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Recycling - the process of transforming waste into new materials - represent a modern alternative for eliminating waste and reducing emissions of greenhouse gases. Recycling - part of the 3Rs (Reduce, Reuse, Recycle) in the hierarchy of waste - helps to reduce the consumption of raw materials and to reduce energy consumption, air pollution (in phase of combustion waste) and water (in phase of waste storage). Among the recyclable materials such as glass, paper, plastic, metal, textiles are used tires. These tires are a source of waste because of the high volume of products - requires large storage space, enhanced tire durability and the fact that the ecological tire components is a big problem - they are non-biodegradable materials. Often the tires are burnt to the detriment of environment but there are concerns constantly using them as recyclable material. Thus, between the uses of recycled tire it is crumb rubber modifier that used in asphalt mixture leads to a Rubber Modified Asphalt Mixture type. In this context fits this paper that shows a possibility of using rubber asphalt mixture used in the wearing course of pavement. It is studied in the laboratory the mix of aggregate, filler and bitumen (AC12.5 asphalt mixture type) together with an addition of Road+ additive (containing crumb rubber) and Gilsonite additive (pure bitumen) compared to the mixture without additives. The aim is obtaining better physical and mechanical characteristics that lead to good behavior asphalt layer in service. [ABSTRACT FROM AUTHOR]

Superior capitalization of industrial waste as: slag heaps, plastics and rubber, vegetable and animal oils, natural or synthetic fibers, make significant contributions to reducing pollution, environmental protection, to increase eco-efficiency, reduce production costs per km of paved road. From the point of view of physical and mechanical properties most suitable materials that can replace mineral aggregates are blast furnace slag which after waste processing and sorting through the appropriate dimensions can successfully replace aggregates and gravel quarry. Partial or full replacement of mineral aggregates with blast furnace slag, obtained by superior processing, no pollution and ecological technologies, are easily accessible and competitive with classical materials. "Warm mix" technology is a relatively new technology that appeared and developed first from the necessity to environmental protects and thanks to economic benefits, too. Warm mix asphalt (WMA) refers to asphalt mixtures that are produced at temperatures approximately equal to 100°C - 140°C bellow temperatures typically used in the production of hot mix asphalt (HMA). The goal of WMA is to produce mixtures with similar strength, durability, and performance characteristics as HMA using substantially reduced production temperatures. The main scope of this paper is to present an asphalt mixture recipe with blast furnace slags for base course that can be applied successfully for low traffic pavement instead off conventional asphalt mixtures with crushed or rounded aggregate according to our country norms. The laboratory studies were performed in Roads Laboratory of Technical University of Civil Engineering Bucharest. The paper presents comparatively the behavior of the AC31.5 base 50/70 asphalt mixture with blast furnace slag produced using "hot mix" technology and "warm mix" technology. Tests according European norms such as Marshall Stability and Flow water sensitivity, stiffness, permanent deformation and fatigue life were performed and the performance of this warm mix asphalt was shown by graphs, tables and conclusions. [ABSTRACT FROM AUTHOR]

According to internationally studies, it has been demonstrated that natural aggregates can successfully replace with blast furnace slag which by size-sorting and processing are appropriate in terms of physical and mechanical properties. Using slag in asphalt mixture has some important advantages for environment protection in this way decreasing slag deposit existing in our country and saving local resources. Ecological asphalt mixtures obtained by replacing natural aggregates with blast furnace slag will be used in base layer of pavement. The reference mixture contains limestone aggregate. Laboratory tests will be conducted in the Laboratory of Roads from Technical University of Civil Engineering Bucharest; the results will be detailed in tables and graphs, the conclusions will make assessments on the ecological performance of asphalt mixtures. Thereby will be determined the performance of asphalt mixtures with different percent of slag versus natural aggregates using tests according European norms: air voids, Marshall Test, water sensitivity, stiffness. [ABSTRACT FROM AUTHOR]