Study on Styrene-Butadiene-Styrene Modified Asphalt Binders Relaxation at Low Temperature

Abstract

The paper presents the results of laboratory investigation on asphalt binders relaxation at low temperature, carried out in a ductilometer using the tensile test with continuous force measurement. Polymer modified asphalt binder samples consisting of a 50/70 penetration grade bitumen mixed with a concentrate of styrene-butadiene-styrene (SBS) modified bitumen—a 160/220 penetration grade bitumen modified with a SBS copolymer in the amount of 9%—were tested. Therefore, polymer modified binders containing 3%, 4.5%, 6% and 7.5% SBS, respectively, were obtained and investigated. Tensile tests were performed at −16 °C on samples before aging and subjected to short-term aging (RTFOT). Test results in the form of relaxation curves have been mathematically described using a modified generalized Maxwell model. Based on the acquired results, it was shown that the increase of the SBS copolymer content in asphalt binder precipitates the relaxation process, while aging slows down this phenomenon. It has also been proven that with increased content of SBS elastomer in asphalt binder, the effect of short-term aging on binder’s stress relaxation ability at low temperatures is reduced.

Development and Analysis of High-Modulus Asphalt Concrete Predictive Model

“…HMA mixtures were made with both unmodified and polymer-modified binders. Many research works concerning polymer-modified binders conducted previously by the authors were described in [ 23 , 24 , 25 ]. The gradation curves of aggregate mixtures used in each HMA are shown in Figure 1 .…”

Laboratory Investigation of Storage Stability and Aging Resistance of Slightly SBS-Modified Bitumen Binders

“…The content of SBS polymer is found to be one of the key factors that affects the properties of the obtained modified bitumen. In general, different SBS contents can result in different performances as well as modification mechanisms [ 13 , 14 , 15 , 16 ]. When the SBS content is 4–6%, a three-dimensional polymer network structure is formed in the modified bitumen and thus obviously improves the related properties [ 17 , 18 , 19 , 20 ].…”

Minireview on the Rejuvenation of Aged Styrene–Butadiene–Styrene (SBS) Modified Bitumen: State-of-the-Art and Outlook

“…Among them, aldehydes and ketones are formed during the oxidation aging of base bitumen, which is the main factor affecting the properties of base bitumen after aging. − Through evaluating the change of four fractions of base bitumen before and after aging, it can be found that base bitumen has a sequential reaction from aromatics to resins and then to asphaltenes. , For SBS modifiers, the first hydrogen atom connected with the carbon–carbon double bond functional group in the PB segment is easy to react with oxygen to form oxides because of its active chemical property. , Furthermore, given that the blocking effect of the side group of the benzene ring in the PS segment on the oxidation reaction of the main chain is weakened, SBS molecules react with oxygen to form hydroperoxides and then decompose to produce free radicals. , With the continuous oxygen aging, the chain reaction of SBS molecules goes on continuously, further resulting in the broken of the network structure . These physical and chemical changes of SBS modified bitumen directly result in the deterioration of properties, thus causing the occurrence of rutting, cracks, and other diseases of bituminous pavement. , …”

“…14 These physical and chemical changes of SBS modified bitumen directly result in the deterioration of properties, thus causing the occurrence of rutting, cracks, and other diseases of bituminous pavement. 1,15 Usually, the aged bituminous mixture is milled out during maintenance. In order to alleviate the negative impact of many milling materials on the environment and reduce the waste of bitumen and mineral materials, scholars and engineers generally try their best to reuse the aged bituminous mixture.…”