Experimental Characterisation of Translucent High-Performance Concrete Tiles Incorporating Recycled Glass for Architectural Envelopes

The construction sector faces environmental challenges related to material consumption, waste generation and energy efficiency. In this context, light-transmitting concrete tiles incorporating recycled glass offer a favourable solution for the construction of lightweight building envelope systems combining circularity, functional performance and design value. This research project developed novel self-compacting high-performance concrete tiles integrating coarse waste-glass aggregates to develop translucent components for use as solar filters. To the authors’ best knowledge there is a gap in the market regarding this type of envelope. Three concrete mixtures were developed, including the reference mix and two waste-glass-based mixtures with different glass contents, colours and nominal size distributions. Concrete tiles with thicknesses between 4 and 20 mm were analysed regarding their overall physical, mechanical, durability and luminous performance. This research paper’s conclusions confirm the suitability of recycled glass concrete tiles for facade applications and support the selection of the minimum viable thickness as a design approach. An optimal thickness of 8 mm was determined, providing the optimal balance between translucency (8–4% light transmittance), structural behaviour (flexural strength > 7 MPa) and durability performance (mass losses < 2.34%). Improving the mechanical performance of slender elements by increasing both the contribution of fibres and matrix–waste bonding are among the future follow-up steps.