Effect of climate change and urban heat islands on the deterioration of concrete roads

Concrete pavements constitute a relatively small portion of US roadways but carry a disproportionately high volume of traffic. The potential deterioration in the long-term performance of these pavements due to climate change and the Urban Heat Island (UHI), however, has received little attention. To evaluate pavement performance, the present study considered thick and thin concrete pavements in the desert climate of Phoenix, AZ and the continental climate of Boston, MA using the Mechanistic-Empirical Pavement Design Guide (PavementME). To simulate potential climate change and UHI, the daily minimum and maximum air temperatures were uniformly and independently increased and the change in pavement damage as compared to the existing climate was evaluated. It was found that the change in damage had a strong, positive correlation with the change in Diurnal Temperature Range (DTR). This can be explained by the increase in concrete stresses due to combined applications of highly non-uniform temperature distributions through the slab and heavy truck loads. These stresses in turn affect the development of cracks in the pavement and hence its long-term performance. Additional variability in the DTR during each day of the service life further enhances this effect. It was found that increasing the thickness of concrete pavements actually leads to a greater sensitivity to change in DTR.