Performance Enhancement of Reinforced Concrete One-Way Slabs With Maximum-Moment Openings Using CFRP Strengthening Techniques: Experimental and Numerical Analysis

Numerical finite element (FE) models of reinforced concrete (RC) oneway slabs with maximum moment openings were developed in this study. Six slab specimens were tested in the laboratory: two served as control slabs, while four were strengthened using externally bonded carbon fiber-reinforced polymer (CFRP) laminates and near-surface-mounted (NSM) CFRP rebars. The laboratory results, including load-deflection response, crack patterns, and failure modes, were used to validate six numerical models created using ABAQUS software. The numerical findings showed good agreement with the experimental results, with the ratio of laboratory ultimate load to numerical ultimate load ranging from 0.91 to 1.22. The calibrated FE models were then used to investigate variables not covered in the laboratory tests, such as variations in opening width, concrete compressive strength, and the type and amount of CFRP strengthening. The results showed that the proposed equation, derived from numerical analysis and previous studies, accurately predicts the ultimate load for unstrengthened one-way slabs with various opening sizes. The numerical analysis also indicated that higher concrete compressive strength significantly enhanced the ultimate load in strengthened slabs with openings by up to 71.73%. Additionally, increasing CFRP reinforcement on the tension side increased the load capacity by up to 74.71% and altered the failure modes.