Improvement of mechanical characteristics of mortar by using of wollastonite
Geomimetic (nature-like) principles are proposed for optimizing the strength properties of cement mortar, consisting in the integrated effect of wollastonite on the processes of structure formation of cement paste. At the same time, wollastonite (2, 4, 6 and 8 % of the weight of cement) in the composition of mortar has a double function: it serves as a filler (silica-containing component) and microfiber. It was revealed that the incorporation of wollastonite into the mortar mix makes the material easier without sacrificing strength. It has been proven that in the initial period of hardening (3 and 7 days), hydration processes are accelerated, and early strength for all formulations developed with the addition of wollastonite is higher than for the control specimen. An analysis of the structure formation of cement paste from the standpoint of geomimetics reveals the similarity of wollastonite CaSiO3 to the main minerals of the Portland cement clinker Ca2SiO4 (belite) and Ca3SiO5 (alite). This similarity leads to the creation of a chemically uniform and, accordingly, strong microstructure. Micro reinforcement of the mortar matrix with wollastonite occurs due to the elongated shape of the microfiber and its good adhesion to the mortar matrix. The results can be used by technologists in the design of mortar mixes for the construction of buildings and structures for various purposes.