Using of Circular Road Simulator to Evaluate Performance of Asphalt Mixtures made of Industrial By-Products

It is well known that the use of by-products (recycled), instead of natural materials help toward more environmentally friendly roads by easing landfill pressures and reducing demand of extraction. Correspondingly, this paper deals with evaluating the mechanical performance of new developed hot mix asphalt (HMA) mixtures made of alternative materials (up to ۹۸% industrial waste materials). The paper sheds light on the long-term performance of the new developed mixtures using the accelerated load testing facilities available at VTI (the Swedish National Road and Transport Research Institute). The materials, methods and results given in this article are part of ALTERPAVE European -project findings. In this project, different types of industrial by-products, namely, reclaimed asphalt pavement (RAP), foundry sand and steel slag) have been used in different fractions to find the composition of the best asphalt mixtures made mainly of industrial wastes that can substitute the asphalt mixtures made of natural aggregates. Using the circular road simulator (CRS), twenty- eight asphalt slabs were prepared using natural and industrial by-products and tested under different testing conditions. The CRS test has been used to assess the surface deterioration, wear and the changes in macrotextures of the tested asphalt slabs under wheel loading in dry or wet conditions and under different testing temperatures to simulate summer and winter seasons. In addition, studless and studded tires have been used to traffic the asphalt slabs during the CRS testing to simulate the current roads conditions in different European countries. The test results demonstrated that by controlling the homogeneity of recycled material and by using rejuvenators of suitable quality and quantity, it is possible to obtain paving mixtures with high content of recycled materials that can satisfactory substitute the conventional asphalt mixtures made of natural materials.

Keywords:

Accelerated load testing , Foundry sand , Hot mix asphalt , Reclaimed asphalt pavement , Steel slag