Everyone is familiar with cement, and it is indispensable in construction, so it may be common cement that everyone sees a lot, so how much do you know about aluminate cement?
1. The aluminate cement sets and hardens quickly. The 1d strength can reach more than 80% of the maximum strength, and is mainly used for projects with urgent construction periods, such as national defense, roads and special emergency repair projects.
2. The aluminate cement has a large heat of hydration and concentrated heat release. The heat of hydration released in one day is 70% to 80% of the total, which makes the internal temperature of the concrete rise relatively high. Even if it is constructed at -10 °C, the aluminate cement can quickly set and harden, which can be used for winter construction projects.
3. Under ordinary hardening conditions, the aluminate cement has a strong anti-sulfate corrosion effect because the cement stone does not contain tricalcium aluminate and calcium hydroxide, and has a high density.
4. The aluminate cement has high heat resistance. For example, the use of refractory coarse and fine aggregates (such as chromite, etc.) can be made into heat-resistant concrete with a service temperature of 1300 ° C to 1400 ° C.
5. However, the long-term strength and other properties of the aluminate cement tend to decrease, and the long-term strength decreases by about 40%-50%. Therefore, the aluminate cement is not suitable for long-term load-bearing structures and projects in high temperature and high humidity environments. The aluminate cement is only suitable for emergency military projects (road construction, bridges), emergency repair projects (plugging, etc.), temporary projects, and the preparation of heat-resistant concrete.
6. The mixing of the aluminate cement with Portland cement or lime will not only cause flash setting, but also cause cracking or even destruction of concrete due to the formation of highly alkaline hydrated calcium aluminate. Therefore, in addition to not being mixed with lime or Portland cement, it should not be used in contact with unhardened Portland cement.
The aluminate cement has the characteristics of early strength and high strength, and its 3-day strength is equivalent to the 28-day strength of Portland cement of the same label, which is suitable for emergency repair and construction projects. The application of prefabricated components can save the energy cost of steam curing; the aluminate cement has good frost resistance and is widely used in low-temperature construction projects in winter; the aluminate cement is much better than Portland cement in impermeability and seawater corrosion resistance , suitable for marine construction projects; the aluminate cement has special effects on the consolidation of hazardous wastes, and is suitable for the curing of hazardous and toxic wastes.
