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What are Bogue’s Equations?

These equations were put forward by Bogue to calculate the potential composition of cement (based on content of different oxides). These are:-

C₃S = 4.07 CaO – 7.60 SiO₂ – 6.72 Al₂O₃ – 1.43 Fe₂O₃ - 2.85 SO₃

C₂S = 2.87 SiO₂ -0.754 (3 CaO.SiO₂)

C₃A = 2.65 Al₂O₃ – 1.69 Fe₂O₃

C₄AF = 3.04 Fe₂O₃

(above equations only valid when A/F ≥ 0.64 )

Illustrative Example:

Percentage of oxide as per Oxide Analysis

Calculated Compound Composition

SiO₂ 20.6
Al₂O₃ 5.07
Fe₂O₃ 2.90
CaO 63.9
MgO 1.53
K₂O 0.73
Na₂O 0.15
SO₃ 2.53
LOI 1.58

C₃S = 4.07(63.9) – 7.60(20.6) – 6.72(5.07) – 1.43(2.90) - 2.85(2.53) = 58.1
C₂S = 2.87(20.6) – 0.754(58.1) = 15.6
C₃A = 2.65(5.07) – 1.69(2.90) = 8.5
C₄AF = 3.04(2.90) = 8.8
Bogue Potential Composition:
C₃S: 58%
C₂S: 16%
C₃A: 9%
C₄AF :9%

FAQs

What is significance of Bogue’s Equations?

How do the results of Bogue’s equations compare with those obtained in X-Ray diffraction?