Influence of Crumb Rubber Concentration on the Rheological Behavior of a Crumb Rubber Modified Bitumen

Abstract

Bitumen is widely used in construction. Its applications go from binder for road asphalts to built-up roofing membranes and other waterproofing uses. The use of crumb tire rubber as a binder modifier may contribute to solving a waste disposal problem and to improving the quality of road pavements. This paper deals with the effect that rubber concentration exerts on the thermorheological properties of rubber-modified bitumens. The results obtained confirm that the rheology and storage stability of these modified binders are largely dependent on rubber concentration. The linear viscoelastic measurements carried out revealed an improvement of both low and high in-service properties of the binder. The viscous flow measurements showed an important increase in viscosity and a noticeable reduction in temperature susceptibility. A swelling process of the crumb rubber by light components of the maltenic fraction was confirmed by modulated differential scanning calorimetry (MDSC). The stability tests, performed on samples stored at 180°C, demonstrated that the storage stability of rubber-modified bitumen was improved as rubber concentration increased.

An investigation on using pre-treated tyre rubber as a replacement of synthetic polymers for bitumen modification

“…The master curves show that rubber modification has resulted in a significant increase in the complex modulus at low frequencies (equivalent to high temperature response) and consequently the RTR-MBs can be expected to have enhanced rutting behaviour. This increased stiffness can be attributed to the dominance of the rubber (polymer) network formation which is stiffer and more elastic than the viscous phase of the base binders , Navarro et al 2005. However, the rubber modification is less effective within the base bitumen dominant areas (low temperatures and high frequencies) and the curves tend to come together, apart from the RTR-MBs processed with TRSE and "S" bitumen.…”

Rubberised bitumen manufacturing assisted by rheological measurements

“…has resulted in a significant increase in the complex modulus at low frequencies (equivalent to high temperature response) and consequently the RTR-MBs can be expected to have enhanced rutting behaviour. This increased stiffness can be attributed to the prevalence of the rubber (polymer) network formation which is stiffer and more elastic than the viscous phase of the base binders (Airey, Singleton et al 2002, Navarro et al 2005. However, the rubber modification is less effective within the base bitumen dominant areas (low temperatures and high frequencies) and the curves tend to coincide at high frequencies, particularly for the RTR-MBs processed with "H" bitumen.…”

Dynamic Monitoring of Rubber Asphalt Production Quality Based on HOPLS

“…It is reported that with the powder dosage increasing, the rubber asphalt temperature sensitivity is getting steadily worse based on Brookfield viscosity in [7][8].…”