Polysaccharides-Reinforced Bitumens: Specificities and Universality of Rheological Behavior

Abstract

The rheological properties of bitumens can be modified by the addition of specific chemical additives. Taking into account the molecular complex aggregation pattern, we hypothesized that macromolecules characterized by long, flexible, and hydrophilic chains can establish soft bridges connecting the different polar aggregates of asphaltenes, strengthening their overall hierarchical supra-structures, and consequently increasing rheological performance at higher temperatures. Here, we propose the use of low cost and high availability polysaccharides as chemical additives to improve the rheological characteristics of a bitumen and to strengthen its thermal resistance. Fourteen different low-cost and high-availability polysaccharides, (flours, gums, and extracts from vegetable products) have been tested. While alghae euchemae have proved to be the most effective additive, corn and 00 flours are the least effective. Attempts to explain their differences have been made considering their chemical interactions with the polar molecules of asphaltenes within the complex framework of their supramolecular hierarchical structures. Through Arrhenius analysis, a correlation between activation energy and preexponential factor has been found, which can be useful for practical purposes, together with an unexpected consistency with the behavior of simple liquids, despite the striking differences in structure. Furthermore, a qualitative model has been suggested. The added value of this work is the focus on polysaccharides constituting low-cost, high availability materials which are sometimes even found as waste in industrial processes, all factors which, together with the environmental issues connected with their use, can be considered for large-scale applications.

Functionalization and Modification of Bitumen by Silica Nanoparticles

“…These values are higher than those observed for the NH2@SNP-3 modified bitumen. The temperature dependencies of the elastic moduli and the loss tangent of bitumen modified by particles of C 14 N@SNP-3 in the amount of 1 wt% differ significantly [18,19]. It is worth noting that when 1% of C 14 N@SNP-3 particles are added, the elastic modulus curves decrease to a temperature of 70 • C, and at this temperature the loss modulus reaches a vertical asymptote.…”

Physical, Rheological, and Morphological Properties of Asphalt Reinforced by Basalt Fiber and Lignin Fiber

“…Secondly, the texture of LF is softer, so it is easier to blend into asphalt to make its property change and eventually enhance its stiffness and the deformation resistance. This can be ascribed by the fact that lignin fiber has a lot of polar groups, similar to the carboxyl groups and the phenolic hydroxyl groups [32], which contribute to the establishment of interactions with the asphalt molecules and their clusters, and the complex viscosity modulus is determined eventually by the force field between the molecules (the strength of the interactions involved in the intermolecular network in asphalt) [33]. As is mentioned before, BF can form a three-dimensional network structure and participate more in the softening point and ductility test process and disperse some part of the stress [28].…”

The Role of Additives in Warm Mix Asphalt Technology: An Insight into Their Mechanisms of Improving an Emerging Technology

“…Warm Mix Asphalt (WMA) technologies were developed to produce asphalt at temperatures slightly above 100 °C, with performances and characteristics equivalent to or even sometimes better than that of conventional HMA. WMA technologies mostly focus on the binder (bitumen) by adding different additives to improve its properties [ 3 , 4 , 5 , 6 , 7 ]. These technologies, which produce asphalt between 110 °C and 140 °C, facilitate proper coating of the aggregates and hence the workability and compactibility of the mix while also reducing production and compaction temperatures by 20–40 °C.…”