Analysis and verification of stresses and strains and their relationship to failure in concrete pavements under heavy vehicle simulator loading

Research was performed to evaluate the behavior and performance of concrete pavement slabs at an early age under heavy vehicle simulator (HVS) loading. A concrete pavement test track was constructed at the accelerated pavement testing facility of the Florida Department of Transportation (FDOT). The test sections were instrumented with strain gauges and thermocouples to collect strain and temperature data. The finite element model FEACONS IV was used to analyze pavement behavior. Model parameters were determined by matching the deflection basins caused by the Falling Weight Deflectometer (FWD) load and the computed deflection basin, using FEACONS IV the finite element model. The measured maximum strains caused by a moving HVS wheel load were found to match fairly well with the measured maximum strains caused by a static wheel load of the same magnitude. The difference between static and dynamic strains for the same magnitude load was small and fluctuated between positive and negative values.; The FEACONS program was used to calculate the maximum stresses in each test slab due to the HVS loads at various times in this study. The applicable pavement parameters (effective modulus of subgrade reaction, joint stiffness, and edge stiffness), concrete elastic modulus, HVS load, and temperature differential in the concrete slab for each particular condition were used in each analysis. The computed stress-to-strength ratio can be used to explain the observed performance of the test slabs used in the slab-replacement study. The properties needed to ensure adequate performance of concrete pavement at early age were determined.; Impact echo tests were used successfully in this study to detect cracks in a concrete slab. This was manifested by a sudden drop in the apparent measured speed of P waves across the location of cracks. Cracks in the concrete slab were also successfully detected from observed changes in the measured strains from strain gauges that had been installed in the concrete.