Collision Safety and Life-Cycle Carbon Emission Assessment of GFRP Corrugated Beam Guardrails

Abstract

To evaluate the feasibility of glass fiber-reinforced polymer (GFRP) corrugated beam guardrails for low-carbon road safety facilities, this study compares GFRP and Q235 steel Class A W-beam guardrails in terms of collision safety and life-cycle carbon emissions. Vehicle–guardrail finite element models were established, and impact conditions of 5°, 10°, and 20° were considered. A life-cycle carbon emission assessment was conducted using 1 km of guardrail over a 50-year service period as the functional unit. The results show that the GFRP guardrail can contain and redirect the vehicle under all impact conditions. Under the standard 20° impact condition, its maximum lateral dynamic deflection is 660 mm and the vehicle exit angle is 10.7°, satisfying the selected Class A evaluation indicators. Compared with the Q235 steel guardrail, the peak resultant acceleration decreases from 178.5 m·s⁻² to 142.3 m·s⁻², a reduction of 20.3%. The life-cycle carbon emissions of the GFRP guardrail are 66,000 kg CO₂-eq·km⁻¹, which is 34.5% lower than those of the Q235 steel guardrail. Sensitivity analysis indicates that the GFRP material emission factor and cumulative maintenance replacement ratio are the dominant parameters.