Summary of Rilem Technical Committee TC 279-WMR Activities

Several alternative paving materials, namely plastic, crumb rubber, steel slag, and construction and demolition waste, were incorporated into the construction of road pavements, highlighting their favorable environmental and economic outcomes. Despite the considerable demand for such sustainable practices, the effort is mainly confined to research activities and within a limited number of countries, preventing further advancements and broader validation capable of reaching full acceptance at the market level for alternative road materials. RILEM TC 279-WMR "Valorisation of Waste and Secondary Materials for Roads" sought to promote the adoption of these alternative paving materials based on inter-laboratory activities addressing the behavior of the bituminous blends designed with marginal materials aiming to define tailored methodologies targeting selection, preparation, and use at the production level. Experimental results indicate that using alternative materials can result in similar performance compared to the corresponding virgin materials, keeping in mind that mix designs might need to be adjusted, for example, using higher binder content. In addition, adopting appropriate test procedures is essential as such new composite can be susceptible to specific failure modes or scale effects. Furthermore, despite the mechanical performance, environmental and life cycle assessments need to be evaluated to ensure that such materials are sustainable and valuable.