High aluminum cement (HAC), also known as calcium aluminate cement (CAC) or calcium aluminate cement, is a special type of cement composed of calcium aluminate.
It is made from raw materials such as limestone or chalk and bauxite, a special clay with high alumina content. HAC has several advantages. It has high compressive strength and strong reactivity. Its initial settling time is about 3.5-4 hours and the final settling time is about 5 hours, which is more processable than ordinary silicate cement. It is very resistant to chemical erosion, generates more heat during solidification, so it is not susceptible to frost and is fire-resistant. However, it also has some disadvantages.
HACs are expensive to manufacture and lose their relative strength under humid and high temperature conditions. In addition, due to the high loss of heat during the condensation process, it is not suitable for large-volume concrete projects. Despite its limitations, HAC is still used in some applications. Because of its chemical resistance, it is suitable for sewer and marine infrastructure. It is also used in refractory concrete that requires high strength at high temperatures, as well as in cold areas where rapid strength development is required。
