Date of Defense
14-11-2024 8:00 PM
Location
F3-134
Document Type
Dissertation Defense
Degree Name
Doctor of Philosophy in Civil Engineering
College
COE
Department
Civil and Environmental Engineering
Keywords
Corrosion, beam, concrete, flexure, shear, repair, modeling.
Abstract
Advanced methods for rehabilitation of reinforced concrete (RC) beams with corroded reinforcement were designed and implemented in this research. The nonlinear flexural and shear behaviors of RC beams with corroded reinforcement repaired with fabric-reinforced matrix (FRM) composites were investigated. Numerical simulation models were developed to predict the flexural response of flexure-deficient continuous RC beams before and after repair with FRM composites. A novel sustainable repair solution that involves the use of cement-free geopolymeric matrix reinforced with nonmetallic fabrics was also introduced for rehabilitation of shear-critical RC beams with corroded stirrups. Simplified and easy-to-use analytical approaches were adopted to estimate the strength of the beams before and after repair with FRM composites. Laboratory tests were conducted to validate the modeling predictions. The experimental campaign related to the flexural behavior included testing of 15 continuous RC beams with corroded reinforcement of various severity of 10 to 40% cross-sectional loss in either the sagging or hogging region. Seven corroded beams were kept unrepaired, whereas seven corroded beams were repaired with carbon fabric-reinforced cementitious mortar (C-FRCM) composites. One virgin beam served as a benchmark. Test results showed that RC beams with 20–40% sagging corrosion exhibited a load capacity reduction of 9–15%, while those with hogging corrosion had a maximum reduction of 9%. The C-FRCM repair technique designed and implemented in this research successfully recovered the flexural performance of the virgin beam. The behavior of the flexure-critical continuous RC beams predicted numerically was in good agreement with that obtained from the experiments. The experimental campaign related to the shear behavior included testing of 10 shear-critical RC beam specimens with various levels of stirrup corrosion. Test variables included the level of corrosion damage in the stirrups, 15 and 50%, the type of the reinforcing fabrics, carbon (C) and polyparaphenylene benzobisoxazole (PBO), and the type of the matrix, geopolymeric andcementitious. A virgin uncorroded-unrepaired RC beam acted as a reference. The results showed that RC beams with 15 and 50% stirrup corrosion experienced respective shear strength reductions of 12 and 34%. The geopolymer-based FRM repair solution developed and implemented in this study was effective in restoring the original shear strength of the virgin beam, with a performance reaching 83–100% of that of the cement-based FRM repair solution. The analytical methodology adopted in the present study tended to provide reasonable conservative predictions for the flexural and shear strengths of the tested beams. The outcomes of this study would assist practitioners and researchers in proper design and implementation of innovative and sustainable solutions for rehabilitation of RC beams with corroded reinforcement.
Included in
STRUCTURAL BEHAVIOR OF CORRODED REINFORCED CONCRETE BEAM ELEMENTS REPAIRED WITH FABRIC-REINFORCED MATRIX COMPOSITES
F3-134
Advanced methods for rehabilitation of reinforced concrete (RC) beams with corroded reinforcement were designed and implemented in this research. The nonlinear flexural and shear behaviors of RC beams with corroded reinforcement repaired with fabric-reinforced matrix (FRM) composites were investigated. Numerical simulation models were developed to predict the flexural response of flexure-deficient continuous RC beams before and after repair with FRM composites. A novel sustainable repair solution that involves the use of cement-free geopolymeric matrix reinforced with nonmetallic fabrics was also introduced for rehabilitation of shear-critical RC beams with corroded stirrups. Simplified and easy-to-use analytical approaches were adopted to estimate the strength of the beams before and after repair with FRM composites. Laboratory tests were conducted to validate the modeling predictions. The experimental campaign related to the flexural behavior included testing of 15 continuous RC beams with corroded reinforcement of various severity of 10 to 40% cross-sectional loss in either the sagging or hogging region. Seven corroded beams were kept unrepaired, whereas seven corroded beams were repaired with carbon fabric-reinforced cementitious mortar (C-FRCM) composites. One virgin beam served as a benchmark. Test results showed that RC beams with 20–40% sagging corrosion exhibited a load capacity reduction of 9–15%, while those with hogging corrosion had a maximum reduction of 9%. The C-FRCM repair technique designed and implemented in this research successfully recovered the flexural performance of the virgin beam. The behavior of the flexure-critical continuous RC beams predicted numerically was in good agreement with that obtained from the experiments. The experimental campaign related to the shear behavior included testing of 10 shear-critical RC beam specimens with various levels of stirrup corrosion. Test variables included the level of corrosion damage in the stirrups, 15 and 50%, the type of the reinforcing fabrics, carbon (C) and polyparaphenylene benzobisoxazole (PBO), and the type of the matrix, geopolymeric andcementitious. A virgin uncorroded-unrepaired RC beam acted as a reference. The results showed that RC beams with 15 and 50% stirrup corrosion experienced respective shear strength reductions of 12 and 34%. The geopolymer-based FRM repair solution developed and implemented in this study was effective in restoring the original shear strength of the virgin beam, with a performance reaching 83–100% of that of the cement-based FRM repair solution. The analytical methodology adopted in the present study tended to provide reasonable conservative predictions for the flexural and shear strengths of the tested beams. The outcomes of this study would assist practitioners and researchers in proper design and implementation of innovative and sustainable solutions for rehabilitation of RC beams with corroded reinforcement.