New casting glass technique through the use of geopolymers

• Main Authors: Duran-Suarez Jorge, Villegas Maria-Angeles, Peralbo-Cano Rafael, Castro Gomes Joâo
• Format: Article
• Language: English
• Published: EDP Sciences 2019-01-01
• Series: MATEC Web of Conferences
• Online Access: https://www.matec-conferences.org/articles/matecconf/pdf/2019/23/matecconf_ricon17_03004.pdf

By using silicate inorganic binders and glass waste (colourless or coloured) it is possible to mould technical and artistic elements, which later can be hardened by means of high temperature processing. This procedure is controlled by both the glass transition temperature of binder and of glass waste used as aggregate. "water glass", catalysed with sodium hydroxide was used as a binder of glass shards from common industrial bottles, classified to a grain size distribution below 2 mm. Chemical analysis shows similarity of silica content between binder and aggregates of recycled glass, establishing as main differences in the percentages of chromophore oxides. In addition dilatometry curves of the two materials show close glass transition temperature values (575 and 598 °C, respectively), fact that facilitates sintering between binder and aggregates. The non-heat-treated samples present good compactness and mechanical resistance values, improved with heat-treatment at 700 °C. The high compactness of heated samples, showing rounded aggregate grains and softening of binder could let a good way for obtaining well-consolidated technical elements, made of recycled glass. From this test, it would be possible to use thermal ranges between 550 and 600 °C, as well as shorter exposure times for a proper hardening.