Key points for construction of lightweight insulation castable

Several points should be noted when constructing lightweight insulation castable:
1.Mould : The mould for the construction of lightweight insulation castable can be made of steel or hardwood (plywood). The mould must have sufficient strength, good rigidity, no deformation, no displacement, no cracks, and steel mould need to be coated with mold remover. The wooden mould should be coated with a water repellent. The reusable mould should be cleaned and painted before using. The inspection and cleaning holes shall be made of neat plywood mold. There should be more than 4 metal tension bars per square meter for fixing wooden mould. And the tension bars of mould should be cold-welded on anchors.
2.Water castable ratio: When stirring lightweight insulation castable, the amount of added water must be strictly controlled according to the instructions, and must not exceed the limit. Under the premise of ensuring the construction performance, the amount of water added should be less and not more.
3. Stirring: The stirring time of lightweight insulation castable, should be no less than 5 minutes (subject to the requirements of the instructions), and a mixer should be used during operation. When mixing, it is better to dry mix first, then add 80% of water to stir, and then, depending on its dryness and wetness, slowly add the remaining water and continue to stir until it is suitable for construction operations. Clean the mixer before stirring the lightweight insulation castable.
The binders, refractory powders and lightweight aggregates for lightweight insulation castable have different varieties and dosages. And the performances of lightweight insulation castable varies. Castables with water-reducing additives have significantly reduced water consumption and increased strength. Adding additives with low density can reduce the bulk density of the castable and increase its heat insulation performance, but its strength is reduced significantly and the more the additive is used, the more its strength is reduced. Therefore, the lightweight insulation castable should be properly formulated and selected according to the use of the thermal kiln and the use of the castable, to achieve the longevity and energy saving of the kiln.