Evaluation of bio-based fog seal for low-volume road preservation

Abstract

<p>While asphalt pavement is common in the United States, it is susceptible to oxidation as being exposed to environmental effects, resulting in the surface deterioration. To maintain the performance of a road surface and extend its service life, traditional fog sealers such as asphalt emulsion are used to mitigate micro-cracking, prevent oxidation and reduce water infiltration. Due to the relatively high cost and environmental concerns of petroleum-based sealants, the use of bio-based products as fog sealers has attracted more and more attention. Some new bio-based sealants derived from agricultural oil have been used as fog sealers in many states. To evaluate the effectiveness of a bio-sealant as an alternative to preserve asphalt pavements, a 5.3 km test section was selected for application of a soy-based fog sealant with three different application rates to conduct a two-year investigation of pavement marking retroreflectivity, surface friction, growth rate of cracking, laboratory water absorption, and air permeability. A control section without bio-sealant was also set up for comparison purposes. The field results revealed that, after application, a short-term decrease in retroreflectivity and skid resistance was restored to the original condition after two weeks and several months, respectively. The treated sections also exhibited a better control of growth rate of cracking than that of control section. The laboratory results indicated that the bio-sealant treated specimens applied at the highest application rate exhibited the lowest water absorption and air permeability. Such findings indicate that bio-sealant can be a sustainable preservation alternative for asphalt pavement.</p>