The oxides present in raw materials when subjected to high clinkering temperature combine with each other to form complex compounds. The identification of major components is largely based on R. H. Bogues work and hence it is called as Bogues Compounds. They usually varied to get different types of Cements.

The four Compounds usually regarded as major compounds are listed in following table :

COMPOSITION OF BOGUES COMPOUNDS

Alite (C3S) : 25% to 50%

Belite (C2S) : 20% to 45%

Celite (C3A) : 5% to 12%

Felite (C4AF) : 6% to 12%

PROPERTIES OF BOGUES COMPOUNDS

C3S : Faster rate of reaction and contribute to EARLY STRENGTH, Immediate Stiffness (Hardening), Early Heat of Hydration, Does not resist Chemical attack.

C2S : Slow rate of reaction and contribute to ULTIMATE STRENGTH, Slow Stiffening (Hardening), Resistance to Chemical attack.

C3S & C2S : In combination provide 70% to 80% of most of the Strength.

C3A : Reacts very fast than Sulphates and does not contribute to Strength.

C4AF : Does not contribute to Strength.

C3A & C4AF : Hydrate rapidly but contribution to strength is Insignificant.

RATE OF REACTION

C3A > C3S > C2S

ACCORDING TO STRENGTH

C3S > C2S > C3A > C4AF

ACCORDING TO HEAT OF HYDRATION

C3A > C3S > C2S > C4AF