Friday, July 22, 2011

Cementing materials

Appointment of binding materalov - tie into a monolithic whole all the components of the future product or design. There are two types of binders - hardening only in the air - the air and materials on the properties of which after the beginning of setting water can not be adversely affected, and in some cases has even a positive impact - gidavlicheskie. To air is clay, plaster and common lime. By hydraulically - hydraulic lime and cement. Clay Clay - a soft, fine variety of rocks. For dilution with water forms a plastic mass, readily undergo any morphogenesis. When firing the clay sinters, hardens and turns into a kamnevidoe body, and at higher temperatures, roasting is melted and can reach the vitreous state. Depending on the impurities clay takes a different color stains. The most valuable commodity form of clay - white clay - kaolin. Clay has the ability to absorb water up to a certain limit, after which she was not in a position to absorb or pass through itself. This property of clay used to create the bulk of waterproofing layers. Depending on the resistance of clay to produce a temperature lekgoplavkie clay, refractory and refractory. Their melting temperatures, respectively: 1380 to 1550 and above 1550 degrees. Pure kaolin melts at temperatures above 1,750 degrees. Refractory clay used as raw materials for the manufacture of refractory materials. Lime is produced by calcining limestone at high temperatures. Thus obtained lime is called lime-kipelka for being in contact with water is an active carbon footprint. This process is called "quenching." For most applications of lime, it must be "repaid." Quenched lime into a dough that can be stored for many years. From long term storage properties of lime may even improve. To obtain the binding solution of lime putty mixed with sand. This solution was used when laying foundations for the furnace, chimneys up to 4-5 meters and is used for plastering the walls of houses and stoves. Cement Cement - the most common binder allows you to receive products and designs are the highest durability. Cement - the result of finely grinding the sintering products of one type of clay - marl or mixture of limestone and clay. The sintering process is conducted in special furnaces. Under refinement of the sintering products are made-dose supplements of gypsum, slag, sand and other components which allows to obtain cement with a variety of properties. Depending on the source of raw materials and additives introduced cements are divided into Portland cement and slag cement. Among potrlandtsementov isolated, quick and Portland cement with mineral additives. Concrete structures, which use one or another brand of cement may acquire unique properties. Above all, this extra strong concrete, for example, runway airfields and missile launch sites, frost, heat and salt tolerant brand. To indicate the maximum strength properties of cement applied the concept of brand. Mark 400 indicates that the plant's laboratory at trial testing hardened cement cube with an edge of 100 mm, while crushing on the press he sustained load of not less than 400 kg/cm2. Are the most common brands from 350 to 500. Made the same brand of cement to 600 th and even the 700 mark. All cements are fast enough time hardening. Start hardening - setting - is within 40-50 minutes, and the end of curing is about 10-12 hours. Gypsum Gypsum is produced by burning rocks - gypsum and the subsequent shredding of the product of burning. Gypsum significantly inferior cement on the strength of products produced by its use as a binder, as well as inferior to him in the water absorption - the ability to resist moisture penetration into the body design. Therefore, gypsum is used in designs and solutions that work indoors. Gypsum is grade A fast setting (the end of setting at least 15 minutes) and grade B - normal hardening (final set - 30 minutes). Gypsum is the basis of solutions to seal small cracks and uneven concrete planes walls and ceilings, as well as plastering furnaces.

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