Influence of Guayule Resin as a Bio-Based Additive on Asphalt–Rubber Binder at Elevated Temperatures

Abstract

This study seeks to find the influence of replacing a portion of the asphalt–rubber binder with the bio-based material “guayule resin.” This replacement could be beneficial in terms of sustainability, economics, and environmental concerns related to the asphalt industry. Nine asphalt–rubber–guayule binders were investigated to find their rheological properties. Consecutively, the study proceeded with five selected binders being compared to the original asphalt (PG64-22). Investigations underwent whole matrices (crumb rubber modifier (CRM) residue included) and liquid phases (CRM residue extracted). Additionally, these properties were partially sought for their corresponding asphalt–rubber binders to compare and judge the contribution of the guayule resin. Likewise, a thermo-gravimetric analysis was done for the guayule resin to recognize its moisture and composition complexity. Such an analysis was also done for the as-received CRM and some extracted CRMs to determine the release and residue of rubber components. Outcomes showed that the guayule resin has the potential to compensate the performance required against the original asphalt at elevated temperatures while greatly decreasing the asphalt cement proportion. For instance, a blend of 62.5% asphalt, 12.5% CRM, and 25% guayule resin provided better performance than that of the original asphalt.

Component Analysis of Bio-Asphalt Binder Using Crumb Rubber Modifier and Guayule Resin as an Innovative Asphalt Replacer

“…The blends were created using a high shear mixer with an accurate heating assembly of a heating mantle and a temperature controller. As a part of the preparation process, the as-received guayule resin (coded G) was stirred at 160℃ for 4 hr with 600 rpm to make sure that no moisture or low molecular weight components were involved (coded G4), as verified in a previous study (Hemida and Abdelrahman, 2019a). The AC was mixed with CRM for 40 min at 190℃ and 3000 rpm.…”

Guayule resin: An innovative bioresource for asphalt cement replacement

“…In general, natural resins are amorphous hydrocarbons insoluble in water (7). Concerning the asphalt industry, guayule resin is an asphalt-like material (8). It is flexible adhesive, very susceptible to temperature change and viscoelastic at room temperature, liquid at high temperatures, and solid at low temperatures (8).…”

“…Concerning the asphalt industry, guayule resin is an asphalt-like material (8). It is flexible adhesive, very susceptible to temperature change and viscoelastic at room temperature, liquid at high temperatures, and solid at low temperatures (8). Hemida and Abdelrahman (8) reported that 25-50% asphalt replacement by guayule resin had the potential to provide better high-temperature performance than the conventional asphalt (PG64) but in case of using crumb rubber modifier (CRM) as an enhancer.…”

“…It is flexible adhesive, very susceptible to temperature change and viscoelastic at room temperature, liquid at high temperatures, and solid at low temperatures (8). Hemida and Abdelrahman (8) reported that 25-50% asphalt replacement by guayule resin had the potential to provide better high-temperature performance than the conventional asphalt (PG64) but in case of using crumb rubber modifier (CRM) as an enhancer. Likewise, it was evident that there was no liquid phase separation between asphalt and guayule with or without dissolved CRM but poor storage stability due to the CRM particle residue precipitation (9).…”

“…Nevertheless, there is a belief that guayule modifications could raise the temperature range. A blend of 62.5% asphalt, 12.5% rubber, and 25% guayule resin resulted in a 72.2℃ hightemperature grade (8). More details are provided in this study regarding low-and intermediate-temperature performance and attempts to link the mechanical behavior of guayule-based binders to the associated chemical changes.…”