STUDY OF THE HYDROPHYSICAL PROPERTIES OF HEAVY CONCRETE MODIFIED WITH COMPLEX ORGANO-MINERAL ADDITIVES

Abstract

The main task of implementing environmental policy is to create a resource-efficient system for the placement and disposal of industrial waste and secondary raw materials, in particular, in the production of building materials and products of specified properties. Within the framework of these studies, issues related to the activation of microsilica, which is a waste of ferroalloy production, and methods of its use for modifying the structure of cement stone, particularly for heavy concrete, are considered. The study aims to establish the positive effect of the activation process of silica fume and a micro-reinforcing component on the modification of the structure of heavy concrete to increase the hydrophysical properties. The object of research is a modified heavy concrete based on activated microsilica with a micro-reinforcing component. In this work, the following research methods were used: physicochemical activation of microsilica with water, treated by electrolysis with the Melesta device; determination of the frost resistance grade in the WK3 180/40 climatic chamber; water tightness was determined in the UVB-MG4.01 installation; water absorption was determined using a SNOL electric digital oven. Research results: a positive effect on the hydrophysical properties of heavy concrete was established by reducing the content of the binder (cement) and replacing it with a microdispersed filler previously activated with an alkaline medium with pH = 10.2. It has been experimentally proven that the modified concrete composition exhibits improved hydrophysical properties compared to the control: water absorption – 2%; water impermeability grade – W14; frost resistance – F600 with a mass loss of up to 1.9% and a strength loss of 8%, which is due to the formation of a microporous structure in the cement stone with pore sizes up to 0.1 μm.