Numerical Analysis of the Flexural Strength and Ductility of RC Beams Strengthened with Steel-Reinforced Grout (SRG) Composites

This research examines the flexural behavior and ductility of reinforced concrete beams strengthened with steel-reinforced grout (SRG) composites using a numerical modeling approach. Experimental results from nine SRG-strengthened beams, as reported in the literature, were used to validate the model. The validated model was applied in a comprehensive parametric study to explore how the number of SRG layers, flexural reinforcement ratio, and SRG end anchorage affect the flexural performance and ductility of the beams. The findings show that SRG provides an effective solution for strengthening under-reinforced beams, notably improving their load-carrying capacity and mid-span deflection. However, the technique has little effect on beams that already possess adequate reinforcement. To further analyze SRG's impact on the flexural capacity of RC beams, the numerical results were compared to predicted strength values obtained through the section analysis method. Both the ACI 549-4R13 and ACI 440.2R-08 design strain models were incorporated in the analysis. The findings revealed that, although ACI 440.2R-08 design strain model was not initially developed for SRG, it yielded more accurate results than ACI 549-4R13. As a result, until more design guidelines are developed, it is recommended to use the ACI 440.2R-08 provisions for predicting the flexural capacity of SRG-strengthened RC beams.