Shaping transparent sand in sand

Abstract

This research investigates the potential of 3D printed sand moulds for casting structural glass column having optimised cross section. Conventionally, Glass, in architectural industry, has been used in form of sheets (Float glass) due to ease of fabrication of planar sheets, but in last few years, cast glass bricks have been used for creating structural wall/ envelope of few architectural projects namely, Atocha memorial (Spain), Optical house (Japan) and crystal house (Amsterdam) due to its high compressive strength. Cast glass offers many advantages over float glass, but, the reason for limited use of it, in the industry is due to annealing time. Thicker the section of glass, more time is required to anneal the element. To reduce this annealing time, one of the most promising solutions is to use an optimised geometry composed of thinner sections. These optimised geometries usually are based on stress and buckling load of the element; hence they have very dynamic geometry. In order to fabricate these optimised geometries, one has to take help from digital manufacturing tools involving additive manufacturing (3D printing). 3D printing of glass is still in very primitive stage and is currently used for creating artefacts rather than structural elements. Another alternative to fabricate these complex geometries is to print the moulds and then cast glass. 3D printed Sand moulds are being used in the industry to cast optimised concrete slabs and steel nodes. Hence this research explores the feasibility of 3D printed sand moulds for casting optimised structural glass geometries. A column design as a case has been taken, for the experiment as glass having high compressive strength, comparable to steel, portrays as a perfect material for a compression only structure. The column is structurally optimised using topological optimisation and sections of the complex challenging optimised geometry are fabricated using 3D printed sand moulds as different scale and results are drawn.