FEATURES OF SELECTING THE COMPOSITION OF FINE-DISPERSE BINDERS FOR INJECTION

The use of injection mixtures based on finely dispersed mineral binders (microcements) intended for injection formation of hardened massifs (soil concrete) in permeable soils (sands of all kinds) makes them economically feasible in solving a wide range of different geotechnical problems. For the correct assignment of the parameters for the use of finely dispersed binders for the injection of soils, appropriate criteria for assessing their properties have been developed. However, the question of assigning the consumption of raw materials to obtain soil concrete structures and hardened massifs with the required properties remains poorly studied. Nowadays, the regulatory framework for finely dispersed binders (micro binders) used in injection is practically not presented in the Russian Federation. There is no scientific basis for the formation of soil concrete formed by injection, including there are no adequate dependencies like the Bolomey-Skramtaev formula for concrete, which reflects the resulting strength from the consumption and quality of the components. The series of experiments were conducted, showing the inapplicability of the basic laws for standard concrete when creating soil concrete obtained by injection methods. Various types of finely dispersed binders used in geotechnical construction are considered. As control parameters, the particle size and mineral composition of finely dispersed binders were compared. There were assessed penetration at different modes of preparation and injection of the injection mixture into the soil, and the characteristics of the resulting concrete. Two technologies for creating soil concrete - by mechanical mixing and by the method of injection impregnation of control samples of sandy soil were compared for compliance with the principles of selecting the composition of existing regulatory documents for heavy and light concrete. Significant differences between the properties of soil concrete obtained by the methods of injection impregnation and mixing are confirmed. Studies have confirmed the possibility of injection impregnation with binders of a certain composition in order to strengthen sandy soils in accordance with the assigned technological parameters. The coefficients of the efficiency of the use of micro binders during injection are shown, data on the properties of the formed soil concrete at different technological parameters are reflected.

fine-disperse binder, injection, soil hardening, soil-concrete, microcement, micro-filler, impregnation injection