"Вестник МГСУ"

Creating an effective insulation envelope of the building is possible only using high-quality materials, preserving their characteristics both in the early stages of operation, and for the whole billing period. It is an important opportunity to assess the thermal insulation properties and predict its changes over time directly in the conditions of the construction site. The products based on mineral fibers (rock and glass wool, basalt fiber) are the most widely used type of insulating materials in the domestic construction. Therefore, the operational stability valuation methods must be primarily created for this group of products. The methodology for assessing the thermal insulation properties includes two main components: testing equipment and methodology for assessing the operational stability. The authors tested the methodology of the accelerated testing and prediction of durability for mineral wool products of laminated, corrugated and volume-oriented structures. The test results give good convergence with the methods recommended by the building regulations. Application of thermal insulation materials are an effective way to form the thermal envelope of the building, reducing energy costs and increasing the durability of building structures. The material properties are determined by their structure, which is formed during the technological impacts.

Lime-belite binder is obtained by low-temperature firing of natural marl, marling or sanding limestone and artificial lime-silica mixtures. The binder with calcium oxide also contains significant amounts of dicalcium silicate and some others materials, the composition and quantity of which depend on the chemical composition and firing temperature of the raw materials used. The authors investigated the kinetics of hydration structures and physicochemical properties of lime-based binders on the basis of belitic marl from Akburly and Porlytau. The formation of resistance is associated not only with the formation of the system of different types of structures - coagulation and crystallization, with the transition of the first to the second, but also with the different stages of formation of crystal structures. The possibility of using lime-belitic binders for the preparation of high-strength products of autoclave hardening is proved. The autoclaved binders used in the manufacture of sand-lime products are prepared with the use of mixtures consisting of 60...70 % lime-belite binder and 30...40 % ground quartz sand.

Lime-belite binder is obtained by firing natural marls, marlized or sanded limestones, as well as artificial silica-containing mixtures at temperatures of about 1000 °C with exposure of 90 minutes. Along with calcium oxide, the binder contains significant amounts of dicalcium silicate and some other minerals the composition and quantity of which depend on the chemical composition and firing temperature of the raw materials. However, silicon oxide is not enough to form in the firing products of raw marl the required amount of belite needed to obtain high strength properties. The main research purposes were selection of the initial compositions and study of the chemical and mineralogical binder compositions on the basis of marls of the Akburly and Porlytau deposits in order to increase the content of belite (?-С2S) in the heat treatment products and obtain a high-strength binder. 5, 10 and 20 % of ground quartz sand were injected into the raw material to increase the content of belite (?-С2S) in heat treatment products and obtain the high-strength binder. The quartz sand was ground up until it completely passed through a 008 sieve. The specific surface area was within the range 2500 ... 3200 cm2/g. It was shown that the basicity constant decreases as the sand content increases, and the content of aluminates, ferrites and calcium sulphates is almost unchanged, since the sand contains no clay components. The study results of joint heat treatment of marls and ground quartz sand suggest that the optimum sand content in the raw mix should be 10 %. With such proportions of heat-treated raw material components, their interactions result in the formation of a relatively large amount of belite which will provide the high strength properties of products based on this binder.

For the purpose of soil strengthening or increasing water impermeability, the cement grouting is widely used in the underground construction in conditions of dense urban development. An obvious advantage of cement grouting is environmental safety, high performance, durability, economic attractiveness. The ground conditions of the urban environment are characterized by extreme heterogeneity, which necessitates the use of various technological solutions for their cement grouting. In this work the analysis of application of various technologies of inject grouting providing the given efficiency of the accepted design decisions is executed.