Basalt plastics — new materials for road construction

Abstract

The effectiveness of using basalt fibres and substandard basalt wool — large-tonnage waste from chemical plants and nuclear generating stations — as a reinforcing component in road construction was demonstrated. Incorporation of basalt fibre or wool in asphalt concrete in an amount of up to 0.4 wt. % increased the strength characteristics of the asphalt concrete by 10-30%. The presence of a physicochemical reaction in the basalt fibre—polymer-asphalt binder system, which increased the strength characteristics, heat resistance, and lifetime of the polymer—asphalt—concrete, was demonstrated. IR spectroscopy showed ordering of the structure of the PAB due to formation of organosilicate compounds that strengthened the structure of the polymer asphalt concrete. The status of a developed country implies a branched infrastructure with modern highways. However, high-quality road construction is impossible without the use of new materials and technologies. The petroleum asphalt used in road construction, fabricated based on the residual principle, has low characteristics. The use of domestic modifiers to increase them is frequently ineffective and use of foreign modifiers is impeded by their high cost. Reinforcement with fibres is a promising direction for raising the properties of composite materials. However, chemical fibre production volumes are currently so small that they cannot satisfy even textile industry demand. Only the dynamically developing production of basalt fibres exhibits a positive trend. The intensive development of basalt fibre production in the territory of Russia is due to the high demand for these fibres, which greatly outstrips the supply. Basalt fibres have unique properties: a high level of physicomechanical and chemical properties, high resistance to aggressive media and vibrations, sound-insulating capacity, long lifetime, stability of properties in prolonged use in different conditions, high adhesion to binders, and heat and fire resistance. All of these positive properties make basalt fibres extremely promising for production of new composite materials — basalt plastics and articles with different functional applications. Use of basalt fibres and basalt wool as the reinforcing component in asphalt concrete to increase its performance properties is very important. The efficacy of reinforcement is determined by the adhesive reaction between the polymer matrix and the reinforcing component to a significant degree, evaluated here by capillary rise (Fig. 1) of the polymer-asphalt binder (PAB). It was found that the best wettability is characteristic of basalt fibre and standard basalt wool. We noted that the oiling agent did not significantly affect the wettability. The study of the reaction in the basalt fibre—PAB system (Fig. 2) showed splitting of the intense fundamental absorption band of Si—O bond stretching vibrations (1091 cm -1 ) in PAB into two components (1062 and 1031 cm -1 ). This suggests that the SiO group participates in formation of chemical bonds with the functional groups in the components of the PAB, primarily the OH group of aromatic compounds and carboxylic acids in the asphalt: