Explanation

refractory concrete (also known as refractory castable) is a special concrete composed of appropriate cementitious materials, refractory coarse and fine aggregates and water in a certain proportion, which can work in the temperature range of 900 ° C to 1600 ° C, and maintain its physical and mechanical properties, including refractoriness, thermal stability, load softening point and shrinkage under high temperature. Its composition and ingredient ratio are similar to those of refractory castables. The construction performance, physical and chemical properties, and usage effect are also similar to those of refractory castables. The coarse and fine refractory aggregates of refractory concrete can be selected from crushed refractory bricks, andesite, basalt, bauxite clinker, sintered magnesite and chromite according to the service temperature. According to the cementitious materials used, it can be divided into silicate refractory concrete, aluminate refractory concrete, sulfate refractory concrete, phosphate refractory concrete, bauxite refractory concrete, chloride refractory concrete, etc. Generally, Portland cement is used below 900 ° C, bauxite cement is used between 1200 ° C and 1630 ° C, and aluminate cement can be used above 300 ° C and 1400 ° C. If the temperature requirement is higher, aluminum phosphate cementitious materials can be used. This kind of concrete is widely used in the construction and lining of industrial kilns, as well as in thermal equipment, chimneys, metallurgy, petroleum, nuclear power and other fields. It should be noted that the conditions used below 900 ° C are usually referred to as heat-resistant concrete.

Classification