavement with partially restrained edges. The closedform solutions were verified using the FE method. Furthermore, an FE model validated with experimental measurements was used to study the influence of joint condition on the responses to temperature of a multilayer airfield rigid pavement. In general, curling responses and blowup load are significantly affected by the continuity along a slab’s edges. Joint condition is more relevant for short slabs, and that aspect ratio is relevant when there is good continuity among slabs. Although conventional analysis does not consider a slab’s rotational continuity along the joints, this variable is more relevant than continuity of vertical displacement. Finally, the relevance of rotational continuity increases as the capacity to transfer vertical displacement increases.
DOT/FAA/TC-21/31 Authors: Al-Qadi, I.L. and Hernandez, J.