Guayule Plant: A Renewable, Domestic Source of Binder Materials for Flexible Pavement Mixtures.

摘要

The guayule (pronounced 'why-YOU-lee') plant grows in arid and semi-arid regions (e.g. the southwestern U.S.) and is a source of natural rubber. It was cultivated and processed during the World War II rubber shortage and is currently being processed primarily for the manufacture of hypo-allergenic latex (e.g. medical gloves, personal hygiene products). Depending on the process, many materials can be extracted from guayule. However, there are three basic products: rubber, resin, and bagasse. The rubber and resin (biopolymers) are of particular interest as they could prove to be renewable binder materials for flexible pavement mixtures. Limited preliminary testing showed that the resin could potentially be used as a recycling agent (viscosity modifier) when designing flexible pavement mixtures with a high percentage of reclaimed asphalt pavement (RAP), a small percentage of processed roofing shingles, and some virgin aggregate. The concept is to design a flexible pavement mixture produced with little to no virgin petroleum-based material. Due to the rising price of crude oil, flexible pavement costs have increased significantly. In regard to the concept, the potential impact on highway construction could be lower costs. A thorough experimental program is necessary to assess the limits of the use of the guayule rubber and resin in the context of this concept. Additionally, the guayule processing industry could benefit through the opening of another market for its products. Maybe more importantly, national security could be enhanced by decreasing the dependence on foreign oil.