EFFECT OF WOLLASTONITE ON THE MECHANICAL CHARACTERISTICS OF CONCRETE

Improvement of the physical and mechanical properties of cement composites should be accompanied by the disposal of industrial waste of various generation. Therefore, the paper proposes the principles of controlling the strength properties of concrete, which consist in the complex effect of wollastonite obtained from boron production waste on the processes of structure formation of the cement matrix. When this introduced in an amount of 2-8 wt. % wollastonite has a dual function as a mineral filler and a reinforcing fiber. It has been proven that in the presence of wollastonite, the concrete mix becomes lighter without reducing its physical and mechanical properties. It was revealed that the early strength for all the developed compositions with the addition of wollastonite increases due to the acceleration of hydration processes. Calcium silicate, which is wollastonite CaSiO3, has a close chemical composition with cement clinker, especially with Ca2SiO4 belite and Ca3SiO5 alite. This leads to the formation of a chemically homogeneous and, as a result, hardened microstructure. Elongated wollastonite fibers with good adhesion to the cement stone provide effective micro-reinforcement of the concrete composite. Using the results will lead to the possibility of designing high-strength concretes, including for special structures