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Lime, cement and concrete
Published in Arthur Lyons, Materials for Architects and Builders, 2019
Calcium aluminate cement should not be used for foundations or structural purposes, but only for specific heat-resisting applications and where deterioration rates can be predicted. However, it is useful where rapid strength gain is required, allowing the fast removal of formwork within 6 to 24 hours. The fast evolution of heat allows concreting to take place in low temperatures. The material also has good heat-resistant properties, so it may be used to produce refractory concrete. Good-quality calcium aluminate cement is generally resistant to chemical attack by dilute acids, chlorides and oils, but not alkalis. When mixed with Portland cement, it produces a rapid-setting concrete, suitable for non-structural repairs and sealing leaks.
Material properties
Published in Charles E. Reynolds, James C. Steedman, Anthony J. Threlfall, Reynolds's Reinforced Concrete Designer's Handbook, 2007
Charles E. Reynolds, James C. Steedman, Anthony J. Threlfall
As well as cement for general use (which used to be known as ordinary Portland cement), cements for rapid hardening, for protection against attack by freezing and thawing, or by chemicals, and white cement for architectural finishes are also made. The cements contain the same active compounds, but in different proportions. By incorporating other materials during manufacture, an even wider range of cements is made, including air-entraining cement and combinations of Portland cement with mineral additions. Materials, other than those in Portland cements, are used in cements for special purposes: for example, calcium aluminate cement is used for refractory concrete.
Inorganic Polymers
Published in Charles E. Carraher, Carraher's Polymer Chemistry, 2017
The cements cited above are all typically derived from Portland cement. The following are non-Portland cements: Calcium-aluminate cement has a much higher percentage of alumina than does Portland cement. Furthermore, the active ingredients are lime, CaO, and alumina. In Europe, it is called melted or fused cement. In the United State, it is manufactured under the trade name Lumnite. Its major advantage is its rapidity of hardening, developing high strength within a day or two.Magnesia cement is largely composed of magnesium oxide (MgO). In practice, magnesium oxide is mixed with fillers and rocks and an aqueous solution of magnesium chloride. This cement sets up (hardens) within 2–8 h and is employed for flooring in special circumstances.Gypsum, or hydrated calcium sulfate (CaSO4 ⋅ 2H2O), serves as the basis of a number of products, including plaster of Paris (also known as molding plaster, wall plaster, and finishing plaster). The ease with which plaster of Paris and other gypsum cements can be mixed and cast (applied) and the rapidity with which they harden contribute to their importance in the construction field as a major component for plaster wall boards. Plaster of Paris' lack of shrinkage in hardening accounts for its use in casts. Plaster of Paris is also employed as dental plaster and pottery plaster, and as molds for decorative figures. Unlike Portland cement, plaster of Paris requires only about 20% water and dries to the touch in 30–60 min giving maximum strength after 2–3 days. Portland cement requires several weeks to reach maximum strength.
A State-Of-The-Art Review on Materials Production and Processing Using Solar Energy
Published in Mineral Processing and Extractive Metallurgy Review, 2023
It is not possible to conclude this section without referring to the calcium aluminate synthesis. Abdurakhmanov, Paizullakhanov, and Akhadov (2012) were the first in investigating with these compounds using solar energy. They did so with the aim of using calcium aluminates with impurities of neodymium and strontium based on the luminescence of these materials to obtain light-generating material. However, it was not until the research of Fernández-González et al. (2018d) when the synthesis of calcium aluminate cements using concentrated solar energy was proposed. Calcium aluminate cements are the most important type of cements after the Portland cement that are characterized by the rapid hardening, resistance to high temperatures, to temperature changes, to chemical attack and to impact and abrasion. Nevertheless, this type of cement, as opposed to Portland cement, is expensive due to the control of the impurities and the high temperature required for its synthesis. Fernández-González et al. (2018d) did preliminary research in the Odeillo solar furnace oriented to the synthesis of the high alumina calcium aluminate cement and observed that the habitual phases of calcium aluminate cements were obtained at the end of the process with certain heterogeneity due to the experimental conditions (static tests). Anyway, these researchers demonstrated that concentrated solar energy is a suitable candidate to obtain this kind of cements, although further research is needed for the implementation of this process at larger scale.