Study of the Hydrophysical Properties of Heavy Concrete Modified With an Organomineral Additive and Micro-Reinforcing Fibers

Abstract

The main task of the implementation of 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, in particular, for heavy concrete, are considered. The mechanism of the structure formation process, the method of introduction and the optimal consumption of the additive for modifying the concrete mixture have been determined. With the help of a comprehensive study, the products of dispersion of microsilica, which is part of the complex modifier, have been determined. It has been established that the process of the chemical activation of mineral particles has not been sufficiently studied, in this regard, the presented studies, which consist in finding solutions to increase the operational characteristics due to the process of pretreatment of microsilica with an alkaline medium pH = 10.2 together with a micro-reinforcing component, are relevant. The aim of the study is to establish the positive effect of the activation process of silica fume together with 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. Further modification with a complex additive (high-water-reducing additive "MasterGlenium 115" with a consumption of 1% plus a reaction-chemical additive with microsilica grade MKU-95 - 15% of the binder mass) together with basalt fiber, improves the following characteristics: water absorption - 2%; waterproof grade - W14; frost resistance - F600, which makes it possible to apply this composition in practice to obtain building products and structures with specified characteristics in harsh operating conditions.