Experimental Investigation on the Frost Resistance and Service Life Prediction of Basalt Fiber-Reinforced Concrete

To evaluate the frost resistance of basalt fiber-reinforced concrete (BFRC) and predict its service life, this study conducted 225 quick freeze–thaw (F-T) cycle tests. Specifically, it systematically investigated how basalt fiber (BF) volume content (0.1%, 0.2%, 0.3%) and the incorporation method (single-doped 18 mm, mixed-doped 6 mm/12 mm/18 mm) affect concrete frost resistance. Meanwhile, a two-parameter Weibull distribution model was established to quantitatively predict the service life of BFRC. The results showed that BF significantly improved the frost resistance of concrete: the reference group without BF had a relative dynamic elastic modulus (RDEM) of less than 60% after 25 F-T cycles, while the group with 0.3% volume content of single-doped 18 mm BF still maintained structural integrity after 225 F-T cycles, with a frost resistance grade exceeding F225. Furthermore, within the scope of this study, the frost resistance effect of single-doped 18 mm BF was better than that of mixed-doped BF, and the frost resistance of concrete gradually improved with the increase in BF volume content. In high-altitude cold regions (e.g., Songpan County, Sichuan Province) with 85 annual F-T cycles, the predicted service life of BFRC with 0.3% single-doped BF reached 49 years, which was approximately 25 times that of the reference group (2 years). This study delivers a systematic comparison of the frost resistance between single-doped long and mixed-doped BF, along with a targeted life prediction model for high-altitude cold regions (85 annual F-T cycles, annual temperatures below 6 °C), which collectively offer a theoretical and technical basis for BFRC durability design in freeze–thaw environments.