Wheel tracking rutting performance estimation based on bitumen Low Shear Viscosity (LSV), loading and temperature conditions

Abstract

The development of new technologies and road pavement materials require the evaluation of the asphalt mixture performance. Rutting is one of the main modes of failure of asphalt mixtures; it is typically studied at the laboratory through the wheel tracking test (WTT). Weather and traffic conditions (temperature, loads) significantly affect the pavement rutting performance. The bitumen rheological properties also have a main role in mixture rutting response; they can adequately characterized by the bitumen Low Shear Viscosity (LSV). The estimation of rutting performance appears as a useful decision tool to optimize pavement design process. This paper studies the rutting performance of asphalts mixtures utilising the WTT. The specimens were tested at different temperatures and loading levels to simulate different climatic and traffic pavement conditions. A performance estimator was developed including temperature and traffic load on the pavement, and LSV of the binder as input data.

Wheel tracking test (WTT) conducted under different standards. Study and correlation of test parameters and limits

“…Recently, the Rr limit of Agnusdei et al was verified considering the rheological properties of the binder such as low shear viscosity (LSV) in Morea et al [4,5]. In this work, drastic increases in Rr were observed when the original bitumen LSV was lower than 500 Pa.s at the same temperature as that of the WTT.…”

“…Furthermore, it was found that the mixtures studied showed drastic changes in rutting resistance when the asphalt binder achieved LSV values lower than 500 Pa.s. On the other hand, Morea et al [5] reported that the Rr value of 5 lm/min seems to be a turning point for rutting performance. This Rr threshold is related to the 500 Pa.s of the LSV limit.…”

“…In previous work Morea et al [4,5], rutting measurements in the WTT (according to BS 598-110) and the LSV of binders have been related. A relation between the mixture Rr and the LSV of the original binder, see Eq.…”

“…This LSV limit was approximately related to an Rr value of 5 lm/min in the BS 598-110 WTT. In addition, Morea et al [5] studied the variation in BS 598-110 by increasing the load from the standard procedure and related the mixture performance to the binder LSV. They found that, independently of the load level, 5 mm/min is the limit at which drastic increases in Rr are observed.…”

Influence of morphology on high-temperature rheological properties of bitumen modified with styrene-butadiene-styrene (SBS) copolymer

“…This is because the extrapolated curve may not present a plateau at very low frequencies but can be curvilinear in many cases. Thus, the common practice for studying PMB is to determine the LSV at a relatively low frequency instead [48][49][50], for example at 0.001 Hz (approximately 0.006 rad/s), which was used in previous studies [30,31].…”