Title:
Shear Behavior of Lightweight Concrete Beams without Stirrups: Influence of Geometry, Reinforcement Type, and Fiber Bridging (Prepublished)
Author(s):
Ghassan Almasabha, Dania Al Ghazzawi, Haneen Wahbeh, Faris Alkhawaldeh
Publication:
Structural Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
crack width; dowel action; lightweight concrete; shear; size effect; steel fiber-reinforced concrete
DOI:
10.14359/51751921
Date:
8/14/2026
Abstract:
This study investigates the shear behavior of 141 lightweight concrete (LWC) beams without stirrups that were tested and reported in the literature. The specimens had different types of reinforcement (such as basalt fiber-reinforced polymer, carbon fiber-reinforced polymer, glass fiber-reinforced polymer, steel reinforcement) and types of fiber inclusion (basalt fiber, glass fiber, polypropylene fibers, steel fiber). The test results demonstrated that the main governing parameter is the shear-span-to-effective depth ratio, a/d, whereby the beams with a/d ≤ 2.5 exhibited higher shear strength. Beams with a/d ≥ 3.0 exhibited flexure-dominated behavior and brittle shear failure. Increasing the longitudinal reinforcement ratio in the range of 0.5 to 2.5% enhanced the experimental shear strength owing to a reduction in crack widths and an increase in stiffness. Steel-reinforced beams outperformed fiber-reinforced polymer-reinforced beams due to the higher stiffness of steel. Fibers had a beneficial effect on shear performance; steel fibers enhanced the shear strength by up to 125%, whereas glass fiber and basalt fiber resulted in moderate improvements in the concrete shear capacity, and polypropylene fibers primarily increased the ductility. Consequently, the shear behavior in lightweight concrete beams is controlled by geometry, reinforcement ratio, stiffness, and fiber bridging.