Preparation and characterization of high compressive strength foams from sheet glass

High compressive strength glass foams were produced using sheet glass cullet with the aid of 1 wt.% SiC powder, as gassing agent, and the incorporation of small amounts of an alkali earth aluminosilicate glass powder (AD), which is intrinsically prone to be crystallised to anorthite and diopside. The amount of SiC used as well as the mean particle sizes of the powders of both glasses and SiC were lower than those used in earlier studies. The experimental results showed that homogenous microstructures of large pores could be obtained by adding 1 wt.% SiC. The compressive strength of the glass foams was considerably increased when the incorporated AD-glass was higher than 1 wt.%. It is concluded that the presence of the AD glass is beneficial for the produced glass foams because of the formation of a well packed honeycomb structure which features an optimal distribution of pentagonal- and hexagonal-like shaped pores surrounded by dense struts. The crystallization of wollastonite and diopside inside the struts should also have a positive impact on the mechanical behaviour of the produced porous glass foams.