Properties of lightweight high calcium fly ash geopolymer concretes containing recycled packaging foam

In this research, the properties of lightweight geopolymer concretes containing recycled packaging foam were studied. The recycled foam was crushed to sizes of 2.35-4.75 mm and used as lightweight aggregate. Compressive strengths and densities with liquid alkaline/ash ratios of 0.5-1.0, sodium silicate/NaOH ratios of 0.33-3.0, NaOH concentrations of 5-15 molars, curing temperatures at 25 and 60 °C, and foam contents of 0.85-1.05 %wt. were tested. In addition, the thermal conductivities of geopolymer blocks were determined. Results showed that the lightweight geopolymer blocks of densities of 1000-1300 kg/m3, with satisfactory strength and low thermal conductivity can be made. This gave a twofold advantageous viz. the use of low carbon footprint fly ash geopolymer and the reuse of packaging foam.