Aluminate cement is a water-hardened cementitious material manufactured from bauxite and limestone, calcined to generate a clinker with calcium aluminate as the major component and an alumina concentration of around 50%, and then crushed. Aluminate cements are often yellow or brown, however they can also be grey. The major minerals in aluminate cements are calcium aluminate and other aluminates, plus a tiny quantity of dicalcium silicate (2CaO-SiO2) (2CaO-SiO2). Grey and white are the predominant colors.
1. In order to keep the setting time of aluminate cement under control, it should not be mixed with silicate cement, lime, or other cementitious substances that can precipitate calcium hydroxide, and the mixing equipment should be cleaned before use.
2. Except for refractory concrete, aluminate cement should be used in the same proportions as conventional cement. Waterproof materials should be used to isolate the concrete from the earth when it is in direct contact with it (e.g. plastic sheeting and linoleum).
3. Aluminate cement should be left alone for 3-6 hours after forming, and no water should be added; otherwise, water will cause the aluminium glue to precipitate out continuously, preventing it from hardening; and, at the same time, early water loss will cause carbonation, making the concrete surface loose and chalky, and cracks inside, compromising the concrete's strength. So three to six hours after forming must be supplied water in time to moist maintenance, the temperature is 15-25 °C, when more than 25 °C should be used to reduce the temperature measures, the maintenance period is not less than three days, and steam maintenance is generally not employed.
4. Control the amount of concrete to be mixed each time so that it is consumed within 20 minutes. The mixing water should be drinkable and have a pH of 70.5, and it should be mixed continuously throughout the interval. If the hardened concrete is given water again for use, the concrete may fail to solidify.
5. Aluminate cement must not contain any admixtures that have not been tested.
6. When concrete is used within a container, proper ventilation is required, and direct sunlight should be avoided when the container is used outdoors; otherwise, the concrete's strength will be greatly diminished, if not completely absent.
7. Aluminate cement should not be used in contact with silicate cement concrete that has not yet hardened, but it can be used in contact with silicate cement concrete that has delaminated strength. However, the joint should not be wet for an extended period of time, as the concrete will swell and the structure will lose strength.
8. Aluminate cement should not be poured into big volume concrete, and the thickness should not exceed 0.3 m. If the thickness exceeds this limit, the concrete must be provided water soon after hardening, and cooling and cooling measures must be taken. Reinforcing steel should be coated with a combustible layer reserved for expansion joints when used in reinforced concrete, and the protective layer of reinforced concrete should not be less than 60mm thick.
9. When selecting refractory aggregates and powders, ensure that the clinker meets the batching design criteria.
