Blast furnaces in modern metallurgy can weigh more than 30 thousand tons. The foundation of the blast furnace is the very foundation of the installation. It consists of an outer part - a stump and a sole, located below the level of the factory floor surface. The blast-furnace foundation is also used as a support for structures in contact with the furnace (foundry yard, subdomain).
Concrete is the main raw material for the foundation of the kiln. Its lower part is a solid slab of ordinary concrete, and the upper part is made of refractory concrete, where Portland cement of grade 400 and cement of at least 300 grade are present in the mortar. The foundation is able to withstand incredible loads, as it is a reinforced concrete block.
The foundation is laid out on solid continental soil. It is desirable that the base be in contact with a rock of sedimentary or igneous origin. But during construction on weak soil, a support is made from piles. Loess-like soils pose a great danger, which, with high humidity, give a large sediment, fraught with a violation of the integrity of the foundation as a whole and the evenness of the course. Consequences can be blast furnace profile distortions, cracks, axial hearth breakthrough.
The foundation is rescued from thermal destruction by the modern method of cooling the lower part of the bottom layer with the help of water or air, maintaining the temperature regime within 100-150 ° C. So that the foundation slab is not hollow, raw materials that do not contain the slightest debris are used for concreting it. The concreting process itself takes place in an accelerated rhythm, non-stop to obtain a homogeneous mass.
The condition of the blast-furnace base is carefully monitored using thermocouples (instrumentation), major repairs are being carried out.
