Effects of Base Type on Modeling Long-Term Pavement Performance of Continuously Reinforced Concrete Sections

Abstract

Newer continuously reinforced concrete (CRC) pavements in South Dakota have exhibited undesirable levels of transverse cracking. This poor performance was not expected under the current recommended design practices. Long-term pavement performance (LTPP) CRC pavement data, previously analyzed by others, also could not account for the cracking. To seek an explanation, the original LTPP CRC data was reanalyzed with a more thorough approach. With multiple regression techniques on selected LTPP CRC data sets of comparable accuracy, consequential conclusions can be drawn once the base types are separated into subsets in the database. A similar model was developed for newer CRC pavements in South Dakota, and they showed the same response variables as the LTPP subset for granular bases. Significant correlation was found between cracks and steel depth, cracks and steel size, and cracks and pavement thickness, such that recommendations are made for South Dakota to decrease the steel depth and decrease the steel size and percentage. The nominal top size of the coarse aggregate was also found to be a significant contributor to crack width, with a shift from ³/4 in. to 1¹/2 in. resulting in a reduction in crack width and a much slower development of cracking over time.