Structure characterization and optimization of process parameters on compressive properties of glass-based foam composites

The influence of process parameters, including temperature, reaction time, and amount of foaming agent (SiC), on compressive property and porosity of glass‐based foam composites was studied by Box‐Behnken experimental design. The interaction between the process parameters and their statistical significance on porosity and compressive strength was assessed through ANOVA. The glass‐based foams, prepared from silicate wastes, were characterized by XRD, SEM, DSC, and compressive tests. Processing temperature was considered as the most significant factor. The two crystalline phases resulting from the heat treatment at 900–1000˚C have been identified as Ca2Mg0.75Al0.25Si1.75O7 and CaSiO3. Two quadratic equations, correlating the compressive strength and porosity with the three process parameters, were developed whose R2 values are 0.9977 and 0.935, respectively. The optimal process parameter settings to achieve an adequate porosity (56.6%) and high compressive strength (11.7 MPa) were determined. The glass‐based products exhibited typical behavior of brittle foams. The stress‐displacement curve implies that the failure mode is mainly due to damage accumulation process. Box‐Behnken experimental design offers a cost effective option in the mass production of a wide range of glass‐based foam products with promising engineering applications. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 800–807, 2014