Optimization of composite coatings structure to protect working equipment of recycler mixing chamber

Abstract

Introduction. Cold-in-Place Recycling (CIR) technology is an effective solution for pavement maintenance and rehabilitation. However, the mixing chamber of CIR equipment is simultaneously exposed to severe mechanical abrasion, impact loading from reclaimed asphalt pavement (RAP), and aggressive chemical environments associated with bitumen–water emulsions. These combined effects result in complex degradation mechanisms that significantly reduce the equipment’s service life.

Materials and methods. This study focuses on the evaluation and development of optimized polymer–composite coating systems for CIR mixing chambers. The approach is based on selecting matrix resins, including epoxy and polyurethane/polyurea systems, and combining them with multifunctional fillers, such as solid lubricants, reinforcing agents, and nano- and micro-phase components.

Results. A multicriteria optimization methodology was applied to achieve a balanced combination of mechanical, physico-chemical, and operational properties, including adhesion strength, hardness, elasticity balance, wear resistance, friction reduction, impact toughness, chemical and thermal stability, and practical applicability and manufacturability.

Discussion and conclusions. The results indicate that epoxy matrices reinforced with hybrid nano-micro fillers and supplemented with solid lubricants substantially enhance coating service life, improve tribological performance, and reduce both coating delamination and RAP bitumen adhesion, while maintaining reasonable cost and process ability. Furthermore, the proposed design strategy provides a novel practical approach for developing protective coatings in other industrial sectors where resistance to abrasion, impacts, and chemically aggressive conditions is required.