Detailed Introduction to Refractory Concrete

Refractory concrete is a refractory material that is composed of refractory aggregate, refractory powder, and cementing agents or additional additives in a certain proportion. It can be used directly after stirring (the cement cementing agent should be mixed with appropriate water), shaping, and curing.

Refractory aggregate is the skeleton of refractory concrete and plays an important role in the high-temperature physical and mechanical properties of refractory concrete. It has many varieties, and any raw material that can be used to make refractory bricks can be used as refractory aggregate. In addition, some industrial slag, waste refractory bricks, and natural raw materials, such as pyrophyllite, white sandstone, and zircon stone, can also be used as refractory aggregates; light aggregates mainly include ceramsite, expanded perlite, expanded vermiculite, oxidized Aluminum hollow balls, and porous clinker, etc. Refractory aggregates come in different thicknesses, and the maximum particle size is also limited. Generally speaking, the variety, particle size, and particle gradation of refractory aggregates should be selected based on the thickness of the kiln and thermal equipment, construction methods, operating temperatures, and requirements for high-temperature physical and mechanical properties.

Refractory powder can improve some properties of cement binders, reduce the amount of cement, increase the workability of refractory concrete mixtures and the density of concrete, and improve fire resistance. At the same time, refractory powder can react with certain inorganic binders to cement and adhere to refractory aggregates, giving refractory concrete strength and high-temperature physical and mechanical properties.

The main function of the cementing agent is to gel and combine refractory aggregates and powders to form refractory concrete with certain properties.

There are many types of admixtures, such as coagulants, water-reducing agents, mineralizers, and expansion agents. Generally, the dosage is small, and its main function is to improve and enhance the performance of refractory concrete to better meet the requirements of construction and use.

At present, the names of refractory concrete and its constituent materials in my country are not uniform. For example, refractory concrete is also called heat-resistant concrete, refractory aggregate is also called aggregate, refractory powder is also called admixture, admixture, and cementing agent is also called Adhesive materials, cementitious materials, bonding agents, etc. For the convenience of description, this new type of refractory material is called refractory concrete in this book. The terms of its constituent materials include refractory aggregate, refractory powder, and cement, as well as admixtures, etc.