SCIENTIFIC AND TECHNICAL BASES OF PRODUCTION OF SOIL-BLOCKS

Currently, the problem of efficient use of different types of soils whose properties are improved by cementitious materials and other chemicals for the arrangements of road and airfield carpets, is practically solved. However, when using local soil for the soil blocks production, there are many outstanding questions concerning the technology of their production, there is no theoretical justification of high quality soil blocks production as the wall material. It must be assumed that the strength and other properties of soil blocks depend on such factors as the soil grading and mineral composition, quantity, composition and activity of added binder, molding humidity of mixture, degree of the soil preliminary grinding and the quality of components mixing, method and compacting mode, the mode and period of hardening products. Various additives may have also significant influence. Depending on the combination of these factors, the properties of soil blocks may vary within wide limits. This work is devoted to a partial solution of these problematic issues. Particularly large amount of work using soil cement as a base or road surface is done in the United States. The annual volume of work using this material reaches 80 million m2. Soil cement is used in England, France, Poland, Germany, Romania, Hungary, Czech Republic. Here the main idea of using different methods to strengthen the soil is the use of local soils as a source of cheap raw materials, as a result of providing the appropriate processing to obtain high-grade substitutes of stone materials [3]. Particular emphasis needs to be placed on the work of Popov N. A., Skramtaev B. G., Higerovich N. I. regarding manufacturing techniques and the use of wall materials from soil-cement mixture [10; 11; 14]. These works contain recommendations on the choice of soil for soul blocks, production technology of these products. In the paper [6: 8], there are given existing experience of the construction of buildings of soil blocks made of cement-soil mixture, equipment for the production of such products, some of their properties are investigated. However, in our opinion, the composition of cement-soil mixture, forming modes, providing production of high strength products with allowable density of wall materials is insufficiently substantiated in these papers. Objective. Develop scientific and technical bases for the production of high-quality products using local cement and soil. Run the appropriate experimental studies to optimize the cement-soil mixture (soil-concrete), water consumption, soil blocks forming mode. Conclusions. Scientific and technical bases for the production of high quality blocks of soil using cement and local soils are developed. It was established that for any method of manufacture of such products there should be the principle of active influence on the change of colloid-chemical properties of the used soil that determines the nature and kinetics of the interaction of soil with cementitious materials and, consequently, the quality of the soil blocks. It was defined a rational part of the cement-soil mixture, water consumption, amount of pressure, which provide sufficient strength of soil-concrete at the required density as a wall material.