Numerical Evaluation of Moisture Warping and Stress in Concrete Pavement Slabs with Different Water-to-Cement Ratio and Thickness

Abstract

For better performance evaluation, it is of significance to investigate the factors affecting moisture distribution in concrete pavement slabs. This study provides methodology on both experimental measurement and numerical simulation of moisture distribution in concrete slabs with three water-to-cement (w/c) ratios of 0.3, 0.4, and 0.5. The effects of w/c ratio, slab thickness, and the environmental conditions on moisture distribution are evaluated in terms of the equivalent temperature difference, slab corner uplift, and the maximum tensile stress generated in concrete pavement slabs. A model is proposed for predicting the relative humidity profile along the slab depth. An equivalent temperature difference ΔTeq is used to quantify the moisture gradient effect. Greater ΔTeq is obtained in thin concrete slabs with high w/c ratio and when exposed to lower environmental relative humidity conditions. This renders concrete slab to excessive warping and tensile stress at the slab top surface when combined with traffic loadings. A thick slab with low w/c ratio possibly might reduce the warping deformation and the maximum tensile stress.