INVESTIGATION OF THE WETTING EFFECT OF SURFACTANTS OF VARIOUS NATURE IN THE BITUMEN COMPOSITION

Abstract

Asphalt concrete coverings are short-lived and are destroyed under the influence of external factors. The insufficient degree of adhesion at the interface between the bituminous binder and the hard surface of the mineral material causes a low hydrophobicity of asphalt concrete coatings, which is the main cause of damage and premature wear of the roadway. Optimization of the bitumen composition by introducing a variety of modifying agents can intensify the processes of wetting the hard surface with bitumen and increase the hydrophobicity of the surface films formed by it. The purpose is to establish the influence of various modifiers on the processes of wetting the surface of crushed stone with a bituminous composition, as well as to study the regularities of the influence of modifiers on the hydrophobicity of bituminous films. The methodology of this work included experimental determination of the wetting contact angle θ of a solid surface by the lying drop method at T=298 K. Results. Increasing the AC-2K content in bitumen from 0 to 1% reduced the contact wetting angle by 11.31° (relative to the base version without the modifier) to 114.35°. The AC-2 modifier contributes less to improving the wettability of the surface of the basic crushed stone with bitumen; with Cm=1%, the contact wetting angle is reduced to 118.68°. When modifying bitumen, PPS recorded a significantly smaller decrease in wetting contact angle at a higher concentration (Cm=2%) – by 2.4° (from 125.66° to 123.26°). The amino derivative AC-2K (Cm=1%) has the greatest water-repellent effect among the studied modifiers, increasing the wetting edge angle to 99.07°. Conclusion. The water-repellent properties of bituminous compositions are enhanced (Δθ=4.02°) at a narrow range of concentrations of the modifier AC-2K (with Сm=1%). The ultrasonic cavitation-derived AC-2K can be recommended for use in asphalt concrete coatings as an adhesive additive that provides a good wetting effect of bitumen in relation to the surface of the mineral filler while also increasing the hydrophobicity of bitumen films.