Filigree exposed concrete façades with added glass particles, which glitter colourfully in the sun in accordance with levels of light exposure. Or high-grade, large sized floor slabs with eye-catching speckles of colourful glass: The integration of glass in concrete facilitates a whole new range of architectural design possibilities.
A real eye-catcher: Real glass in exposed concrete opens up new possibilities especially for façade design. (Photo: Betonbild)
Together with the University of Siegen and within the scope of a scientific project, Hering carried out research to try and find a method to produce a durable and stable concrete recipe with the addition of real glass. The difficulty involved in such a composition is due to the fact that an alkaline-silica reaction (ACR) occurs when glass is closely combined with the alkaline constituents in concrete. This is linked to a volume increase through which the concrete is prac-tically broken apart. The result is ultimately cracks in the concrete, which can strongly affect both the aesthetics and the serviceability and durability of the material.
Sample slabs: Within the scope of the project, standard-conforming concrete recipes were developed for the addition of yellow, green and blue recycling glass. (Photo: Betonbild)
Recycling glass suitable
Research findings prove that, due to their chemical composition, certain types of recycling glass react much less in combination with concrete than other types of glass. Thus, it soon became clear that concentration needed to be focussed on the application of recycling glass with regard to material testing at the University of Siegen. With success: Because during the series of experiments, the research team discovered the ideal mixing ratio - which means that eight types of tested glass were found to be suitable for practical application and fulfil the alkali guideline requirements. The special “concrete-glass recipe” developed by Hering also meets the criteria defined in DIN 1045 for load-bearing, prefabricated parts made of concrete. In addition to the aesthetic advantages, real glass provides considerably more intensive colour in comparison to other commonly used additives or imitation glass, and also has a valuable ecological aspect. The application of recycling glass ensures that valuable resources can be saved.
Further surfaces of Hering's architectural concrete
