Evaluation of Rubblized Pavement Sections in Michigan

In 1987 the Michigan Department of Transportation (MDOT) began using rubblization of portland cement concrete (PCC) pavement followed by the application of a hot-mix asphalt (HMA) overlay as a rehabilitation method for deteriorated PCC pavements. Early projects constructed in Michigan used the resonant frequency breaker to rubblize the PCC pavement, but by 1997 MDOT began to use the multi-head breaker (MHB) also. In 1999, because some rubblization projects needed rehabilitation after fewer than 12 years of service, MDOT initiated a study to identify causes for underperforming rubblized concrete pavement projects. The current study, initiated in 2005, was conducted specifically to investigate the performance of rubblized projects constructed with the MHB with the use of data provided by MDOT. Analysis of projects constructed in Michigan that used the MHB between 1997 and 2002 revealed that 20 of the 21 pavement sections evaluated had a distress index (DI) condition rating of good, and all sections had ride quality index values in the excellent or good category. The international roughness index values also indicated that all pavements were in good condition, with values of less than 95 in./mi. The DI for most sections indicated that the distress was due to longitudinal cracking at the pavement construction joint and at the pavement edge. Most distresses present on the pavement sections seemed to be related to poor or insufficient drainage, overlay construction issues, or HMA mixture problems.