Petroleum plant sap as an asphalt modifier for pavement applications

Abstract

This research work aims to contribute to the development of a bio-binder for use at the paving industry, from the modification of a petroleum based asphalt by the sap of Euphorbia Tirucalli (Petroleum Plant). Thus, a base asphalt (PG 64-28) was modified with 3%, 5% e 10%, by weight, of sap of the petroleum plant. The functional groups present in the sap were characterized by Fourier Transformed Infrared Spectroscopy. The parameters chosen for the analysis of the modified binders were the empirical characteristics (softening point, penetration); the rheological behavior (Brookfield viscosity, complex module, phase angle); and the effects of oxidative aging (all the properties before and after aging at RTFOT). It was also carried out specific rheological tests for the determination of Performance Grade (PG) and the behavior related to permanent deformation by Multiple Stress Creep and Recovery (MSCR) test. The results showed that it was possible to replace up to 10% of the asphalt binder by sap without observe significant changes in the rheological properties, and still reducing the compaction and mixing temperatures. This result implies on major environmental and economical effects, once a material from renewable source reduces the consumption of fossil asphalt binder, and decreases the fuel expenditure for the mixing and compaction procedures as well.