commonly known as High Alumina Cement， is a hydraulic binder produced by sintering a mixture of bauxite (aluminum ore) and limestone. Its primary mineral phase is monocalcium aluminate (CA), characterized by:  

1. Rapid Hardening: Achieves >80% of ultimate strength within 24 hours.  

2. High-Temperature Resistance：Refractoriness up to 1,300°C, ideal for refractory concretes.  

3. Chemical Durability: Superior resistance to sulfate and acid attack.  

4. Low-Temperature Performance: Hydrates effectively even at sub-zero temperatures.  

5.Strength Regression: Long-term strength may decrease in warm/humid conditions (avoid steam curing).  

Key Applications:  

- Emergency repairs (e.g., roads, bridges)  

- Cold-weather construction  

- Refractory linings (furnaces, kilns)  

- Marine/chemical corrosion-resistant structures