Papers by Haitham M . F . Mostafa
Frattura ed integrità strutturale, Feb 15, 2024
Structures, Feb 1, 2024
Glass-fiber-reinforced-polymer (GFRP) grating has found widespread use in several industry sector... more 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.
Fracture and Structural Integrity, Dec 16, 2023
Frattura ed Integrità Strutturale, 2024
The literature review showed insufficient relevant research on the application of Glass-Fiber-Rei... more The literature review showed insufficient relevant research on the application of Glass-Fiber-Reinforced-Polymers (GFRP) gratings in the structural elements, while GFRP bars, laminate, sheets, and strips, have been extensively explored. This research aims to present a proposal for a new reinforcing system using GFRP gratings to improve the punching shear resistance of RC flat slabs. Results of seven specimens tested experimentally under vertical static loading are displayed, taking into account the influence of the gratings variables. Test results revealed an improvement in the ultimate load ranging between 9.03% and 27.67% for the specimens strengthened by the proposed GFRP grating system. A Nonlinear Finite Element Analysis (NLFEA) 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 gratings characteristics, were investigated through a parametric study adopting NLFEA by the ANSYS program, where the output results were compared to the recent code provisions.
Frattura ed Integrità Strutturale, 2024
A thorough study of the literature indicated that there is not much relevant research on the appl... more A thorough study of the literature indicated that there is not much relevant research on the application of GFRP gratings. Otherwise, extensive study has been done on FRP bars, laminates, sheets, strips, and rods. This study proposes a novel approach to improve the punching shear resistance of flat slab column connections by inserting GFRP gratings across the slab thickness. The results of seven specimens tested under vertical static loading are presented, considering the influence of the grating’s characteristics. All specimens were tested as simply supported slabs under one point of static loading. Experimental results, including crack patterns, slab deflection, concrete compressive strain, tensile steel strain, GFRP grating strain, and failure load, were recorded using extensive electric instrumentation. Test results revealed an enhancement in the failure load ranging between 9.03% and 27.67% for the specimens provided with the GFRP grating. In addition, a nonlinear finite element numerical model analysis was carried out using the ANSYS 15 program. Correlational studies based on the load-deflection response and crack patterns were utilized, resulting in a good agreement between numerical simulations and experimental results with differences ranging from 1.0% to 8.0%.
Structures, 2024
Glass-fiber-reinforced-polymer (GFRP) grating has found widespread use in several industry sector... more 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.
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Papers by Haitham M . F . Mostafa