ACCELERATED LOAD TESTING OF FULL SCALE ASPHALT AND CONCRETE PAVEMENTS CONSTRUCTED OF CCPS

With support from the Ohio Coal Development Office, the USDOE's Combustion Byproducts Recycling Consortium, and the American Coal Ash Association, The Ohio State University embarked upon the accelerated load testing of full-scale pavement sections made of CCPs. Flexible (asphalt) and rigid (concrete) pavements were studied.

In this study, three concrete and three asphalt sections (one control and two CCP sections each) were constructed at the OSU/OU Accelerated Pavement Load Facility in Lancaster, Ohio. Class F fly ash and lime were used in the construction of the subgrade of all sections. Fly ash and bottom ash were incorporated into the construction of the base and subbase of the CCP sections of both the asphalt and concrete pavements. The CCP concrete slab included 30% and 50% replacement of cement with Class F fly ash. The instrumented pavements were constructed in summer of 2003. Instrumentation included pavement strain and displacement gauges, soil pressure and moisture gauges, pore water pressure transducers and environmental sampling ports. The control and CCP sections were subjected to accelerated load testing equivalent to 20 years of state highway traffic. The structural and environmental instrumentation pavement response was measured at regular intervals of loading.

Overall, the full-scale CCP pavement sections demonstrated similar or better performance and response to load than the control sections. At the end of the pavement design life, none of the asphalt sections had failed in terms of rutting or fatigue cracking. All three concrete sections demonstrated good performance and no fatigue cracking was observed in any of the concrete sections over the design life or even much later, i.e., at the end of the full-scale testing program. Both CCP base/subbase mixes out-performed the control mix based on the collected response, performance and FWD testing data throughout the whole full-scale testing program. During the second phase of the full-scale testing program, the two CCP sections showed better resistance to the adverse environmental conditions and exhibited better performance than the control section.