Evaluation of the effectiveness of elastomeric modifiers of road bitumen and asphalt concrete mixtures based on gel-sol analysis

Description

Evaluation of the effectiveness of elastomeric modifiers of road bitumen and asphalt concrete mixtures based on gel-sol analysis

SHAKHOVETS S.E., Doctor of Technical Sciences, Director of Research and Development LLC “NEWFALS”, Saint Petersburg;

MAIDANOVA N.V., PhD (Engineering), Head of the Research Center of JSC “ABZ-1”, Saint Petersburg;

MELNIK O.Yu., Director of Technology and Quality, “DSK ABZ LLC-Dorstroy”, St. Petersburg;

Abstract. The paper demonstrates the necessity of an objective method of quality control for road construction modifiers based on rubber powder obtained from cushioned tires. The physical parameters of modifiers specified in the current regulatory and technical documentation do not guarantee the production of high-quality rubber-bitumen binders (RBB) or asphalt concrete mixtures. To evaluate the physico-mechanical properties of modifiers, the gel-sol analysis method is proposed. Based on the results of the research, a gel-sol modifier control method is proposed, which allows for input control throughout a work shift. The gel content in known elastomeric modifiers for RBB is studied in comparison with the gel content in untreated rubber powder. The range of gel values that characterize the effectiveness of elastomeric modifiers is determined by using examples of structure formation in bitumen when measuring the dynamic viscosity and stability of RBB during their formation. It is concluded that it is advisable to include gel size determination by gel-sol analysis in the RTD for elastomeric modifiers.

Keywords. Elastomeric modifier, rubber-bitumen binders, gel-sol analysis methods, Soxlet extractor, solvents, bitumen structure formation, dynamic viscosity.