Evaluation of the rheological effect of asphalt binder modification using Linum usitatissimum oil

Abstract

Warm mixtures are an essential alternative for paving as they minimize costs and environmental impacts, and their performance is similar to hot mixtures. This research evaluated the effect of adding linseed oil obtained from Linum usitatissimum in the contents of 1, 2, 3, 4, 5, and 6% by weight on the physical and rheological properties of the asphalt binder. The asphalt binder was evaluated through tests of penetration, softening point, rotational viscosity, performance grade (PG); these tests were performed before and after the short-term aging procedure; multiple stress creep and recovery (MSCR), and linear amplitude sweep (LAS). It has been verified that the mixing temperature could be reduced by up to 15 °C for the 6% linseed oil content, but it was lost in terms of performance, level of supported traffic, and fatigue life. In the so-called ideal content found, 4% linseed oil, there is a reduction in the mixing temperature of around 10 °C, as well as a maximum temperature of PG, 58 °C, it reduces by only one step compared to the pure binder, 64 °C, in addition to presenting the second-longest fatigue life of the grades studied, being classified as ideal for standard traffic by the MSCR test. Linseed oil proved to be an excellent green alternative for the production of warm mixtures.