Instrumentation and Evaluation of Prestressed Pavement
PennDOT sponsored a research project to monitor the performance of prestressed concrete pavement for pavement length changes, pre-stressing levels as a function of distances from slab ends, and load-stress response. A 3.2-km section of prestressed pavement was constructed along a section of US 220 in Blair County, Pa. The pavement is composed of 60 slabs, each 7.3 m wide and 178 mm thick. Active joints are spaced at 122 m.
CTLGroup developed an instrumentation program to monitor short- and long-term performance as well as to collect data during load testing of the pavement. The firm also performed material property testing of the concrete. The 110-count sensor array included Carlson strain gages, CTLGroup-developed concrete sister bar strain gages, concrete surface strain gages and thermocouples. Data were collected using remote data acquisition systems placed along the road shoulder.
This program has provided verification that prestressed concrete pavements are viable pavement alternatives. The thinner prestressed pavements are promising candidates for unbonded concrete overlays for projects in which grade constraints may not allow thicker conventional jointed concrete pavements.