Usage of new materials during rehabilitation of road structure using cold recycling technology

Abstract

Until recently, the most common way for recovering of damaged and worn asphalt pavements on Ukrainian roads remains the provision of additional reinforced layers over the old pavement with patching. However, such measures give only a short-term effect because after one or two years, the existing deformations and fractures beneath reinforced layers occur, especially in conditions of insufficient strength of the foundations. But nowadays, recycling technology of different variations became the main method of existing pavement renovation. The economic attractiveness of cold recycling technology is primarily in the reuse of existing road material for arrangement of new pavement layers, so there is no need to arrange special areas for storage and disposal of old asphalt. In addition, the use of such technology helps to minimize the harmful impacts on the environment during road repair works. The essence of cold recycling technology, which is the most widely used in Ukraine for the arrangement of a road foundation layer, is in the fact that the defective and destroyed pavement layers are strengthened directly by complex admixtures of organic (hot bitumen, bituminous emulsion, foamed bitumen) and mineral suspensions, lime) binders. Cold recycling, according to the complications of the work, is divided into several types, depending of the depth of cutting. The choice of a particular type of recovery depends mainly on the condition of the entire pavement structure, which is determined prior to the start of repair works. Optimal mis design of the organic and mineral mixture for the arrangement of the road foundation layer by cold recycling technology is also executed before the beginning of the works. Actually, the main direction of cold recycling technology research in Ukraine is the usage of new materials such as fiber - basalt or polymer, stabilizing additives (ionic or polymeric), industrial waste - slags of various types of production or other by-products. Performed studies have shown that the use of organic and mineral mixtures of optimal design with the insertion of basalt fiber increases crack resistance and durability of the arranged road foundation layer.