Lightweight Fiberglass Concrete Beams of Varying Steel Reinforcement and Shear-Span Depth Ratios

Ghoniem, Amr G.; Gamal, Mariam; Aboul Nour, Louay

doi:10.22059/ceij.2024.372257.2010

Lightweight Fiberglass Concrete Beams of Varying Steel Reinforcement and Shear-Span Depth Ratios

Articles in Press

Authors

¹ Lecturer, Structural Engineering Department, Faculty of Engineering, Zagazig University, 44519, Egypt

² Structural Engineering Department, Faculty of Engineering, Zagazig University, 44519, Egypt

10.22059/ceij.2024.372257.2010

Abstract

Fiberglass lightweight concrete combines the advantages of fiber usage in a lightweight concrete matrix. In the present study, 8% of the cement weight was replaced by silica fume. Six specimens containing 2% glass fiber and 75% coarse aggregate replaced with lightweight expanded clay were subjected to a 4-point bending test. The study examined how four shear-span depth ratios (1.5, 3.0, 3.57, and 4.5) and three reinforcement ratios (low, medium, and high) affected collapse performance. Among all low-reinforced samples, the 1.5 shear-span depth exhibited the greatest improvements in resistance, mid-span deflection, stiffness, energy absorption, fracture energy, and toughness, showcasing flexural compression collapse. In contrast, the 3.57 shear-span depth low-reinforced specimen achieved the highest ductility ratio. Compared with all other 3.57 ratio samples, the low-reinforcement sample exhibited mixed flexural-shear crack patterns and the highest ductility ratio, fracture energy, and capacity of energy absorption. However, the highly reinforced sample displayed an oblique shear collapse mode and the highest stiffness enhancement. Finally, the proposed model predicting the shear strength was conducted. So, engineers can adapt the structural role of the fiberglass lightweight concrete beams to meet specific project requirements.

Keywords