Comprehensive Evaluation of Warm SMA Using Wax-Based WMA Additive in Korea

Abstract

Conventional stone mastic asphalt (SMA) is being increasingly used in highways and expressways because it provides high rutting resistance, good skid resistance, and noise reduction for heavily trafficked roads. However, the conventional SMA mixture requires high mixing and compacting temperatures to create a suitable coating between the polymer-modified asphalt and large size of aggregate. Warm-mix asphalt (WMA) technology is being extended to provide significant economic benefits when applied to heat sensitive mixture, such as polymer-modified mixture, to reduce mixing and compacting temperatures. In this study, the performance characteristics of SMA–WMA mixture using new polyethylene wax-based WMA additive were evaluated against the conventional SMA mixture without additive, in terms of the moisture susceptibility, viscoelastic properties, rutting resistance at high temperature, fatigue resistance, and crack resistance at low temperature. The mix design was carried out in the laboratory for the conventional SMA mixture, and a similar composition was adopted for the SMA–WMA mixture (with the incorporation of 1.5 % WMA additive in the asphalt binder weight), in order to evaluate the influence of the performance characteristics of the resulting SMA mixture. Drain-Down and Cantabro test results of SMA–WMA mixture meet the requirement of the relevant criteria. Compared to the conventional SMA, the mixtures containing WMA additive show superior performance in moisture susceptibility, rutting resistance at high temperature, fatigue resistance at intermediate temperature, and crack resistance at low temperature. Therefore, this implies that the WMA additive is effective in reducing the production temperature, without compromising the performance of the SMA–WMA mixture.

Investigation on the performance of polymer-modified stone matrix asphalt for bus rapid transport pavement

“…This study examined the adaptability of PSMA with a nominal maximum aggregate size (NMAS) of 13mm (13mm PSMA), and this is the popular combination through the blends presently utilized in BRT routes in Seoul, in order to support the sustainability pavement growth for the bus station. As a result of preliminary laboratory testing, it revealed that the 10mm PSMA demonstrated the highest plastic deformation resistance while maintaining other durability characteristics, thus, this mixture is the featured mix design used to release the burden on the conventional PSMA 13mm [6,7]. To achieve this goal, a multitude of experimental tests, comprising the dynamic modulus test and Hamburg wheel tracking test, were carried out to confirm the effectiveness of this combination.…”

“…The concept from earlier work [6,7] was employed to generate the aggregate's particle size for this investigation. The materials included lime filler, fine aggregate (0.075 -4.75 mm), and coarse aggregate with distribution sizes varying between 4.75 and 12.5 mm.…”

Evaluation of typical wma additives on design parameters of SMA mixtures

“…Authors determined viscoelastic properties, moisture susceptibility, fatigue resistance, rutting resistance at high temperature, and crack resistance at a low temperature of both samples. They reported that WMA variants demonstrated better performance in these performance parameters in comparison to conventional SMA variants (Kim et al, 2015). In addition, SMA-WMA is more environmentally friendly than conventional SMA in terms of economic competition (Leng, Al-Qadi, & Cao, 2017).…”

Development of Porous Asphalt with Bitumen Emulsion, Electric arc Furnace Slag and Cellulose Fibers for Medium Traffic Roads

“…They are therefore both essential elements for the production of a bituminous mixture suitable for traffic, and for durability. In both elements, important improvements have been made in this research to obtain a product of maximum quality, differentiable from the conventional one [34].…”