Optimized aerogel-filled glass bricks with repurposed aged flat glass

A novel type of glass brick, made from two packages of laminated annealed flat glass and a relatively deep cavity filled with aerogel granules, provides a balanced solution for meeting façade requirements related to thermal insulation, privacy and light transmission. Preliminary investigations on the structural performance of the prototype brick under thermal cycles highlighted the need for optimizing the connection between the plastic spacers defining the cavity depth, and the laminated glass. Moreover, it was recognized that this translucent glass brick would be a suitable application case for repurposing aged flat glass, even such with visible surface damages being eventually acceptable. This paper presents investigations on optimizing the assembly of the glass brick prototype for improved structural performance under thermal cycles. Tensile tests were performed on glass plates bonded by silicone adhesive joints to epoxy resin and polycarbonate blocks as spacer materials. Samples subjected to thermal cycles between − 25 °C and + 80 °C, and reference samples without undergoing thermal cycles were tested. All three investigated silicone adhesives showed worse adhesion on the polycarbonate substrates compared to the epoxy resin substrates. Additionally, repurposing aged flat glass for the glass bricks was evaluated, by developing a prototype and conducting preliminary experimental investigations on laminating aged flat glass by vacuum bag lamination. Finally, thermal simulations were conducted, showing that walls built with the optimized glass bricks can reach a U-value of 0.32 W/(m 2 ·K).