Jordan Journal of Civil Engineering

Paper Detail

Examination of the Possibility of Using Gilsonite in Hot Mix Asphalt Concrete

Volume 13, No. 1, 2019
Received: 2018/11/26, Accepted:

Authors:

Siyab Houshmandi Khanghahi; Ahmet Tortum;

Abstract:

In hot mix asphalt concrete, bitumen is used as the adhesive and this material has a significant effect on the performance of mix asphalt. In order to improve the performance of the adhesive (bitumen), modifiers (additives) are used. In this study, gilsonite, as a part of bitumen and modifier, has been studied in order to improve the performance of mix asphalt. In this research, a nominal maximum size of 12.5 mm was chosen for the materials. In the first stage, in order to determine the optimum content for each component, three Marshall samples were produced and underwent Marshall tests. According to the Marshall test results, 5.9% was determined as the optimum bitumen content. In the second stage, samples from the optimum bitumen which were part of the gilsonite bitumen were produced and according to the test results, the sample containing 15% of gilsonite had the best performance. In the third stage, samples containing 0.5% more and 0.5% less amount of bitumen compared to the optimum bitumen content and 0%, 6%, 9%, 12%, 15% and 18% of gilsonite were produced and underwent the traditional Marshall and ultrasonic tests, where it was determined that the best performance belonged to the sample with 6.4% of bitumen and 15% of gilsonite. Also, in order to study the rutting of the mix asphalt containing gilsonite, samples with 0%, 6%, 12% and 18% gilsonite were produced and underwent dynamic creep test. The results showed that samples containing 12% and 18% of gilsonite had the least cumulative permanent strain and the highest stiffness modulus at 37.8°C and 54.4°C, respectively.

Keywords:

Hot mix asphalt, Optimum bitumen, Gilsonite, Dynamic creep, Marshall test