Prediction of Moisture Curling of Concrete Slabs for Airfield Applications: Fid-Bau Portal

Prediction of Moisture Curling of Concrete Slabs for Airfield Applications

Lange, D. A. / Lee, C. J. / Liu, Y.

Curling occurs due to a non-uniform gradient of internal temperature and relative humidity in concrete slabs on ground. The curled geometry and self-weight of the concrete slab induce an undesirable high stress region near the concrete surface. Therefore, alleviating the degree of curling is an important issue for pavement design, and a proper prediction scheme is essential in the design process. In this paper, a systematic procedure for the prediction of curling is presented. A set of material models for aging concrete were used in the prediction. The model set is composed of elastic-static, creep, hygrothermal (drying shrinkage), and thermal models. A three-dimensional finite element analysis code with the material model set was developed for the numerical simulation of curling behavior. A computer simulation of the curling of a single slab tested at National Airport Pavement Test Facility was performed with the measured temperature and internal relative humidity profiles. A series of laboratory experiments was conducted in order to provide the parameters for the material model set. The experiments included the measurement of mechanical properties, internal relative humidity, temperature, drying shrinkage and creep. The numerical simulation with the developed model set shows a good agreement with the test results in terms of lift-off displacements. The prediction scheme presented in this paper can be used as a useful tool for concrete pavement design.