New circular building composite material to upcycle building wastes

A new circular composite material for building applications is developed, made of two recycled raw materials, paper and sand. Hydraulic lime is added as binder. This new composite targets a low environmental impact thanks to benefits of upcycling buildings waste, a low energy production process, a lifetime up to 60 years and a high potential of reversibility, reuse and upcycling. The research has focused on mechanical and physical properties and an analysis of the microstructure by X-ray 3D microtomography and in-situ compression test. The mechanical and physical testing have shown good and unexpected properties: a density of 330 to 1300 kg/m³; a compressive strength between 0,12 and 4,3 MPa, a bending strength of 0,14 to 2 MPa, a thermal conductivity of 0,08 to 0,14 W/mK and a high sound reduction index. Further research will focus on construction and environmental aspects such as the applications at 1/1 scale, a life cycle analysis and a material passport for the manufacturer. Following the result obtained, three applications will be developed: a partition panel with adequate impact and acoustic resistance, a dry screed slab and a self-supporting block, both with proper thermal, acoustic and mechanical performances according the standards of the building sector.