Performance analysis of fiber reinforced recycled aggregate concrete at elevated temperatures using response surface
Muhammad Saqib Khan1, Muhammad Imran Khan2, Rafiq M Choudhry2
1National University of Sciences and Technology (NUST), Risalpur Campus, Risalpur, 24080, Pakistan.
Scientific Reports
|April 15, 2025
Summary
Recycled aggregate concrete (RAC) with 25% recycled content (RAC25) and steel fibers (SF) demonstrates excellent fire resistance and waste utilization. This sustainable material offers enhanced high-temperature performance for construction applications.
Area of Science:
- Materials Science
- Civil Engineering
- Sustainable Construction
Background:
- Growing fire risks and construction & demolition (C&D) waste necessitate sustainable building materials.
- Recycled aggregate concrete (RAC) offers a potential solution for waste utilization and improved material properties.
Purpose of the Study:
- To investigate the high-temperature performance of fiber-reinforced recycled aggregate concrete.
- To assess the potential of RAC as a sustainable, fire-resistant construction material.
Main Methods:
- Concrete mixtures with varying recycled aggregate content (0%, 25%, 50%) were tested at elevated temperatures (23°C, 300°C, 600°C).
- Steel fibers (SF) and polypropylene fibers (PPF) were incorporated into the most promising RAC mix (RAC25).
- Mechanical properties, including compressive and tensile strength, were evaluated. Statistical analysis using ANOVA and RSM was performed.
Main Results:
- RAC25 showed significantly improved strength retention at high temperatures compared to conventional concrete and RAC with higher recycled content.
- Steel fiber reinforcement (RAC25-SF) enhanced tensile strength and high-temperature performance, while polypropylene fibers (RAC25-PPF) showed limited benefits above 200°C.
- Fiber additions improved ductility, toughness, and moisture retention, effectively mitigating heat-induced cracking.
Conclusions:
- Recycled aggregate concrete (RAC25) reinforced with steel fibers is a viable, sustainable material for fire-resistant construction.
- This approach effectively addresses both fire safety concerns and the environmental challenge of C&D waste management.
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