Document Type : Research Paper
Authors
1
Department of Civil and Environmental Engineering, Amirkabir university of technology, Tehran
2
\Professor, Head of Department of Transportation, School of Civil Engineering, K.N.Toosi University of Technology, Tehran 1996715433, Iran
Abstract
Efforts to mitigate and control global warming have led to the consideration of warm-mix asphalt technology in the asphalt industry. Warm mix asphalt, compared to hot mix asphalt, offers advantages such as reduced energy consumption and lower production of toxic gases. However, it does have certain weaknesses, including susceptibility to moisture and premature rutting. Therefore, it is crucial to develop warm mix asphalt mixtures with excellent mechanical performance. One potential solution is to carefully select the appropriate filler. The objective of this research is to examine and explore the impact of limestone powder, cement, fly ash, and micro lime as fillers on the performance of warm mix asphalt mixtures. Additionally, an organic additive called Ethylene bis estearamide was utilized to create the warm mix asphalt mixture. To evaluate the mechanical performance of the asphalt mixture, various tests were conducted, including indirect tensile strength tests, dynamic creep tests, and semi-circular bending tests. In the indirect tensile strength test, the force required to break the samples was measured under a constant loading rate of 50.8 mm/min. In the dynamic creep test, the sample was subjected to a haversine loading of 200 kPa at a temperature of 40 degrees Celsius. In the semi-circular bending test, the energy required to fracture the sample at -22 degrees Celsius was calculated. When making a warm mix asphalt mixture using Ethylene bis stearamide additive, although it increased resistance to rutting by 10%, it reduced resistance to low-temperature cracking by decreasing fracture energy by 7%. The semi-warm asphalt mixture containing fly ash with a TSR equal to 80% exhibited good moisture resistance. The addition of cement increased resistance to rutting by 25%. The use of micro lime improved moisture sensitivity, resulting in a 140% increase in rutting resistance and a 17% increase in fracture energy.
Keywords
Main Subjects
)