Search Results (2)

Utilizing polymers with asphalt mixtures is one solution to improving the performance of asphalt mixtures. Warm mixed asphalt (WMA) technology has begun to be widely used; however, hot mixed asphalt (HMA) is the most common paving procedure worldwide. HMA has some side effects, such as increasing emissions of exhaust gases, which lead to environmental pollution and air pollution and increasing energy consumption. Thus, utilizing WMA would help to improve asphalt mixture performance, reduce mixing and paving temperatures, reduce CO₂ emissions, and save energy. In this study, two WMA additives (Sasobit (M1) and Rediset LQ-1200 (M2)) are used with the control HMA to investigate and evaluate the asphalt mixture’s performance and the effects of WMA additives. Rediset LQ-1200 is a new version of materials classified under chemical additives in WMA. The Sasobit and Rediset LQ-1200 dosages were 1.5 and 0.5 percent by binder weight, respectively. Different mixture and binder tests were utilized, such as penetration, DSR, BBR, IDT, CML, HLWT, and APA. To simulate long-term performance, laboratory conditions of single or combined effects were used. The results showed that M2 had more cracking resistance and durable performance with low rutting resistance, while M1 had more rutting resistance and less moisture suitability, with low cracking resistance and durability. Full article

Newer technologies such as warm mix asphalt (WMA) and reclaimed asphalt pavement (RAP) have gained international approval and have been considered as appropriate solutions that support the sustainability goals of the highway sector. However, both technologies present some shortcomings. The lower mixing and compaction temperatures of WMA reduce the binder aging and the bond between the aggregates and the coating binder, thus resulting in less rutting resistance and higher moisture susceptibility. On the other hand, RAP mixes tend to be stiffer and more brittle than conventional hot mix asphalt (HMA) due to the effect of aged binder. This tends to increase the crack propagation distresses. In an attempt to overcome their individual shortcomings, this study investigated the new concept of a combined WMA-RAP technology. The chemical WMA additive Rediset LQ1102CE was utilized with mixtures incorporating low (15%), medium (25%), and high (45%) RAP contents. Dynamic modulus (DM) and flow number (FN) tests were conducted to investigate the effect of Rediset on the behavior of RAP mixtures. The dynamic modulus |E*| mastercurves were developed using the sigmoidal model and Franken model was used to fit the accumulated permanent deformation curve. The results of this study showed that Rediset addition improved the cracking resistance of RAP mixtures. However, the rutting resistance was reduced but kept within the acceptable range except for mixtures containing low RAP content. Full article