Innovations in the technology for producing asphalt concrete based on neutralized catalyst as a condition for improving the quality of road surfaces

Abstract

Abstract The conditions of safety and environmental friendliness of the operation of roads as an international key problem of our time are disclosed. Objective reasons are shown that reduce the quality indicators of the construction and operation of roads. A call to the technology for producing asphalt concrete based on spent alumina-chromium catalysts is a timely need, due to the increasing requirements of international and Russian standards for the quality of roads and their operating conditions. The main scientific idea is to obtain asphalt concrete based on reduced aluminum-chromium catalyst to improve the quality of road surfaces. A safe method is proposed for converting toxic waste into safe raw materials, taking into account the conversion of chromium (VI) compounds to chromium (III), which makes it possible to use it as part of asphalt concrete coatings. The optimal amount of alumina-chromium catalyst in the composition of asphalt concrete (6.4 ÷ 12.5 wt. %) is shown. It is proved that the use of reduced aluminum-chromium catalyst in the composition of asphalt concrete increases the proportion of waste in the total raw material balance, expands the range of building materials used in atmospheric conditions. Samples of asphalt concrete mixtures were prepared and tested according to ISST 9128-97 with the use of spent catalyst additives. The analysis of the current state of road surface coating technology is carried out. The optimal formulation for the preparation of asphalt mixes based on the spent catalyst having indicators of physical and mechanical properties is better than a standard sample of asphalt concrete. An effective method is proposed for removing toxic hexavalent chromium from spent catalyst as waste by transferring it to non-toxic trivalent chromium. One of the long-term problems of improving the quality of road surfaces with the inclusion of reconditioned spent aluminum-chromium catalysts, as a solution to the industrial and environmental safety of an industrial enterprise and improving the quality of operation and durability of road surfaces has been solved.