Preparation and Characterization of Calcium Silicate/Vermiculite Composite

A new calcium silicate/vermiculite composite for building material has been prepared from unfired vermiculite, calcium hydroxide, silica and pulp by autoclaving at 187°C at a pressure of 1.08 MPa. The product exhibited the vermiculite crystals dispersed uniformly in a definite direction among the matrix of calcium silicate. The composite showed marked plastic deformation caused by interlayer sliding of vermiculite. The building material was fixed by nails and screws and also possible to cut and saw like artificial wood. The board had superior humidity control originated from chemical adsorption of water molecules at the interlayer of vermiculite, and relative humidity in an experimental house was maintained to be 50%. Formaldehyde was chemically adsorbed to the composite, and there was no release of formaldehyde at elevated temperature.