Apr 12 2002
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Calcium aluminate cements (CACs) are chiefly utilized as binder in monolithic refractories. Further applications of CACs are industrial flooring products (like cast house floors), concretes and mortars resistant to chemicals, sewer applications, expansive grouts, tile adhesives, protective coatings, floor screeds, and building chemistry products (CAC is mixed with OPC to ensure desirable setting times).
Monolithic Refractory Binder
CACs are mainly used as binders in monolithic refractories, specifically refractory castables. Cement with higher alumina content is often used, which has the ability to combine precision-graded aggregates together in the green state. When these materials heat up consequently, cement sinters with the aggregate, thereby creating a refractory matrix.
Different types of refractory aggregates—such as bauxite, chamotte, silicon carbide, and tabular alumina—are used in castables. These elements are chosen based on the properties necessitated by an application. Moreover, the products are used in non-ferrous metallurgical industries, iron and steel sectors, and also in pre-heaters of incinerators and cement kilns.
The CAC is selected based on its alumina content for any application. The cement can be used in higher-temperature applications (pyrometric cone equivalent), if the alumina content is more.
Building Chemistry Products
Floor leveling compounds, sealers, rapid floor screeds, tile adhesives, bedding mortars, tile grouts, and repair mortars are different types of building chemistry products. The mineral base of this wide range of products is a mixture of CAC and Portland cement. Additionally, the blend may include slag, admixtures, gypsum, polymers, lime, and fine calcareous material.
Currently, liquid waste has become highly concentrated; hence, highly resistant construction materials are required. Calcium aluminate types of cement do not include any free lime, which is vulnerable to the impact of sulfates. Moreover, CACs provide improved resistance to abrasion and biogenic corrosion.
The porosity matrix of concretes prepared by mixing calcium aluminate cement is lower. They also exhibit higher resistance to both abrasion and sulfate attack. Consequently, calcium aluminate cement is desirable for making chemical-resistant concretes, which are mainly used in products such as industrial floorings, for example, cast house floors.
Factory-made refractory concretes are assembled in a metal enclosure. Subsequently, it is completed by using conventional wood, facades, and masonry materials, making it into a traditional masonry fireplace. Refractory concrete such as these are prepared from lightweight aggregate and high alumina cement.