Laboratory evaluation of microwave heating and skid resistance of pavement friction surfacing using calcined bauxite and magnetite aggregates

Abstract

A high friction surface treatment (HFST) with magnetite (MT) aggregates instead of conventional calcined bauxite (CB) aggregates as microwave absorbers were prepared in this paper. The deicing properties by microwave heating and long-term skid resistance of HFST with different proportions of CB and MT aggregate were evaluated. The deicing properties by microwave heating of HFST were determined by electromagnetic characteristics, heating surface temperature, and microwave deicing time (MDT) tests. The long-term skid resistance of the HFST was characterized by conducting dynamic friction coefficient and mean profile depth (MPD) tests after long-term polishing using a three-wheel polishing device. The results showed that the electromagnetic characteristics of HFST were enhanced greatly by the addition of MT. The microwave heating efficiency of HFST was enhanced by the increase of MT substitution rate, which further enhanced its microwave deicing efficiency. The microwave deicing efficiency of HFST with MT substitution rate of 25% was 1.4 times that of HFST with MT substitution rate of 0%. Long-term skid resistance of HFST was reduced by the addition of MT, however, HFST with MT substitution rate of 25% also maintained a terminal μ40 and μ60 above 0.7, which can provide higher friction comparable with other high friction aggregate such as taconite, basalt, emery and flint. To improve the deicing properties by microwave heating and maintain high skid resistance, 25% MT replacement rate in HFST is recommended.