A Predictive Framework for Crack Width Assessment in GFRP-Reinforced Concrete Beams Using RSM

GFRP bars have been considered a major alternative to traditional steel reinforcement in recent years owing to their favorable mechanical properties. FRP longitudinal reinforcements have been used more frequently in civil engineering projects during the past few decades, mainly because concrete structures often face harsh environmental conditions. Research performed on FRP-reinforced concrete, particularly beams, has found that two key serviceability aspects, i.e., deflection and cracking, can differ significantly from those of steel-reinforced beams. Accordingly, reliable relationships to make accurate predictions for these parameters are necessary. Crack width is an important measure to evaluate the post-cracking behavior of RC beams. The tensile stress in the longitudinal bars transfers to the surrounding concrete by an increase in the flexural moment, leading to crack propagation. Since various factors affect the crack width in GFRP-reinforced concrete beams, this study proposes an accurate relation for predicting crack width using the response surface methodology (RSM). A more precise predictive model compared to existing ones is proposed by applying polynomial functions. To assess the accuracy of the proposed model, a dataset of experimental test results from previously published studies is used. Moreover, a sensitivity analysis is performed using the RSM approach to evaluate the effect of different design parameters. The obtained results show that the proposed relation offers higher accuracy than the existing models and provides a more dependable estimation of crack width.