EVALUATION OF THE CARRYING CAPACITY OF REINFORCED- CONCRETE SLABS SUBJECTED TO CONCENTRATED LOADS CLOSE TO THE SUPPORTS

The behaviour of reinforced-concrete (R/C) slabs subjected to concentrated loads close to their supports is investigated in this paper. An experimental program was carried out at Delft University of Technology on eighteen large-scale R/C slabs. After testing, three of the slabs were chosen as case studies. Nonlinear finite-element (NLFE) analyses were performed, and analytical models - either proposed by the standard codes or available in the literature – were used as well. The aim of the research is to compare the prediction of the carrying capacity of the slabs obtained through simplified analytical and numerical procedures, usable by analysts in the current design process. The research fits into a research program driven by the Dutch Ministry of Infrastructure and the Environment for the re-evaluation of the carrying capacity of existing bridges and viaducts, and of their components (beams and slabs), through the use of nonlinear FE analysis. The project provided the final publication of guidelines for nonlinear finite- element analyses to be followed by users in order to reduce modelling efforts and save time. The research well matches with the philosophy of the Model Code 2010 that offers different analytical and numerical calculation methods for the evaluation of the design shear resistance of R/C members according to different safety levels of approximation.