Experimental and numerical behavior of strengthened reinforced concrete slabs

In terms of the importance of establishing mega structures in Egypt, there is an increasing demand to strengthen their slabs. Accordingly, this research was initiated with the objective of assessing different strengthening techniques (strengthening by concrete jacket or strips of carbon fiber reinforced polymer “CFRP”), where a multi-disciplinary approach was employed. Principally, literature within the domain of slab strengthening was amassed and scrutinized. An experimental work was conducted to examine 5 specimens of slabs under 4-point loadings. Crack patterns, midspan deflections, and steel strains were designated, where load–deflection curves and load-strain curves were produced. Moreover, the experimental investigation was replicated numerically by ABAQUS. Experimental and numerical results were contrasted, from which it was apparent that their results provided comparable trends. Confident with this contrasting process, a parametric study was achieved by ABAQUS, where 54 specimens with various parameters were investigated. Results showed that strengthening with RC jacketing and CFRP strips enhanced the load capacity and initial stiffness while decreasing the ductility for RC slabs. In addition, various jacketing bar and CFRP properties changes showed significant enhancement in the behavior of strengthened slabs. The numerical results showed enhancement in the load capacity of strengthened specimens due to the increase in the jacketing yield strength, bar diameter, and the jacketing concrete compressive strength. Increasing the number of CFRP strips enhanced the performance of the strengthened slab specimens by 14.2% ~ 25.1%.