The College of Engineering at the University of Baghdad held a public discussion of the MSc thesis submitted by Mustafa Abbas Shalkam from the Department of Civil Engineering, entitled “Performance of One-Way Fiber-Reinforced Concrete Slabs Reinforced with Hybrid GFRP and Steel Bars.” The discussion took place on Sunday, September 6, 2026, in the Prof. Dr. Khalid Shakir Hall, under the supervision of Prof. Dr. Ali Hussein Ali Al-Ahmad.

The thesis aimed to investigate the structural performance of one-way concrete slabs reinforced with a hybrid system of Glass Fiber-Reinforced Polymer (GFRP) bars and steel bars. It examined the effects of replacing different proportions of steel reinforcement with GFRP bars, as well as evaluating the influence of adding steel fibers on slab behavior in terms of cracking, ultimate load, deflection, stiffness, ductility, energy absorption, and failure modes.

The study included an experimental program involving eight concrete slabs measuring 2700 × 600 × 150 mm, divided into two groups: conventional concrete and concrete containing 1% steel fibers. The steel reinforcement was replaced with GFRP bars at ratios of 0%, 33.3%, 66.6%, and 100%. In addition, a numerical analysis was conducted using ABAQUS software, and the effects of increasing the steel fiber content to 1.5% and 2% were investigated.

The results showed that increasing the GFRP replacement ratio reduced stiffness and increased deflection, whereas partial replacement ratios improved ductility, energy absorption, and load-carrying capacity. The addition of steel fibers also enhanced crack control and crack propagation resistance, while increasing the slabs’ load-bearing capacity and energy absorption. However, complete replacement of steel bars with GFRP bars resulted in brittle failure due to the absence of yielding in the steel reinforcement.

Accordingly, the thesis presented several recommendations, including:

• Investigating the long-term behavior of slabs reinforced with hybrid GFRP and steel bars under sustained loading.
• Examining the effects of different environmental conditions on structural performance and the bond between reinforcement bars and concrete.
• Investigating the effects of different types and proportions of steel fibers and hybrid fibers on the structural behavior of concrete slabs.
• Conducting further studies under cyclic and dynamic loading, fatigue loading, and impact loading.

Following the scientific discussion, during which the examination committee listened to the researcher’s defense, addressed his responses to their questions, and evaluated the thesis, the committee decided to award the researcher a Master of Science degree in Civil Engineering / Structural Engineering.