Table 1 Chemical compositions of the binder materials.

Silica (SiO₂)

36.0

20.2

93.4

50.24

Alumina (Al₂O₃)

10.5

4.7

0.42

28.78

Iron oxide (Fe₂O₃)

0.67

3.0

0.52

5.72

Calcium oxide (CaO)

39.8

61.9

1.91

5.86

Magnesium oxide (MgO)

7.93

2.6

–

1.74

Sodium oxide (Na₂O)

0.27

0.19

0.25

0.20

Potassium oxide (K₂O)

0.80

0.82

0.79

0.84

Sulfur trioxide (SO₃)

2.1

3.9

0.34

0.51

Loss on ignition

3.0

1.9

2.3

2.8

Specific surface area (m²/kg)

487^a

453^a

13,000^b

322^a