Evaluation of liquid rubber content and molecular weight on rheological properties of asphalt

Abstract

To evaluate the effect of liquid styrene‐butadiene rubber (LSBR) on the rheological performance of bitumen, LSBRs with molecular weights of 20,000 (LA) and 50,000 g/mol (LB) are blended into the virgin bitumen. The rheological effect regarding LSBR content and the molecular weight of the bitumen was then conducted by dynamic shear rheometer (DSR) test and a bending beam rheometer (BBR) test, respectively. Short‐term and long‐term aging tests were used to simulate the asphalt aging with modification of LSBR, and the variations of asphalts function groups were detected by Fourier Transform Infrared spectroscopy (FT‐IR). Results indicate that LSBR reduces the rutting and ageing resistance of the virgin bitumen. However, the blended LA and LB extensively enhance the crack resistance at low temperatures. Moreover, the LB modifier improves the fatigue performance of the asphalt more evidently, followed by LA, particularly at 2% mixing content (by weight of the virgin). Compared with LA, the added LB causes more deteriorating impact bitumen's rutting resistance, whereas LB increases the crack resistance at low temperatures. Of note, the LB‐modified bitumen exhibits less ageing sensitivity than the LA‐modified bitumen under a short‐term ageing simulation. However, the LA‐modified bitumen is less sensitive to the long‐term ageing test.

Evaluation of properties and aging resistance of epoxy asphalt composite modified by ultraviolet absorber

“…Under a long‐term service period, both asphalt and epoxy resin undergo various performance degradations under external environmental factors. These factors involve high temperature, sunlight (principally ultraviolet), oxygen, water, or a combination of these effects 6–11 . Herein, thermal‐oxidative aging affects the performance of EA binder, specifically increased modulus, reduced phase angle, and agglomeration of asphalt part 12–14 .…”

“…These factors involve high temperature, sunlight (principally ultraviolet), oxygen, water, or a combination of these effects. [6][7][8][9][10][11] Herein, thermal-oxidative aging affects the performance of EA binder, specifically increased modulus, reduced phase angle, and agglomeration of asphalt part. [12][13][14] These effects can be attributed to post-curing or oxidation in the binder.…”