Structural evaluation of rubblized concrete pavements in Iowa

Rubblization is one of the surface preparation techniques before placing a Hot Mix Asphalt (HMA) overlay that involves breaking the Portland Cement Concrete (PCC) pavement into pieces. This paper describes the structural assessment related to the long term performance of rubblized concrete pavements in Iowa. The structural performance of seven representative in-service rubblized concrete pavement sections across Iowa were evaluated through Falling Weight Deflectometer (FWD) and Dynamic Cone Penetrometer (DCP) tests, and visual pavement distress surveys. Through backcalculation of FWD deflection data using the Iowa State University (ISU) layer moduli backcalculation program, the pavement layer moduli values were determined and were correlated with the long-term pavement performance. The backcalculated subgrade modulus values were also compared with the subgrade modulus values obtained from DCP test results. The results indicate that the rubblized pavement sections in Iowa are performing very well. It is recommended that the rubblized pavements be frequently monitored to gain a better understanding of their long-term performance.