Effect PCC Slab Curling and Warping on Pavement Roughness

Abstract

Longitudinal profile measurements are vital for assessing the functional performance in terms of smoothness for new and existing pavements. However, the longitudinal profiles of Jointed Concrete Pavements (JCP) are significantly affected by temporal and diurnal changes that influence curling and warping of the concrete slabs. Therefore, consideration of such effect is essential for accurate assessment of pavement smoothness. The longitudinal profile measurements are commonly summarized by the International Roughness Index (IRI) that reduces the thousands of elevation values into a single value. However, no matter which index is calculated from a longitudinal profile, the quality of the information is only as good as the profile measurement. Thus, there is a need to evaluate the impacts of temporal (seasonal temperature/moisture and daily temperature) variations on longitudinal profile measurements, especially for JCPs. In this study, a new method is proposed for separating the curvature related IRI (i.e., due to curling and warping) from the non-curvature related IRI (i.e., due to other distresses such as spalling, faulting, etc). The level of curling and warping within each profile was summarized in terms of the Pseudo Strain Gradient (PSG). Examples from a couple of JCP sections indicated that temporal variations during a single day could have significant impacts on IRI. Results show that diurnal variations in PSG explained many of the changes in roughness over time. Such influence of seasonal and daily IRI variations can influence current practices—how highway agencies collect surface roughness for pavement management purposes and perform smoothness measurements for construction quality control.