Experimental study on the triaxial compression mechanical performance of basalt fiber-reinforced recycled aggregate concrete after exposure to high temperature

• DOI: 10.1016/j.cscm.2024.e03026
• Publication Date: 2024-03-05T08:26:38Z
• Authors: Xianggang Zhang; Youchuan Shen; Yuhui Fan; Xiang Gao
• Keywords: Basalt fiber; Triaxial compression; Mechanical performance; TA401-492; 0211 other engineering and technologies; Recycled aggregate concrete; High temperature; Materials of engineering and construction. Mechanics of materials; 0201 civil engineering

The use of basalt fiber-reinforced recycled aggregate concrete (BFRRC) can effectively treat waste concrete and reduce the consumption of natural resources. BFRRC is often in complex triaxial compression in engineering applications and may exposure to high temperature conditions. To evaluate the conventional triaxial compression mechanical performance of BFRRC after exposure to high temperature, 324 cylindrical specimens were produced. The specimens were designed and fabricated by varying several experimental parameters: the recycled coarse aggregate replacement ratio, basalt fiber dosage, temperature, and lateral confining pressure. The specimens previously exposed to high temperature were subjected to conventional triaxial compression tests and the effects of various experimental parameters on the mechanical performance indexes of BFRRC were analyzed. The results show that the peak stress and elastic modulus of BFRRC all raise with greater fiber dosage and confining pressure but decrease with higher replacement ratio and temperature. The maximum increase of the peak stress and elastic modulus is 352.45% and 224.59%, respectively. The peak strain of BFRRC has two variation trends of gradual increase and gradual decrease with the replacement ratio rising. And the peak strain gradually grows with the temperature and confining pressure increasing. The fiber dosage, however, does not exert the considerable impact on the peak strain. The maximum increase of the peak strain is 132.22%. The research provides a scientific basis for the triaxial mechanical performance, fire resistance design, and post-disaster assessment of BFRRC, and promotes the popularization and application of BFRRC in building structures.