Performance attenuation and mechanism of basalt-fibre-reinforced concrete under fatigue load and freeze–thaw cycles

Abstract

ABSTRACTTo explore the performance attenuation and mechanism of basalt-fibre-reinforced concrete (BFRC) in cold areas, the changes in the properties of BFRC were discussed under two conditions: the freeze–thaw environment and the coupling of fatigue load and freeze–thaw cycles, and the process of pore deterioration and microcrack propagation was studied quantitatively via mercury intrusion porosimetry and electron image analysis. The results showed that the frost resistance of concrete first improved and then worsened as the basalt fibre length and content increased; the optimum length and content of basalt fibre are 12 mm and 1.96 kg/m3, respectively, based on frost resistance. The performance attenuation of BFRC was lower than that of ordinary concrete under coupling conditions, and the enhancing effect of basalt fibre was more obvious with an increase in the stress level. Basalt fibre alleviated the pore deterioration, and the increase in the amplitude of more harmful pores in BFRC was reduced by 4–5%. The area density and width of cracks were reduced under coupling owing to the anti-cracking effect of the basalt fibre, accompanied by the complication of crack morphology.