Composition of refractory cement

What was mentioned upstairs should be called fire-resistant concrete, I think. Reinforced concrete made with cement as a binder: its composition, material ratios, and areas of application: 1. Bauxite cement reinforced concrete (1) Binder: Bauxite cement of grade 42.5 or higher, with a proportion of 15% to 20%. (2) Aggregates: Made from grade 2 and grade 3 bauxite clinker, or grade 1 and grade 2 clay clinker, as well as waste high-alumina bricks and waste refractory clay bricks. The particle size of fine aggregates is less than 5 mm ； The mix ratio is 30% to 40%. The particle size of the coarse aggregate is 5–15 mm ； The mix ratio is 30% to 40%. (3) Powder material (mixing agent): Similar to aggregates; no less than 70% of the particles have a particle size of less than 0.088 mm ； The mix ratio is 0~15%. The characteristics and application scope of bauxite cement refractory concrete are: high strength at normal temperatures, wide availability of raw materials, and easy construction. It is suitable for the refractory layers in various parts of boilers. 2. Silicate cement refractory concrete: (1) Binder: Silicate cement of grade 42.5 or higher, with a proportion of 15% to 20%. (2) Aggregates: Made from first-class or second-class clay clinker or waste refractory bricks. The particle size of fine aggregates is less than 5 mm ； The mix ratio is 35% to 40%. Coarse aggregate particle size: 5–15 mm ； The mix ratio is 30% to 40%. (3) Powder material: Same as aggregate. Not less than 70% have a particle size of less than 0.088 mm ； Its mixing ratio is ≤15%. The characteristics and application areas of silicate cement refractory concrete are: low cost and easy construction. It is suitable for the refractory layers in various parts of boilers. 3. Slag cement refractory concrete: (1) Binder: Slag cement of grade 42.5 or higher, with a proportion of 16% to 20%. (2) Aggregates: grade II or grade III clay clinker or waste refractory bricks. The particle size of fine aggregates is less than 5 mm ； The mix ratio is 35% to 40%. The particle size of the coarse aggregate is 5–15 mm ； The mix ratio is 40% to 45%. (3) Powder material: The characteristics and application scope of this type of refractory concrete are its low cost, wide availability of materials, and ease of construction. It is suitable for the refractory layer in the low-temperature areas of boilers. 4. Low-calcium aluminate cement refractory concrete: (1) Binder: Low-calcium aluminate cement of grade 42.5 or higher, with a proportion of 12% to 20%. (2) Aggregates: made from grade II or grade III bauxite clinker or waste high-alumina bricks. Fine aggregate, with a particle size of less than 5 mm ； The mix ratio is 30% to 40%. Coarse aggregate: particle size of 5–15 mm ； The mix ratio is 30% to 40%. (3) Powder material: Similar to the aggregate, not less than 70% of its particles have a particle size of less than 0.088 mm, and its proportion is 0–15%. This type of refractory concrete has a higher refractoriness than bauxite-cement refractory concrete; in addition to being suitable for use as refractory layers in various parts of boilers, it can also be used for burner nozzles. 5. Hot-water resistant cement refractory concrete: (1) Binder: Hot-water resistant cement of grade 52.5 or higher, with a proportion of 25% to 30%. (2) Aggregates: Made from first-class or second-class clay clinker or waste refractory clay bricks. Fine aggregate, with each particle being smaller than 5mm ； The mix ratio is 35% to 40%. Coarse aggregate, with each particle ranging from 5 to 15 mm in size ； The mix ratio is 30% to 40%. (3) Powder: It can be omitted. This type of refractory concrete is easy to construct. It is suitable for the refractory layers in various parts of boilers. The water-cement ratio for the above five types of refractory concrete should be 0.35 to 0.45.

What was said upstairs is very professional, but there’s one thing I still need to point out: the formulations of linings vary from manufacturer to manufacturer, so the proportions of fire-resistant cement also differ. To be absolutely sure, you should consult the manufacturer regarding the lining you plan to use! The insulation lining is usually 4 parts lining to 1 part cement.

Add 5% ceramic fiber cotton to each mixture to enhance the crack resistance of the concrete.

Refractory lining: refractory cement and sand; here it can’t be called sand – it should be referred to as solid material, with different particle sizes. The method of filling it in is described on the 2nd floor

The requirements for the physical and chemical properties of refractory concrete (unshaped castables), such as compressive strength and flexural strength, as well as its high-temperature performance characteristics like linear expansion rate and refractoriness, are achieved through an appropriate combination of aggregates, powders, and a binder (aluminate cement); the specific proportions should be determined through tests conducted by the material manufacturers. The \"Handbook of Refractory Materials for Industrial Furnaces\" can be referred to.

It is necessary to handle each case individually based on the conditions of the area where it will be used!

Reply to 7# wangxuegui: Hello, you work in the field of refractory materials. I have a question I’d like to ask you. Among building materials, what are the first-class and second-class fire-resistant materials as specified in general building codes? What classification does a typical steel structure fall under? How thick a layer of fire-resistant coating is needed on a steel structure to meet first-class fire resistance requirements? Thank you. My Q342731973; looking forward to learning from your guidance.