PNNL

Abstract

This paper assesses the potential of bio-binders as sustainable alternatives for pavement construction in cold regions. It specifically examines the physicochemical and rheological properties of bio-binders and their potential to offset carbon emissions when used as partial replacements for conventional petroleum-based asphalt binders. The findings indicate that incorporating bio-binders does not compromise the structural integrity of asphalt; rather, their inclusion enhances material flexibility and reduces the risk of thermal cracking. Notably, adding 6 wt.% of a bio-binder derived from Wild-type Ulva, significantly improves the asphalt's self-healing abilities and its resistance to fatigue cracking. The study further shows that specific bio-binders enhance the stress-relief capacity of asphalt mixtures, which helps minimize stress accumulation and improves resistance to low-temperature cracking. In some instances, elastic recovery under repeated loading increased from 0.1% to 71%, with the blend of Haematococcus pluvialis bio-oil demonstrating the most promising results. Additionally, from an environmental perspective, using biomass-derived binders leads to a substantial reduction in carbon emissions. For every 1% of bio-binder added, net emissions decrease by approximately 3%. This indicates that a 33% blend could potentially achieve carbon neutrality, while blends that exceed 33% may even result in net-negative emissions. As a result, bio-binders present a promising solution for improving both the resilience and sustainability of asphalt pavements, particularly in cold climates. With careful selection and optimization, they provide a viable pathway toward more durable and eco-friendly infrastructure.