The College of Engineering at the University of Baghdad held a public defense for Master’s student Thar Mohammed Hamed from the Department of Civil Engineering for his thesis titled:
“Shear Strength of Concrete Beams Reinforced with GFRP Bars with Different Reinforcement Ratios.”
The defense took place on February 26, 2025, in Prof. Dr. Khaled Shaker Hall, under the supervision of Prof. Dr. AbdulMuttalib Issa Said.
Research Overview
The study explored the performance of Glass Fiber Reinforced Polymer (GFRP) bars in concrete beams, particularly for structures exposed to water, magnetic fields, electric fields, and other environmental challenges. The research aimed to:
- Assess shear resistance by analyzing the impact of varying GFRP longitudinal reinforcement ratios on load-carrying capacity, stiffness, crack control, and serviceability.
- Study crack behavior by evaluating crack width, crack spacing, and alignment with ACI 440.1R-15 serviceability limits.
- Compare GFRP and steel stirrups with different stirrup spacings (70 mm to 480 mm) to analyze their effect on shear strength, stiffness, and ultimate load capacity.
- Identify optimal reinforcement configurations for enhanced durability and sustainability while ensuring structural serviceability.
Experimental Methodology
- Strain gauges and LVDTs were used for precise deformation measurements.
- Digital Image Correlation (DIC) was employed to track crack propagation under incremental loads.
- A crack measuring camera recorded crack width at each load stage.
Key Findings and Recommendations
- Higher reinforcement ratios improve strength, stiffness, and crack control, but exceeding 1.35 leads to reduced load-carrying capacity due to bond limitations, as indicated by horizontal cracks.
- GFRP stirrups, when properly designed, offer comparable structural performance to steel stirrups for narrow stirrup spacings (70 mm to 125 mm), making them a viable alternative for corrosion-resistant applications.
Thesis Outcome
After the scientific discussion and evaluation by the examination committee, Thar Mohammed Hamed was awarded a Master of Science degree in Civil Engineering (Structural Engineering).
