Structural Assessment of the Effect of a Cement-Stabilized Base Combined with a Cold Central-Plant Recycled Layer at the NCAT Test Track

Abstract

Two full-scale pavement sections built in 2012 at the National Center for Asphalt Technology (NCAT) Test Track were used to assess the effectiveness of combining a cement-stabilized base and a cold central plant recycled (CCPR) layer, from the perspective of the structural performance under accelerated traffic loading. The two sections had similar asphalt concrete (AC) layers over CCPR while one was built over an aggregate base and the other was built over a cement-stabilized base resulting from a full-depth reclamation (FDR) process. The two test sections performed adequately, presenting no evidence of pavement damage during a two-year period (10 million ESALs) of accelerated traffic loading. Furthermore, ride quality was not significantly affected with the application of traffic. Frequent deflection testing over the duration of the study revealed that the section over the cement-stabilized base exhibited much less temperature sensitivity and higher moduli when compared to the section over the aggregate base. Similarly, based on stress and strain measurements performed over the duration of the experiment, it was inferred that the cement-stabilized base layer appears to cure over time, limiting the strain levels and improving the structure over time.