Modelling of differential shrinkage of pavement slabs Available to Purchase

Non-uniform moisture distribution through the depth of jointed concrete pavement causes greater shrinkage at the top of the slab than at the bottom. This kind of shrinkage behaviour induces warping and tensile stress in the top surface of the slab. The warping shape changes with concrete age. In this study, an instrumented concrete slab with vibrating wire strain gauges was constructed in the field to investigate strains in the slab. The coefficient of thermal expansion of concrete was tested in the laboratory, and the thermal and shrinkage strains were analysed from the testing data. Furthermore, shrinkage of the concrete slab was predicted via the ACI (American Concrete Institute) 209R-92 Code. Relevant correction factors for the ACI 209R-92 Code were determined by using simultaneous equations for different vertical positions. The shrinkage effects on the pavement slab were converted to thermal effects and the differential shrinkage–equivalent temperature difference (DSETD) was used to quantify the effects of shrinkage on the behaviour of the concrete pavement. A fairly good correlation occurred between the results obtained from the DSETD model and the field test.