Study on Workability and Skid Resistance of Bio-Oil–Modified Fog Seal with Sand

The objective of this study is to evaluate different fog seal materials, including Tianjin BEST - micro-seal bonding reductant (BEST-MBR), American MasterSeal, and a newly designed bio-oil–modified fog seal with sand (BFSS) using various sand contents. The workability of all materials was tested based on the fluidity test, seepage performance test, and the indoor skid resistance test. A new method to evaluate the surface texture of solidified fog seal with sand (FSS) material was performed based on the aggregate image measurement system II. The test results show that when the seepage flow evaluation index is set to a 1.5-mm seepage width, the seepage flow value should not be less than 0.2, whereas when the width is 2 mm, the flow value should not be less than 0.7. In addition, the surface texture evaluation indicates that some smaller grooves are formed around the sand particles after the BFSS is solidified and the structural depth of the material surface is increased. The BFSS material with 20 % sand content is slightly better than the BEST-MBR in terms of skid resistance, whereas it is still lower than MasterSeal. The addition of bio-oil lowers the need for asphalt binder, leading to energy savings. Thus, BFSS is a relatively desirable FSS material.