Global warming has reached an alarming level in recent decades in the world. Thermal insulating building materials can actually help in substantial reduction in energy consumption by preventing heat from entering the indoor environment so that less energy would be consumed. Alternatively, consumption of energy for heating in cold regions can be reduced. Thermal insulating building materials can help in peak clipping and peak shifting of energy consumption....[ Read more ]

Global warming has reached an alarming level in recent decades in the world. Thermal insulating building materials can actually help in substantial reduction in energy consumption by preventing heat from entering the indoor environment so that less energy would be consumed. Alternatively, consumption of energy for heating in cold regions can be reduced. Thermal insulating building materials can help in peak clipping and peak shifting of energy consumption.

In this research, thermal insulating cement-based products were developed by extrusion technique. Extrusion is a common technique in facilitating mass production. It can also enhance the mechanical properties of extruded products. Indeed, improvement of strength and toughness of the cement-based products by extrusion is a perfect solution to the decrease in mechanical properties for products with large incorporation of thermal insulating materials such as foam plastic and paraffin.

Twelve formulae of mixes of small scale wall panels were designed and manufactured by extrusion to test the steady state thermal conductivity and heat capacity of the wall panels at the Controlled Environment Test Facility at HKUST. The formulae were partially referenced with the successful records in the research group, but there was a breakthrough that the incorporation of paraffin was 10% by volume. Light expanded clay aggregate (LECA) was also applied to investigate its effect in thermal and mechanical properties. Test results revealed that foam plastic was very effective in improving the thermal insulating property of the wall panels. Besides, paraffin and LECA also showed their ability in the same aspect. From the mechanical tests, extrusion products were found to be very strong as expected. For panels incorporated with large amount of foam plastic and paraffin, their insulating effectiveness were also satisfactory.