Structural behavior of ice composite for 3D printing

3D printing with ice composites is an entire new field. It could be applied for Mars missions by using Robots with locally available material such as ice and soil. Another application is 3D printing for sculptures. The third application is 3D printing for temporary structures in artic areas. The problem of using ice for construction is its brittleness. It is possible to reinforce ice with additives. Just as concrete or polymers can be reinforced with steel rods or fibers, ice can be reinforced with soil, silica, wood, paper fibers or polyphenol alcohol. The fibers increase the ductility, compressive and tensile strength. In this way ice becomes a reliable material for construction at temperatures of -8C or lower. The extrusion of cellulose-reinforced ice leads to the drainage of water just before the extrusion nozzle. Therefore, the compressed water-cellulose mixture will form clots in the nozzle, leading to an unreliable process. By mixing fibers, water and a jelly of Guar Gum and Xanthan Gum this problem was solved. A hybrid mixture with other materials such as sand will increase the material properties of the ice composite further more. It will increase both its bending as its compression strength. Adding cellulose showed promising post-peak strain softening behavior. Experiments with different temperatures and testing speeds were conducted. From these experiments it was concluded that both the ultimate strength and the stiffness of the specimens decrease with increasing temperature. At tempters close to 0ºC, the post-peak behavior also changes from brittle to more ductile. Furthermore, the bending tests were modelled in a FEM program and compared with the executed experiments. Based on these experiments in December 2018 the first 3D-printed grid shell in ice composite was realized in Harbin, China.