Early pavement distress caused by heavy traffic is frequently observed on bridges with relatively thin decks of orthotropic design, particularly in hot climates. This study investigates the possible use of epoxy asphalt to stiffen the thin deck/pavement composite, minimise deflection and ultimately fatigue failure. Three different epoxy asphalt binders were used and two pavement mix designs were employed. The binder and pavement mixture properties were evaluated by direct tensile and pull-off strength test on the binder, Marshall test of the paving mixture and flexural fatigue tests of paving mixture on steel plates. Test results show that a relatively high modulus binder and a relatively stiff pavement can effectively reduce the composite’s deflection and improve fatigue resistance on a relatively thin steel plate. Binder adhesion to the aggregate in the composite seems to play a pivotal role and the strength of this bond may have a close relationship with the stiffness of the pavement.

The average content of reclaimed asphalt pavement (RAP) materials in asphalt mixtures for new pavements is around 22% in the current paving practices in the United States. Increasing this content has significant economic and environmental benefits. This study explored the approach of producing asphalt mixtures with 100% RAP materials by adding a small percentage of epoxy asphalt. Specimens of 100% RAP mixtures with low contents of epoxy asphalt were fabricated and evaluated in the laboratory for their properties related to pavement performance, including Marshall stability and flow, indirect tensile strength, resistance to moisture damage, resistance to fatigue damage, and fracture resistance. The results showed that the specimens made of 100% RAP materials selected in this study without a new binder or rejuvenator had low workability and high Marshall stability and indirect tensile strength but poor resistance to moisture damage and fatigue damage. A low percentage (0.5 to 2%) of epoxy asphalt significantly improved the resistance to moisture and fatigue damage of the 100% RAP mixture, and this improvement increased with the epoxy asphalt content. The fracture resistance of the 100% RAP mixture was also significantly improved by a low dosage of epoxy asphalt at a low temperature (8 °C), but the improvement was less significant at a moderate temperature of 25 °C.

Epoxy asphalt is a thermosetting paving material that can provide higher strength, stiffness, adhesion, high-temperature stability, and service life compared to conventional asphalt; however, it has not been widely used on highway pavements, primarily due to the higher initial cost and limited operational window. In this paper, dilution of epoxy asphalt with styrene-butadiene-styrene (SBS)-modified asphalt was studied for the potential use in chip seal applications. Performance characteristics such as workability, hardening process, uncured and fully cured bond strength, and fully cured binder performance in both high and low temperatures were also investigated thoroughly. It was found that the SBS-modified asphalt has a higher initial adhesion feature and can help provide a quicker opening to traffic after construction than the undiluted epoxy asphalt. Meanwhile, epoxy asphalt binder in the blend can enhance the final adhesive strengths to retain the chips under strain induced by vehicles in the long term. The dilution level in $1:0.5$ and $1:1$ ratios showed a faster polymerization/curing rate than the $1:2$ and $1:3$ ratios. Diluted epoxy asphalt also showed improved low-temperature performance compared to undiluted epoxy asphalt and better high-temperature performance compared to pure SBS-modified asphalt. Overall, this paper presents that dilution of epoxy asphalt with SBS-modified asphalt could have significant practical benefits, and the $1:1$ dilution ratio seems to be the most suitable from the aspects of performance, cost, and practical use.

With the focus of language teaching from teachers to students, the personal factors of language learners have become the focus of research. In 1964, Kagan and his colleagues proposed a reflective-impulsive cognitive style(R-I), a pair of opposing cognitive style that can be measured by Matching Familiar Figures Test (MFFT). Kagan believes that in dealing with cognitive tasks, holding a slow but accurate style is a reflective cognitive style, and holding a fast but inaccurate style is impulsive cognitive style. What’s more, different cognitive styles of learners affect language learning. For English learners, oral English is connected with the output of language, and students' oral ability is an important part of pragmatic competence. The researcher uses MFFT20, combined with observation, interview, oral test to evaluate the oral performance and ability of 80 high school students in a middle school in Chongqing. By analyzing the correlation between the reflective-impulsive cognitive styles and oral English ability, the following results are obtained. First, reflective cognitive style and impulsive cognitive style account for the same proportion of students. And reflective-impulsive cognitive style affects the oral ability of English learners. Second, students with different cognitive styles have great differences in oral performance. Third, generally speaking, English learners with reflective cognitive style perform better in oral accuracy than English students with impulsive cognitive style, while English learners with impulsive cognitive style perform better in oral fluency than students with reflective style.