Biochar as a Highly Effective Asphalt Binder-Modifier

Background: Researchers at the University of Tennessee have developed a novel method to produce biochar as a more effective asphalt binder-modifier than commercially available activated carbon with high surface areas. In their study biochar was derived from organic plant matter via different types of pyrolysis and then tested as a bio-modifier for use in asphalt. Elements such as highest treatment temperature (HTT) pyrolysis method particle size of bio-modifier and modifier content were investigated in order to achieve the optimal modification effect. Moreover all of the carbonaceous additives were incorporated into one commonly used asphalt binder at different concentrations in order to obtain the optimal content. The study utilized a commercially available active carbon (with very high surface areas) as a reference additive and systematic studies were performed on the modification effects of every sample to derive a comprehensive evaluation. Technology Description: The evaluation showed that the biochar bio-modifier which was developed by a novel method is capable of changing the rheological properties of the asphalt binder. Thus it improved its performance against pavement distresses. In addition the bio-modifier increased viscosity of the asphalt binder at high service temperatures while showing negligible effects at low service temperatures. It also significantly increased the rutting resistance of the asphalt binder. Finally when testing the fatigue and cracking resistance it was shown that resistance remained unchanged with up to 10% addition of biochar but decreased with the addition of commercially available activated carbon. Therefore biochar appears to be a more effective binder-modifier than commercially available activated carbon within addition of 10 wt. % Applications: Bio cells