Mechanical properties of foamed concrete exposed to high temperatures

This paper reports the results of an experimental and analytical study to investigate the mechanical properties of unstressed foamed concrete exposed to high temperatures. Two densities of foamed concrete, 650 and 1000 kg/m3, were made and tested with additional tests being performed on densities of 800, 1200 and 1400 kg/m3 for additional data. The experimental results consistently demonstrated that the loss in stiffness for foamed concrete at elevated temperatures occurs predominantly after about 90 °C, regardless of density as water expands and evaporates from the porous body. From a comparison of the experimental results of this research with a number of predictive models for normal strength concrete, this research has found that the mechanical properties of foamed concrete can be predicted using the mechanical property models for normal weight concrete given that the mechanical properties of foamed concrete come from Portland Cement CEM1.

► Loss in stiffness for foamed concrete at elevated temperatures occurs after about 90 °C.
► Primary mechanism causing stiffness degradation is microcracking.
► Reducing the density of foamed concrete reduces its strength and stiffness.
► The porosity of foamed concrete is principally a function of density.
► Mechanical properties of foamed concrete can be predicted using the models for normal concrete.