Effect of Chemical Warm Mix Additive on the Properties and Mechanical Performance of Recycled Asphalt Mixtures

Abstract

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.

Feasibility of Pellet Material Incorporating Anti-Stripping Emulsifier and Slaked Lime for Pothole Restoration

“…Asphalt liquid emulsifier additives are typically combined with vegetable oils and mineral oils, such as castor oil, canola oil, soybean oil, corn oil, sunflower seed oil, olive oil, and grapeseed oil [48]. However, when using oil-based liquids for molding slaked lime, the resulting pellets are not structurally stable and easily crumble.…”

Sustainable Pavement Construction in Sensitive Environments: Low-Energy Asphalt with Local Waste Materials and Geomaterials

“…These techniques are the following [7]: (a) binder foaming processes, by injection of sprayed water on the previously heated bitumen, which causes the violent expansion of steam, foaming the bitumen and reducing its viscosity; (b) organic additives of low melting point (i.e., paraffinic resins, waxes with long aliphatic chains) that reduce the viscosity of the mixture; (c) microfoaming inorganic additives (zeolites); and (d) surfactant additives, which promote the coating and adhesion of the binder with the mineral aggregates, decreasing the surface tension of the hot bitumen and the friction between both components, thus enhancing the workability of the mixture during its production and compaction. A comparative life cycle assessment of WMA technologies can be found in some previous research [8]; and the effect of certain chemical additives on the mechanical properties of recycled mixtures has also been assessed [9].…”

Parameter Determination of the 2S2P1D Model and Havriliak–Negami Model Based on the Genetic Algorithm and Levenberg–Marquardt Optimization Algorithm

“…The viscoelasticity of polymer materials is caused by the deformation of the chain-like polymers under stress. With the widespread use of polymer materials in various engineering fields, an accurate assessment of the viscoelastic properties of polymers has become crucial for predicting their mechanical behavior [5,6].…”