Behaviour of geogrid-recycled construction and demolition waste interfaces in direct shear mode

Over the last years the environmental sustainability has been demanding a progressive increase in the waste recycling in general and in the waste valorisation in construction industry, in particular. Some studies and applications of recycled construction and demolition wastes (C&DW) have been performed mainly related to the production of aggregates for use in concrete and in base layers of transport infrastructures. As regards the application of C&DW in geotechnical works, it has been verified that the valorisation is performed mainly in road construction, particularly in base and sub-base layers of the infrastructures. This paper presents preliminary results of physical, mechanical and environmental characterization of a recycled C&DW, as well as, the direct shear behaviour of recycled C&DW/geogrid interfaces. The results have evidenced that the C&DW, properly selected and compacted, exhibit similar shear strength to natural soils. The environmental characterization has not revealed any environmental concern. High values of the friction ratio were achieved, which supports the possibility of the use of these materials in geosynthetic reinforced structures. Nevertheless, this study is under development and further research is needed