This study evaluates the influence of polymer-modification on the induction heating capability of asphalt mastic in a microwave field, and investigates how effectively this approach can be utilized for ice melting and self-healing purposes. To this end, different asphalt mastic mixtures with different polymer-modification and mixing procedures were tested under microwave field exposure for induction heating capability, ice-melting ability, and self-healing capacity. The mixtures were made through warm-mix and hot-mix procedures with four bituminous binders, including virgin (unmodified) asphalt and the same binder modified with three types of polymers. The results showed the effectiveness of microwave induction heating of asphalt mastic for both crack-healing and deicing purposes. The binder type was found to influence the ice melting and crack healing rates, such that using a warm-mix asphalt binder resulted in a more efficient heat generation and conduction than using a virgin asphalt binder. While polymer-modification undermined induction-heating, ice-melting, and self-healing performances, SBS-modified asphalt binders exhibited better performance than the other polymer-modified binders.

Electrically-heated pavements have attracted attention as alternatives to the traditional ice/snow removal practices. Electrically conductive polymer-carbon composite coatings provide promising properties for this application. Based on the concept of joule heating, the conductive composite can be utilized as a resistor that generates heat by electric current and increases the surface temperature to melt the ice and snow on the pavement surface. This research investigates the feasibility of applying an electrically conductive composite coating made with a Polyurethane (PU) binder and micrometer-scale carbon fiber (CMF) filler as the electrical heating materials on the surface of Portland cement concrete (PCC) pavements. PU-CMF composite coatings were prepared using different volume fractions of CMF, applied on the PCC surfaces, and evaluated in terms of volume conductivity, resistive heating ability, durability, and surface friction properties at the proof-of-concept level. A conceptual cost analysis was performed to compare this method with other heated pavement systems with respect to economic viability. Percolative behavior of CMF in PU matrix was captured and most desirable CMF dosage rates in terms of each performance parameter were investigated. Two percolation transition zones were identified for CMF in PU matrix at dosage rate ranges of 0.25-1% and 4-10%. The composites exhibited their most desirable performance and properties at CMF dosage rates greater than 10% and smaller than 15%.

Conventional snow removal strategies add direct and indirect expenses to the economy through profit lost due to passenger delays costs, pavement durability issues, contaminating the water runoff, and so on. The use of superhydrophobic (super-water-repellent) coating methods is an alternative to conventional snow and ice removal practices for alleviating snow removal operations issues. As an integrated experimental and analytical study, this work focused on optimizing superhydrophobicity and skid resistance of hydrophobic coatings on asphalt concrete surfaces. A layer-by-layer (LBL) method was utilized for spray depositing polytetrafluoroethylene (PTFE) on an asphalt concrete at different spray times and variable dosages of PTFE. Water contact angle and coefficient of friction at the microtexture level were measured to evaluate superhydrophobicity and skid resistance of the coated asphalt concrete. The optimum dosage and spay time that maximized hydrophobicity and skid resistance of flexible pavement while minimizing cost were estimated using a multi-objective Bayesian optimization (BO) method that replaced the more costly experimental procedure of pavement testing with a cheap-to-evaluate surrogate model constructed based on kriging. In this method, the surrogate model is iteratively updated with new experimental data measured at proper input settings. The result of proposed optimization method showed that the super water repellency and coefficient of friction were not uniformly increased for all the specimens by increasing spray time and dosage. In addition, use of the proposed multi-objective BO method resulted in hydrophobicity and skid resistance being maximally augmented by approximately 23% PTFE dosage at a spray time of 5.5 s. Highlights Effects of spray time and dosage on the hydrophobicity and friction of asphalt were investigated. A layer-by-layer method was utilized for spray depositing polytetrafluoroethylene on an asphalt concrete. The optimum dosage and spay time were estimated by using a multi-objective Bayesian optimization method. An acquisition function that can tackle problems involving multiple objective functions was proposed. The optimum hydrophobicity and skid resistance were achieved with 23% PTFE dosage and at a spray time of 5.5 s.