Glass-fiber-reinforced-polymer (GFRP) grating has found widespread use in several industry sectors due to its
durability, lightweightness, accessibility to installation, and low maintenance requirements. Its bidirectional
fiber strength provides exceptional corrosion resistance, high strength, and extended service life compared to
other types of fibers. This research introduces a novel embedded reinforcing system using GFRP grating to
improve the punching shear resistance of RC flat slabs. The results of seven specimens tested experimentally
under vertical static loading are displayed, taking into account the influence of the grating variables such as (1)
the effect of using the gratings; (2) the thickness of the gratings; (3) the position of the gratings through the slab
thickness; (4) the number of gratings through the slab thickness; and (5) the dimensions of the gratings, whereas
the concrete characteristic strength, steel yield strength, slab thickness, column dimensions, slab dimensions, and
steel reinforcement ratio were kept constant. Extensive instruments were used to record the test results, including
slab deflection, concrete strains, reinforcement steel strains, GFRP grating strains, crack and failure load, and
monitoring crack patterns and failure modes. Test results revealed an improvement in the failure load ranging
between 9.03 % and 27.67 % for the specimens strengthened by the proposed GFRP grating system as well as a
wider punching failure surface compared to specimens without gratings. In addition, a nonlinear finite element
analysis was carried out using the ANSYS program with correlational evaluation using load-deflection response
and cracking pattern, which resulted in a good convergence of numerical simulations and experimental performance
results ranging from 1.0 % to 8.0 %. Key parameters, namely the concrete compressive strength, steel
reinforcement yield strength, main steel reinforcement ratio, secondary steel reinforcement ratio, column dimensions,
slab thickness, concrete cover, and GFRP grating characteristics, were investigated through a parametric
study adopting Nonlinear Finite Element Analysis (NLFEA) by the ANSYS program, where the output
results were compared to the recent code provisions. |
