Work

Axial load–moment interaction diagram of full-scale hollow square columns reinforced with GFRP bars and ties

Year: 2026

Type: article

Abstract: The present study investigated the structural behavior of hollow square concrete columns reinforced with glass fiber-reinforced polymer (GFRP) bars and ties under eccentric loading. Eight columns with a square cross section of 400 x 400 mm and 2000 mm in height with a hollow core 150 mm in diameter were cast and tested. Four specimens were reinforced with steel bars and ties and the other four were reinforced with GFRP bars and ties. All the specimens had the same reinforcement ratio (1.6%). This study considered different test parameters such as reinforcement type (GFRP and steel), load eccentricity level (10%, 20%, 40%, and 80%), and the effect of hollowness. The test results indicate that the specimens reinforced with GFRP bars exhibited behavior similar to that of their steel reinforced counterparts under various levels of eccentricity. In addition, the eccentricity level had a greater effect on the behavior of the columns than did the reinforcement type. Increasing the eccentricity level from 10% to 20%, 40%, and 80% decreased the axial-load capacity by 15.3%, 52.5%, and 79%, respectively, for the GFRP-reinforced hollow columns. Similarly, the axial-load capacity of the steel-reinforced hollow columns decreased by 17%, 48.3%, and 81.9% as the eccentricity level increased from 10% to 20%, 40%, and 80%, respectively. The failure of the specimens tested under low eccentricity levels was compression controlled. In contrast, the specimens tested under high eccentricity experienced excessive lateral displacement, extensive cracking, and large GFRP-bar strains, indicating tension-controlled failure. Lastly, the failure envelope of the GFRP-reinforced specimens was marginally smaller than that of their steel-reinforced counterparts.

Source: Engineering Structures

DOI: 10.1016/j.engstruct.2026.122778

Authors: Amr Mahmoud, Salaheldin Mousa, Hamdy M. Mohamed, Brahim Benmokrane

Institutions: Université de Sherbrooke, Applied Science University

Language: English

Topic: Structural Behavior of Reinforced Concrete

Subfield: Building and Construction

Field: Engineering

Domain: Physical Sciences

SDG: Industry, innovation and infrastructure

Open Access status: hybrid

Estimated APC paid: $4,620