THE INFLUENCE OF FINE AGGREGATES ON THE CHARACTERISTICS OF VIBRO-COMPRESSED CONCRETE BASED ON ULTRA-HARD MIXTURES

Abstract

The publication highlights the problems of physical-mechanical and physical-chemical properties of inert aggregates and cohesive vibro-pressed shaped paving elements, which are manufactured on modern blockmaking machines of leading German machine-building manufacturers based on fine-grained ultra-hard and hard concrete mixtures in the latest conditions of development of the construction industry in Ukraine. An analysis of factors affecting the operation of concrete paving stones and causing increased requirements for their physical-mechanical properties has been conducted. In this article, the author studies the granulometric composition, sieving curves, chemical composition, X-ray phase analysis of the product of grinding strong rocks, washed construction sand with gradation factor more than 2.1 and the chemical composition of Portland cement CEM 42.5 produced by "Ivano-Frankivskcement", which are used in the production conditions of the Trade Mark "Mii Dvir" for the production of fine-grained concrete mixtures using specialized dosing and mixing equipment in the process of serial production of figured paving elements. The article determines the main factors that form the strength characteristics and durability of concrete at the early and late stages of its hardening; considers the factors that create conditions for factory vibropressing of products of this category and provides components that should be considered optimal for creating highly efficient ultra-hard concrete mixtures. The materials of the publication present experimental data on the content of the main components of concrete in each of the layers of building products. These studies were conducted in the scientific laboratory of the National University "Lviv Polytechnic" according to domestic and European standards by the method of forming beams measuring 40x40x160.