Composite Materials Based on Plasma Treated Basalt Fibers for Heavy-Duty Concrete Products

The paper investigates the effect of plasma treatment of basalt fiber on its wettability, which is determined by the ability to absorb water. As the treatment time increases the wettability becomes higher, up to 10 minutes. The wettability-treatment power dependence passes through a maximum. The highest value is observed at a treatment power of 0.6 kW both on the day of treatment and after a 5-day rest period. A further growth in power not only does not increase this value, but in fact decreases it. The retreatment after a 5-day curing period yields lower results, but remains sufficiently high. The highest wettability is observed at a treatment power of 0.6 kW, gas flow rate of 0.04 g/s, chamber pressure of 20 Pa, air/argon mixture (1:1) as plasma support gas. The strength of concrete specimens BST V40 P2 was tested with two treatment modes: in mode 1 the treatment time was 10 minutes, the treatment power was 1.5 kW; and in mode 2 the treatment time was 5 minutes, the treatment power was 0.6 kW, with the addition of plasma treated basalt fiber (0.5 and 3 mass percent). Concrete has the highest strength when basalt fiber (3 mass percent) is subjected to plasma treatment in mode 2. In addition, the strength increases by 18 mass percent in comparison with the reference.