Hardening of hydrothermal hot pressed calcium silicate compacts with rice husk as fiber reinforcement

Abstract

Hydrothermal hot-pressing (HHP) technique was used to solidify calcium silicate hydrate powders at a relatively low temperature as 200°C and low pressure (20 MP a) with short reaction time (30 min). Diatomaceous earth, α-quartz, fly ash and silicic acid were used as the Si sources. Waste rice husk was used for fiber reinforcement to strength the hydrothermal hot pressed calcium silicate compacts. The tensile strength of the solidified bodies with and without rice husk was tested. The solidified bodies with reinforced by 5% rice husk exhibit high tensile strength (∼9 MPa), which is almost three times lager than their non-additives compacts. There is no effect of additives for the density of solidified bodies, which remains almost constant at ∼2gcm⁻³similar to their non-additive compacts. The developed low temperature solidification method is expected to be useful in the development of an environmentally friendly processing route for making artificial wood.

Key words:

• Calcium silicates
• Hydrothermal hot pressing
• Rice husk
• Tensile strength