Composite foamed alkali-activated concrete with slag and steel slag Available to Purchase

Thermally expandable foaming microspheres (FMS) are used as a foaming agent in many different fields due to their excellent dimensional stability and elastic properties. In this study, lightweight thermal insulation materials were prepared by adding FMS to foamed concrete containing alkali-activated steel slag and blast-furnace slag. The dry bulk density, cube strength, thermal conductivity and drying shrinkage of samples with different compositions were investigated and their microstructure was analysed using scanning electron microscopy and X-ray diffraction. With the addition of FMS, foamed materials with a dry bulk density of 625 kg/m³ and 40 mm cube strength of 3·6 MPa could be obtained. The 28 d drying shrinkage was 0·8 mm/m and the thermal conductivity was 0·102 W/m.K (thermal inertia index of 4·66). The results showed that FMS can be used as an organic foaming agent to prepare lightweight thermal insulation materials with improved insulation performance and mechanical properties.