Abstract
Since fatigue cracking is caused in the middle-temperature conditions due to the stresses from heavy traffic and as the bitumen plays a very important role in controlling this failure, therefore, in recent years, the production of the modified bitumen that can give a good performance in the middle temperatures has always attracted the interest of researchers. One of these bitumen modifiers is the styrene butadiene styrene (SBS) polymer. Due to the phase separation of bitumen and polymer, aging and oxidation, this polymer may not exhibit expected field performance at middle temperatures. Therefore, in this research, it is attempted to analyze the middle-temperature performance using the combination of nano-SiO2 and SBS polymer in the bitumen modification. In this paper, the addition of SBS and nano-SiO2 to the base bitumen resulted in the reduction of the complex modulus, phase angle, storage modulus and loss modulus at middle temperatures, thereby improving the potential of fatigue failure resistance. In general, considering the requirement for the rotational viscosity value up to 3 Pa.s at 135 °C and also, regarding the economic issues in choosing a lower percentage, the combination of 4.5% SBS + 3% nano-SiO2 is selected as the optimal composite.
Highlights
Bitumen is usually the byproduct in the crude oil production process, which, may not have all the specifications required for the production of asphalt mixtures [1]
TPhysical Properties he results of softening point, needle penetration, PI, ductility, rotational viscosity and rolling thin-film oven (RTFO) mass loss for various composites of Styrene Butadiene Styrene (SBS) and SBS/nano-SiO2 with base bitumen are given in Tab. (4)
These tests were selected for the purpose of fatigue analysis of the bitumen modified by SBS polymer and nano-SiO2 among the tests of physical properties of the bitumen
Summary
Bitumen is usually the byproduct in the crude oil production process, which, may not have all the specifications required for the production of asphalt mixtures [1]. Different modifiers are used to improve bitumen properties and behavior. The modification of bitumen with Styrene Butadiene Styrene (SBS) polymer improves the resistance to rutting, fatigue cracking, and low-temperature cracking [9,10], but involves the phase separation and is degraded under the ultraviolet light, as well as oxygen [11,12]. Research results show that modifying the polymer bitumen with nano-materials improves the high- and low-temperature performance, aging, oxidation and phase separation [13,14,3,4,5]. There are some limited studies on the effect of polymer nano-composites; this paper analyzes the middle-temperature performance of the SBS additive and the combined SBS and nano-SiO2 additive in 10, 15, 20, and 25 oC to the bitumen PG 64-16 as the most common bitumen in Iran. The bitumen performance, dual composite of bitumen and SBS, and triad composite of bitumen, SBS and nano-SiO2 were evaluated based on the softening point, needle penetration, ductility, rotational viscosity, RTFO mass loss, and dynamic shear rheometer (DSR) tests
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
