The most important part of the brickwork of ovens is the refractory brickwork, which is the inner layer of wear and resistance to the action of high temperature, and to various physical and chemical agents. The refractory materials (materiaux refractaire) which make up the refractory brickwork are those materials which withstand high temperatures without significant changes of their properties. These materials must also resist to the mechanical and chemical actions faced during furnace operation. For these reasons, due to the diversity of types of ovens and due to the diversity of types of products developed in these ovens, fuels, slag, temperature, mechanical and chemical actions, etc., the refractory products are very different. Generally, refractory products are artificial products which are used in various forms and aspects: refractory bricks, refractory powders (ciment refractaire, chamotte powder, silica, etc.), refractory concretes, refractory plastic, refractory coatings, etc.

 

Refractory cement totally differs in composition from ordinary cement which we all know. This type of cement contains mostly aluminium silicate, which gives its resistant, refractory properties. The concrete manufactured based on this type of cement, depending on the grain size and the type of aggregate used as well as on the proportion of refractory cement used, has a certain index of refractoriness (lasting up to certain temperatures). The mechanical strength of refractory cement (ciment refractaire) is certainly much smaller than with ordinary cement. Refractory concrete can be used for casting certain forms that can be used in the construction of furnaces (the tiled stove is also a type of oven), but not with steel reinforced concrete. You must consider that the temperature in the furnace of the stove, when heating with wood, does not exceed 350-500 degrees C.

 

The use of refractory concrete has some advantages such as: the ease of supply, the speed and ease of commissioning, the low cost and convenient operation. However, the physical -mechanical properties of refractory concretes are lower than those of shaped products of similar composition. Thus appears the necessity to realize products that share similar characteristics to burned products but which keep the benefits of refractory concretes. This can be achieved by lowering the content of cement from refractory concrete, even to its removal.

 

The relatively high content of calcium oxide, which is brought by the aluminous cement, determines in refractory concretes with normal content of cement (~ 20%) a reduction of physical and mechanical properties at high temperatures, to this reduction contributing the high water / cement ratio too.

 

Refractory concrete with low dosage and ultra low dosage of cement presents important advantages over conventional refractory concrete. Among these benefits there are: the reduction of the proportion of water, reducing the porosity of the strengthened structure, reducing the loss of mechanical strength in the critical temperature, as well as improving of the refractoriness level.

 

The industry of refractory materials (materiaux refractaire) is very well represented in the online environment, so all potential customers needing ciment refractaire can find it on specialized websites of the producers.