Prediction of differential drying shrinkage of airport concrete pavement slabs

In this study, strain gages were installed at the centre, edge, and corner of concrete pavement slabs of Incheon International Airport based on the slab depth, whereas thermometers were positioned at the slab centre to measure the slab behaviour according to the temperature change. A three-dimensional finite element model simulating the airport concrete pavement was generated, and the analysis was conducted by using the measured temperature and material properties as functions of the concrete age and slab depth as its input variables. The difference between the measured strain and predicted thermal strain was calculated as the drying shrinkage because the finite element analysis did not consider the moisture evaporation but rather only the temperature change. The calculated drying shrinkage was large near the top of the slab from where the moisture evaporated, and the differential drying shrinkage between the top and bottom of the slab increased until the concrete age of nearly one month. Consequently, an upward curling developed owing to the differential drying shrinkage. The upward curling was the most obvious at the slab corner because the position was more exposed to ambient air and less constrained than at other positions.