Behavior of GFRP HPC- Columns Exposed to Axial Load and Elevated Temperature

Helal, Ahmed Mohammed; El-Sayed, Taha A.; Shaheen, Yousry B.

doi:10.21608/erjsh.2025.381617.1419

Behavior of GFRP HPC- Columns Exposed to Axial Load and Elevated Temperature

Document Type : Research articles

Authors

¹ Civil Engineering Department, Faculty of Engineering at Shoubra, Benha University, Cairo, Egypt

² Civil Engineering Department, Faculty of Engineering, Menoufia University, Menoufia, Egypt

10.21608/erjsh.2025.381617.1419

Abstract

This study examines the combined impact of axial load and elevated temperature (up to 300 °C) on concrete columns reinforced by GFRP. The study suggests an economical and accurate method for evaluating the fire resistance of these columns under external load and elevated temperatures. The experiment was conducted on 8 samples casted from normal and high-strength concrete. The normal concrete has a 30 MPa strength and a water-cement ratio of 42% , while the high-strength concrete has a strength of 60MPa and a water to cement ratio of 25%, and a silica fume ratio of 15%. The tested concrete column samples have dimensions of 150 mm in depth, 150 mm in breadth and 1500 mm in height. The laboratory experiment was conducted and the column was subjected to axial load while the column was exposed to elevated temperature (300 ℃). The study variables included concrete strength and the sequence of thermal and mechanical loading (before, during, or after heating(. Although previous studies examined either the thermal degradation of GFRP bars or the structural performance of concrete columns under fire, few studies combined both aspects under realistic loading conditions. The findings indicate that GFRP-reinforced columns experience noticeable reductions in load capacity and ductility under elevated temperatures, particularly when heating occurs before loading. High-strength concrete columns showed better residual strength and deformation control than normal-strength ones

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