Abstract

This study investigates the performance of a case study reinforced concrete (RC) slab strengthened in flexure with Fibre Reinforced Polymer (FRP) sheets. The RC slab is at the top floor of a 17-storey building upon which three water tanks (of 1,000 l each) had to be built due to a change of use of the building's top floor. To assess the performance of the existing slab, site investigations and non-destructive testing (NDT) were carried out as per ACI 318 standards. To increase the load capacity of the slab, Externally Bonded Reinforcement (EBR) Carbon FRP sheets were bonded to the bottom of the RC slab. Following the strengthening intervention, the CFRP-strengthened slab was subjected to a 24-h load test (according to ACI 318) and to a Cyclic Load Test (following ACI 437) using an ad-hoc water pool built on top of the slab. The results from these tests (maximum and residual deflections of 0.92 mm and 0.34 mm, respectively) indicated that the CFRP-strengthened slab met satisfactorily the deflection criteria and performance indices of such tests. The CFRP-strengthened slab was then modelled and analysed in ANSYS® to calibrate and validate the experimental results. It is shown that the deflection and strains predicted by the finite element (FE) model match well the experimental measurements (errors < 15%), which confirms the suitability of the modelling approach adopted in ANSYS®. This article contributes towards the dissemination of real case studies of FRP-strengthened structures, which are scarce in the literature and thus can be useful to engineers and practitioners working in the field of structural strengthening.