Early and Late Strength Characterization of Portland Cement Containing Calcined Low-Grade Kaolin Clay

Table 1

Properties of Portland cement and raw clay.

Property	PC	Raw clay
Physical
Fineness (m^2/kg)	401.7
Specific gravity	3.13
Chemical
SiO2 (%)	20.49	59.7
Al2O3 (%)	4.26	25.53
Fe2O3 (%)	3.14	5.22
CaO (%)	63.48	0.16
MgO (%)	2.11	1.37
SO3 (%)	2.9	0.07
Na2O + K2O (%)	0.49	2.41
LOI (%)	2.2	4.5
Mineralogy
C3S (%)	56
C2S (%)	15
C3A (%)	6
C4AF (%)	9
Particle size distribution (%)
Clay (<2 μm)		28.4
Silt (2 μm–0.05 mm)		19.5
Sand (0.05 mm–2 mm)		52
Gravel (>2 mm)		0.1