چكيده به لاتين
Asphalt recycling is one of the ways to increase the efficiency of available funds and capital for use in maintenance and improvement of the road network, and to conserve natural resources and save costs. But in the process of producing hot mix asphalt using Reclaimed Asphalt Pavement (RAP), high temperatures cause hardening of bitumen and producing toxic gases that result in a lot of environmental pollution. Therefore, using warm mix asphalt technology, by reducing the viscosity of bitumen by different rejuvenator and additives, in addition to reducing environmental pollution and saving energy, better conditions for workers in the workplace are provided in terms of lower temperatures and less toxic emissions. Production of warm mix asphalt at lower temperatures reduces the amount of bitumen aging and improves the reduction of hardening due to oxidation of bitumen. This study seeks to investigate the use of two techniques to reduce the cost and effects of asphalt mix design on environmental pollution and improve asphalt performance. One is to use warm mix asphalt technique and another to use Reclaimed Asphalt Pavement (RAP) in asphalt mix design. The use combination of warm mix asphalt and high percentage of RAP is very important because of the environmental and economic benefits. In this study, Kaowax additive was used as WMA additive to reduce the mixing temperature. Also, RAP was used in different amounts (0%, 50% and 100% weight of mixed aggregate). The warm mix asphalt was produced at 115 ° C and therefore, less energy was used to make it than to produce hot mix asphalt. Also, due to the use of RAP, the amount of virgin materials was reduced. Parafiber were used to improve the properties of asphalt (0%, 0.06%, 0.12% and 0.18% of the weight of mixed aggregate). In order to compare and evaluate the performance of asphalt mixtures, resilient modulus test, dynamic creep test, moisture sensitivity test, fatigue test and Boiling Water test were performed. The use of RAP increases the resilient modulus, also improves the resistance to permanent deformation and the amount of whitening in the boiling water test. But it intensifies the moisture sensitivity of the asphalt mixture, but by adding Parafiber (0.06% the weight of mixed aggregate), the moisture sensitivity of the mixture can be improved. Also, according to fatigue test results, it was found that the by addition of RAP, the fatigue life of the mixture significantly decreases, but with the addition of Parafiber, fatigue life well improves.
