Evaluation of Utilizing Reclaimed Asphalt Pavement Materials in Warm Mix Asphalt with In-Place Recycling Method

Today, the greenhouse gas emission from industry and transport is the most important factors in the destruction of ecosystems and natural resources. One of the main sources of pollution is industries related to construction, maintenance and improvement of transport infrastructure. The production of cleaner asphalt needs to reduction of temperature in the asphalt mixture, without a reduction in mechanical performance levels. The reuse of Reclaimed Asphalt Pavement (RAP) in the production of new asphalt preserves natural resources and reduces environmental pollution. In this study, the use of RAP in producing hot and warm mix asphalt mixtures and effects of two additives (Sasobit and Zycotherm) was evaluated. The amount of RAP in the mixture was 50, and 75% and percentage of Sasobit and Zycotherm were 2 and 0.1% respectively. The addition of Sasobit improves the compressibility and strength of asphalt mixture effectively, so the sample containing 75% of RAP had better compressibility and strength, but Zycotherm caused improvement of compressibility and considerable decrease in air void range and increase stability of mixtures containing 75% RAP. Generally, partial strength values of WMA with 75% RAP is not very different from HMA. Finally, TSR test results have increased along with the increase in the percentage of sub-asphalt materials ratio which shows low sensitivity to moisture in the recycled mix.