MECHANICAL ACTIVATION OF QUARTZ SAND POWDERS

The possibility of assessing changes in activity is shown powder materials as components of composite binders, obtained by mechanoactivation of quartz sand. The functional relation-ship between the relative change in the surface energy of the samples and the time of mecha-noactivation is established.Работа выполнена на основе гранта РФФИ 18-43-292002

HYDROPHOBIZATION OF THE WOOD SAMPLES SURFACE WITH SILICA-CONTAINING COMPOSITION

Mineralization of the wood surface with compositions containing silica particles gives an increase in density and hardness, as well as the acquisition of hydrophobic properties. This indicates the possibility of using the compositions for use in wood petrification.Исследования выполнены под научным руководством к.т.н., доцента Данилова В.Е и д.х.н., профессора Айзенштадта А.М. Работа выполнена на основе гранта РФФИ 18-43-292002

Potentiometric method for assessing the pozzolatic activity of highly dispersed materials

ABSTRACT: Introduction. Pozzolatic activity is an important indicator for highly dispersed materials, particularly clay soils. It determines their effective use and characterizes the ability of the active components in their composition to interact with calcium hydroxide. Various methods are employed to assess this pozzolatic activity. Potentiometric methods are effective. They are based on measuring the electrode potential, which is functionally related to the change in the concentration (activity) of calcium ions in the analyzed solutions as the main information parameter of the pozzolatic reaction. The purpose of the research is to test the potentiometric method to assess the pozzolatic activity of highly dispersed materials, as well as the application of suggested approach to determine the rational amount of an active mineral lime-containing additive as a binder component for producing soil-concrete. Materials and Methods. We have chosen clay soil models with different plasticity index and sandy loam of the Arkhangelsk region as the objects. The potentiometric analysis method involved sequentially adding 0.015 mol/l calcium hydroxide solution, in amounts ranging from 0.2 to 0.8 ml, to a suspension containing 0.5 g of soil in 80 ml of distilled water. The potential of the system was measured while continuously stirring at a fixed speed. Results and Discussion. All studied objects are characterized by the pozzolatic activity, which increases in the series sandy loam sandy → clay loam light silty → clay light silty ≈ sandy loam silty and has the order of absolute values coinciding with the literature data. The rational amount of the active mineral lime-containing additive was 1–2% for clay soil models, depending on the plasticity index, and more than 2 % for the sandy loam of the Arkhangelsk region (from the soil mass on dried basis). Conclusion. We have shown the applicability of the potentiometric method of analysis using a calcium-selective electrode to assess the pozzolatic activity of highly dispersed materials on the example of models of clay soils with different plasticity index and sandy loam of the Arkhangelsk regio

A comprehensive summary of available legislation and practices in demolition and construction & demolition waste management in the arctic region

Abstract The need for better natural resource use is currently increasingly recognised, and high emphasis is given to the circularity of building materials and the reduction of activities with negative environmental impact. Legislation, guidelines, and other documentation play an important role in improving demolition activities and construction and demolition waste (CDW) management. Good practices in CDW handling is not achievable without knowledge about CDW recovery techniques described in guidelines and other documents. Demolition activities in arctic regions could be more challenging due to harsh climate conditions, and therefore the cooperation between Russia, Norway and Finland was established to boost the uptake of good practices in demolition activities and CDW management. The main subject of this article is an overview of presently used demolition practices, CDW management, and verification of areas where practices with lower environmental impact and increase of material circularity could be utilised. Two fundamental documents, namely “EU Construction & Demolition Waste Management Protocol” and “Guidelines for the waste audits before demolition and renovation works of buildings” [1, 2], were published by the European Union (EU) in 2019 and serve as a foundation for changes in demolition activities and CDW management in EU and adventitiously also in the Russian Federation and Norway