High Alumina Cement is a rapidly hardening, high-strength, high-temperature resistant, and corrosion-resistant cementitious material.
Its main characteristics are high early strength, high-temperature adhesion, and corrosion resistance.
The main component of high alumina cement is calcium aluminate, with an alumina content of about 50%. It is a hydraulic cementitious material formed after grinding.
High alumina cement, also known as refractory cement or aluminate cement, is an important part of high-quality refractory materials.
1. Early strength characteristics: its early strength increase rate is far more than rapid hardening Portland cement, which is suitable for emergency repair projects, but its late strength will be reduced, and its use is limited in structural engineering.
2. High hydration heat: Early cement has a high heat release during hardening, and compared to Portland cement of the same grade, it can release 70-80% of the total hydration heat in just one day. Due to several types of heat release, it is suitable for low-temperature curing of concrete engineering.
3. High alumina cement is wear-resistant and corrosion-resistant, and can work stably in acidic and alkaline environments.
4. Good high-temperature resistance: able to maintain stable physical and chemical properties in high-temperature environments. High alumina cement can be used as a bonding material for heat-resistant concrete and configured as heat-resistant concrete.
High alumina cement is generally divided into two categories:
one is the most commonly used high alumina cement, also known as bauxite cement, with an alumina content of about 50%; According to the flexural and compressive strength at three days of age, it can generally be divided into four grades: CA 425, 525, 625, and 725.
The other is high alumina cement (also known as pure calcium aluminate cement) with alumina content of 60%, 70% and 80%, which is mainly used to prepare amorphous refractories. Its refractoriness increases with the increase of alumina content.
(1) Used for blending amorphous (unshaped) refractory materials.
(2) Blend special purpose cement such as gypsum alumina expansive cement and self stressing cement.
(3) Used for projects with special needs such as emergency construction, repair, sulfate resistance, and winter construction.
