Fortifying flames: boosting concrete fire resistance with hybrid fiber polymers

ABSTRACT

This study investigates the thermal and mechanical properties of fiber-wrapped concrete specimens compared to a nominal mix without fibers, subjected to elevated temperatures of 250°C and 500°C over varying durations. Compressive and split tensile strengths were evaluated to assess the effectiveness of basalt, aramid, and hybrid (basalt + aramid) fiber configurations in enhancing concrete's resilience under thermal stress. Results indicate that fiber-wrapped samples consistently outperform the nominal mix in both compressive and split tensile strengths across all testing conditions. At 250°C, after 1 hour, compressive strengths ranged from 19.77 N/mm² (nominal mix) to 21.08 N/mm² (basalt + aramid strips), showcasing the protective role of fibers. Similarly, split tensile strengths at the same conditions varied from 2.03 N/mm² (nominal mix) to 3.11 N/mm² (basalt + aramid strips), highlighting significant improvements with fiber reinforcement. At 500°C, the nominal mix exhibited substantial strength degradation over time, whereas fiber-wrapped samples maintained higher strengths, particularly in hybrid configurations. These findings underscore the beneficial impact of fiber reinforcement in mitigating thermal-induced strength loss in concrete, suggesting practical applications in industries requiring fire-resistant structural materials.

Keywords:
Fiber-reinforced concrete; thermal properties; compressive strength; split tensile strength; elevated temperatures