Benefits of High Alumina Cement
High Alumina Cement refers to an inorganic material that develops a condensed texture if it is connected with water. This construction materials contains an outstanding refractory, rapid curing property and resistance to chemical reactions. High Alumina Cement is formed by grinding clinkers which are developed with calcining bauxite and lime. The bauxite refers to a raw material of aluminium. It should be remembered that total alumina content must remain below 32 percent and the proportion by weight of alumina to the lime must remain amid 0.85 and 1.30. This cement is called by the trade names of Cement Fondu in England and Lumnite in America.
Given below some of the striking features of High Alumina Cement:
Contains low pH
Contains strong refractoriness
Offers high strength in sulfuric acid
It solidified instantly
It is less reactant as compared to alumina or hydraulic lime
It functions as a bonding material if included in refractory castables as it develops ceramic bond at high temperatures
Offers good resistance power against chemical erosion. Therefore, it is extensively applied in building water pipes, sewage pipes, factory drains, coastal constructions and in factory chimneys.
Benefits of High Alumina Cement:
1. The time required for primary setting of this cement is over 3.5 hours. The required time for final setting is around 5 hours. So, it offers more time for mixing and placing operations.
2. It can withstand high temperature.
3. It evolves great heat throughout setting. So, it provides good resistance power against frost.
4. It withstands the reaction of acids in a superior manner.
5. It sets rapidly and achieves greater ultimate strength in quickest possible time. After one day, its strength becomes about 40 N/mm2 and about 50 N/mm2 after 3 days.
6. Its setting action is primarily based on the chemical reactions and therefore it is not essential to grind it to fine powder.
Drawbacks of High Alumina Cement:
1. Proper care should be taken so that it can’t be contacted with even traces of lime or ordinary cement.
2. It cannot be applied in mass construction because it evolves great heat as it sets quickly.
3. It is expensive