PARAMETRIC STUDY OF SLAB-ON-GRADE PROBLEMS DUE TO INITIAL WARPING AND POINT LOADS

The repsonse behavior of rectangular slabs on grade is studied both experimentally and theoretically. A finite element model for slab-on-grade problems is introduced, where the concrete slab is represetned by 8-node brick elements, and the expansion joints and the subgrade are represented by boundary spring elements. To study the warping of the slab on grade, the subgrade boundary elements are taken to be nontension elements to represent the soil-resistant characteristics. The details of the study are described in which a general nonlinear analysis for the response behavior of slabs on grade was developed, field tests relevant to the warping floor slabs, and theoretical finite element results were compared with experimental measurements. Temperature effects, moisture gradients, slab thickness, modulus of subgrade reaction, and modulus of elasticity of concrete were studied, and an analytical parametric study was performed for edge and corner loadings of a typical floor slab.