Different NSM FRP technique for strengthening of RC two-way slabs with low clear cover thickness


دانشگاه سمنان


An experimental program was carried out to investigate the effectiveness of a novel near surface mounted (NSM) technique using innovative manually made CFRP rods (MMRs) and manually made CFRP strips (MMSs) for flexural strengthening of reinforced concrete (RC) two-wayslabs with low clear cover thickness. Four full-scale RC slabs (1500×1500×120 mm) were tested under monotonic four-point bending. One slab was kept un-strengthened as the control specimen, one slab was strengthened using NSM GFRP rods, and the other two slabs were strengthened using NSM CFRP MMRs and NSM CFRP MMSs. The load-deflection responses, strain measurements, and failure modes of the tested slabs were studied and discussed. The behavior of slabs strengthened with this technique was compared to the behavior of the slab strengthened with GFRP rods. The test results confirmed the feasibility and efficacy of this technique in improving the flexural behavior of RC two-way slabs. Strengthened slabs showed an increase in flexural capacity between 279 and 394% over the control specimen. A 3D nonlinear numerical model was developed using the finite element (FE) method to predict the flexural behavior of the tested slabs. A good agreement between experimental and numerical results was observed.