THE APPLICATION AND VALIDATION OF AN ANALYTICAL METHOD IN THE STRUCTURAL REHABILITATION OF A CRACKED RIGID PAVEMENT

The use of high alkali cement together with aggregates rich in silica to build a jointed, unreinforced concrete pavement without dowels resulted in a chemical reaction causing microscopic cracking. This cracking reduced the stiffness of the slab and the strength of the subbase so that structural cracking developed under traffic loading. Visual assessment of the structural condition of the pavement was based on a load transfer constant which, in turn, correlated with deflections and relative vertical movements at the joints. To relate the visual condition to pavement response and, eventually, to performance, an analytical model was used to calculate pavement response in terms of vertical movement and deflections. Experimental overlay sections using PCC, continuously graded crushed stone, and asphaltic concrete, were built to calibrate the analytical model, and these sections were trafficked by road users; a mobile accelerated traffic simulator was also used to evaluate the relative performance of each section. This paper discusses the findings on some of the concrete overlay sections and data is extrapolated to include preliminary predictions of the performance of those overlays not yet tested by the traffic simulator.