Calcium silicate board is a type of insulating material made from calcium silicates and cellulose fibers. It has good strength, fire resistance, and acoustic insulation properties. Typical properties of a high strength 50 mm calcium silicate board would be:
Density: 400-500 kg/m3
Compressive strength: 450-1200 kPa
Flexural strength: 1.5-2.0 MPa
Thermal conductivity: 0.05-0.08 W/mK (at 10°C mean temp.)
Maximum service temperature: 650-800°C
Water absorption: <5%
Fire resistance: Non-combustible, A1 Euroclass fire rating
The high strength is achieved through:
Higher density
Higher density boards have more calcium silicate and less cellulose fibers, resulting in higher strength.
Smaller pore size
Smaller pores are formed during manufacturing which improves the compressive and flexural strength.
Higher percentage of calcium silicate
More of the stronger calcium silicate component increases the strength of the board.
Other properties like low thermal conductivity, fire resistance and acoustic insulation usually remain similar to regular (lower strength) calcium silicate boards. The main advantages of the high strength boards are:
Suitable for load bearing applications
Easier to handle and install
Withstand impact and vibration better
Thinner sections can be used for the same application