RILEM TC 279 WMR round robin study on waste polyethylene modified bituminous binders: advantages and challenges

Abstract

A. (2022). RILEM TC 279 WMR round robin study on waste polyethylene modified bituminous binders: advantages and challenges. Road Materials and Pavement Design.

Dry Addition of Recycled Waste Polyethylene in Asphalt Mixtures: A Laboratory Study

“…It is worth noting that all values fell within the acceptance limits, therefore, the tests can be considered as reliable and data can be consistently adopted. Moreover, similar variabilities were found for the REF and PE-modified mixes, suggesting that PE particles within mixtures did not cause great inhomogeneity, in contrast with the heterogenous results observed at the binder scale [ 11 , 12 ].…”

“…In this framework, more than 10 laboratories worldwide participated in the interlaboratory test program mainly aimed at evaluating the rheological and damage properties of the PE modified binders. The results collected during the above-mentioned comprehensive study [ 11 , 12 ] highlighted encouraging evidence toward the systematic use of waste PE as an effective additive to improve the asphalt binder performance, especially at high service temperatures, provided that waste PE is ground to small particles (around 1 mm maximum size) to enhance the blending with bitumen. However, several issues have been identified in terms of the heterogeneity and variability of the test results.…”

“…To accomplish this objective, a comparative laboratory study was carried out on dense graded asphalt mixtures containing different amounts of waste plastics (i.e., 0%, 0.25%, and 1.5% by weight of the mixture). A total of 0% plastic waste (i.e., no plastic addition) was selected as a reference mixture for comparison purposes whereas 0.25% plastic corresponded to 5.0% PE by bitumen weight (i.e., the amount used in the previous phase of the research for wet modification of the bitumen [ 11 ]). On the other hand, 1.5% PE by weight of mixture was chosen to reproduce a typical amount of “dry additive” into the asphalt mixes.…”

Rheological Behaviors of Waste Polyethylene Modified Asphalt Binder: Statistical Analysis of Interlaboratory Testing Results

“…7,8 Among these material sources, PE is one of the most commonly used. 9,10 Regarding the incorporation methods, dry and wet processes are widely used. In the wet process, waste plastic is incorporated directly into the binder by 0.5% to 10% weight of the binder at high temperatures.…”

“…12 However, previous studies frequently observed scattered rheological responses at relatively high temperatures. 9,10,13 This inconsistency can be mainly attributed to the difference in density, viscosity, and incompatibility between recycled waste PE and binder. 12 Hence, the high temperature rheological behavior of PE modified binders needs to be carefully studied.…”