As a result of artificial carbonization of slag, construction materials can be obtained. For this purpose, a technology has been developed for producing durable construction products as a result of accelerated carbonization of slag minerals with carbon dioxide (CO2) at elevated pressure (up to 2 MPa) and temperatures (20-60°C). The carbonates formed during the carbonization reaction act as a binder, sticking the slag particles together. Carbonized compacts after autoclave processing have technical properties equivalent to conventional concrete products made on the basis of Portland cement. The technology was developed in laboratory and production conditions by optimizing the parameters of the technological process (pressing force, temperature in the autoclave chamber, carbon dioxide pressure in the autoclave chamber and carbonization time) taking into account the increase in compressive strength and frost resistance of the samples.

Keywords: small-sized products, binder, preliminary preparation, steel slag, pressing, accelerated carbonization, minerals, carbon dioxide, strength, frost resistance

The purpose of the study is to determine an effective modifier of the structure of a slag-alkaline stone, characterized by a low value of linear shrinkage and a decrease in cracking in the early stages of hardening. Ground blast furnace slags were activated with aqueous solutions based on sodium silicate and caustic soda. Fly ash and zeolite-containing clay were used as modifiers of the cement stone structure at a dosage of 5, 10 and 15% of the binder consumption. The results of the study showed that an increase in fly ash content does not significantly affect the setting time. The use of zeolite-containing clay as a slag-alkali binder modifier makes it possible to regulate the setting time of the binder at a dosage of more than 10%. Cracking of the slag-alkaline matrix was observed only for mixtures without fly ash and zeolite-containing clay.

Keywords: cement stone, slag-alkali binder, hardening activator, structure modifier, fly ash, zeolites, shrinkage, cracking

The production of Portland cement can be characterized as harmful to nature and human society, resource and energy consuming. The use of by-products of metallurgical and chemical production in obtaining a hydraulic binder is a relevant and promising direction. binder for strengthening and stabilizing the soil of the road base The article investigates the regularities of the initial hardening processes of finely ground slag occurring during structure formation as a result of activation with alkaline solutions and sodium silicates.

Keywords: granular slag, normal density, setting time, activation, awakening of hydraulic activity, binder, hardening

The physicomechanical properties of paving slabs produced by vibropressing technology are determined. The compositions of fine-grained concrete using quartz fine-grained sands and very fine sands are proposed. The obtained results confirmed the possibility and effectiveness of the use of substandard fine-grained raw materials of the local raw material base, which ensure a reduction in the cost of production.

Keywords: fine-grained concrete, vibrocompression, raw material base, substandard sands, ground sand, active rheological matrix