Continued monitoring of instrumented pavement in Ohio

"December 2002."; Final report.; Performed by Dept. of Civil Engineering, Ohio University in cooperation with the Federal Highway Administration for Ohio Dept. of Transportation under state job no.; Harvested from the web on 12/19/05Performance and environmental data continued to be monitored throughout this study on the Ohio SHRP Test Road. Response testing included three new series of controlled vehicle tests and two sets of nondestructive tests. Cracking in two SPS-2 sections with lean concrete base confirmed observations elsewhere that PCC pavement may not perform well when placed on rigid base. Of the five types of base material used on LOG 33 and evaluated for their effect on AC pavement performance, deflection measurements on the asphalt treated base fluctuated most with changes in temperature. None of the other bases were sensitive to temperature. Cement treated base had the lowest deflection. On unbound material, bases containing large size stone gave the lowest deflection. The preponderance of data collected in the laboratory and at the ERI/LOR 2 site suggests that PCC pavement performs poorly on 307 NJ and CTFD bases. All sections with 25-foot slabs, except those with ATFD base, and the section with 13-foot slabs on 307 NJ base had significant transverse cracking. The 13-foot long slabs with 307 NJ base also had some longitudinal cracking. Considering the relatively short time these pavement sections had been in service, this level of performance was considered unacceptable. The ATFD base appeared to be performing best. On JAC/GAL 35, subgrade stiffness had a significant effect on dowel bar response. Looseness around dowel bars affected their ability to transfer load. Larger diameter and stiffer dowel bars provided better load transfer across PCC joints. The most effective dowel bar in these tests was the 1.5" diameter steel bar. The performance of 1" steel dowel bars were similar to 1.5" fiberglass bars. One-inch diameter fiberglass dowel bars were not recommended for PCC pavement. While undercutting PCC joint repairs initially reduced the forces in dowel bars, the effectiveness of the undercut diminished over time. Dowel bar forces were about the same in the Y and YU types of joint repairs after some time.Performance and environmental data continued to be monitored throughout this study on the Ohio SHRP Test Road. Response testing included three new series of controlled vehicle tests and two sets of nondestructive tests. Cracking in two SPS-2 sections with lean concrete base confirmed observations elsewhere that PCC pavement may not perform well when placed on rigid base. Of the five types of base material used on LOG 33 and evaluated for their effect on AC pavement performance, deflection measurements on the asphalt treated base fluctuated most with changes in temperature. None of the other bases were sensitive to temperature. Cement treated base had the lowest deflection. On unbound material, bases containing large size stone gave the lowest deflection. The preponderance of data collected in the laboratory and at the ERI/LOR 2 site suggests that PCC pavement performs poorly on 307 NJ and CTFD bases. All sections with 25-foot slabs, except those with ATFD base, and the section with 13-foot slabs on 307 NJ base had significant transverse cracking. The 13-foot long slabs with 307 NJ base also had some longitudinal cracking. Considering the relatively short time these pavement sections had been in service, this level of performance was considered unacceptable. The ATFD base appeared to be performing best. On JAC/GAL 35, subgrade stiffness had a significant effect on dowel bar response. Looseness around dowel bars affected their ability to transfer load. Larger diameter and stiffer dowel bars provided better load transfer across PCC joints. The most effective dowel bar in these tests was the 1.5" diameter steel bar. The performance of 1" steel dowel bars were similar to 1.5" fiberglass bars. One-inch diameter fiberglass dowel bars were not recommended for PCC pavement. While undercutting PCC joint repairs initially reduced the forces in dowel bars, the effectiveness of the undercut diminished over time. Dowel bar forces were about the same in the Y and YU types of joint repairs after some time