Electrical and mechanical properties of asphalt concrete containing conductive fibers and fillers

Abstract

Electrically conductive asphalt concrete has the potential to satisfy multifunctional applications. Designing such asphalt concrete needs to balance the electrical and mechanical performance of asphalt concrete. The objective of this study is to design electrically conductive asphalt concrete without compromising on the mechanical properties of asphalt concrete. In order to achieve this goal, various tests have been conducted to investigate the effects of electrically conductive additives (steel fiber and graphite) on the laboratory-measured electrical and mechanical properties of asphalt concrete. The results from this study indicate that the critical embedded steel fiber length is 9.6 mm to maximize the fiber's potential to bridge across the crack from single fiber tensile test. Both steel fiber and graphite can produce conductive asphalt concrete with sufficiently low resistivity, but steel fiber is much more effective than graphite to improve the conductivity of asphalt concrete. A combination of steel fiber and graphite can precisely control the resistivity of asphalt concrete over a wider range. Besides, asphalt concrete containing an optimized amount of steel fibers has a significant improvement in Marshall Stability, rutting resistance, indirect tensile strength, and low temperature cracking resistance compared to the plain concrete. The addition of graphite could increase the permanent deformation resistance with compromised stability and low temperature performance. Asphalt concrete containing steel fibers and graphite weakens the steel fiber reinforcing and toughening effect, but still has a significant improvement in mechanical performance compared to the plain concrete.

Electrically-conductive asphalt mastic: Temperature dependence and heating efficiency

“…It is worth noting that, all the weights presented in Table 2, were calculated with the aid of SG values provided in Table 1. According to literature, conductive fillers can be incorporated in asphalt-based materials by following either dry [7], [27], [28] or wet [29], [30] mixing method. In dry mixing method, all 19 the components including the conductive filler are mixed at a temperature range of 150-160°C 20 [7], [27], and in wet mixing method, the conductive fillers are first blended with bitumen at an 21 elevated temperature range of 170-180°C [29], [30], and then the modified bitumen is mixed 22 with other components.…”

Effect of metallic waste addition on the electrical, thermophysical and microwave crack-healing properties of asphalt mixtures

“…This enhancement has led to the development of innovative asphalt pavements with advanced thermophysical properties and energyharvesting purposes, that are used for solar collection [9], snow melting [10], and crack-healing by external heating [11][12][13][14][15]. García et al [16] and Wang et al [17] demonstrated the effectiveness of metallic fibres over other conductive additives in asphalt mixtures, concluding that their morphology and flexibility favour electrical and thermal conductivity [18].…”

Microwave Healing Performance of Asphalt Mixture Containing Electric Arc Furnace (EAF) Slag and Graphene Nanoplatelets (GNPs)

“…According to other studies [27][28][29][30], the electrical resistivity of the mixture slightly decreases with the additive content, until a critical value, called percolation threshold, where resistivity sharply decreases. The effect of adding slag or graphene on the electrical resistivity of the mixture is shown in Figure 12.…”

“…In the case of induction heating, electrical currents are induced by adding conductive particles in the composition of the mixture, and the heat is generated by the Joule effect [24][25][26]. Several additives and respective dosages were studied in order to maximize the conductivity of the mixture, such as steel wool, steel fibers, graphite, carbon black and carbon fibers [24,[27][28][29][30]. Another heating technique is microwave heating, that was found to be more effective than induction heating to heal cracks in asphalt roads [19].…”