Proceedings on Engineering Sciences | 2026
Authors: Abdullah H.A.; Abed H.T.; Tais A.S.
DOI: 10.24874/PES08.01A.010
Journal: Proceedings on Engineering Sciences
Year: 2026
Publisher: Faculty of Engineering, University of Kragujevac
Document Type: Article
Open Access: All Open Access; Gold Open Access; Green Open Access
Cited by: 0
Flat reinforced-concrete (RC) slabs are widely adopted in modern construction due to their structural efficiency and architectural versatility, yet they remain susceptible to punching shear and flexural cracking. This study experimentally evaluates the rehabilitation of damaged RC flat slabs using externally bonded carbon and glass fibre-reinforced polymer (FRP) textiles. Six bidirectional RC panels measuring 500 × 500 × 50 mm were prepared with square and circular column supports and internally reinforced with 6 mm bars spaced at 80 mm. After 28 days of curing, specimens were strengthened with FRP composites bonded using Sikadur 330 epoxy and tested under single-point loading at a displacement rate of 1 mm/min. The concrete compressive strength averaged 40.5 MPa, exceeding Iraqi Specification IQS No. 5 (1984) limits. Strengthened specimens demonstrated a 20–25% increase in ultimate load capacity and reduced mid-span deflection compared to unstrengthened controls, with tape-oriented FRP configurations showing the most significant improvement. Panels supported by square columns consistently sustained higher loads than those with circular columns, indicating a pronounced interaction between column geometry and FRP configuration. These findings highlight that tailoring FRP type and fibre orientation to column shape enhances punching-shear resistance and extends the service life of RC slabs, providing a practical and cost-effective approach for rehabilitating ageing concrete structures while minimizing construction time and disruption. © 2026 Published by Faculty of Engineeringg.
Circular Columns; Fibre Reinforced Polymers FRPs; Load-Deflection Behaviour; Reinforced Concrete; Square Columns