Performance Evaluation of Asphalt Mixture with Nanosized Volcanic Ash Filler

Volcanic ash has been found to be able to improve the performance of asphalt mixture. To understand the mechanism of action of the nanosized volcanic ash fine filler on asphalt mixture and find proper types of volcanic ashes for practical application, this paper selects typical types of volcanic ashes, which have significant variation in nanoscale inner pore structure and particle size for comparison. Two sets of experiments have been carried out with some modifications to the standard test procedures. The first set was full temperature range dynamic shear rheometer tests carried out on the mastics with typical volcanic ash fillers or general mineral filler. Based on the results of the mastic tests, the second set was dynamic modulus tests and three-point bending tests were conducted on the mixtures to further discuss the validity of volcanic ash filler in asphalt mixture and evaluate the high-and low-temperature performance, respectively. The testing results elucidated that volcanic ash filler with the addition of styrene-butadiene-styrene (SBS) modifier can improve both high-and low-temperature performance of asphalt mixture. Besides, the three-point bending test results not only show the improvements on the modulus, but also on strength and ultimate strain of the mixtures, which will influence the low-temperature cracking resistibility more directly. (C) 2018 American Society of Civil Engineers.