Efficiency of Rice Husk Ash as Cementitious Material in High-Strength Cement-Admixed Clay

Table 1

Chemical composition of rice husk ash, Portland cement type I.

Chemical composition	Rice husk ash	Cement type I	Fly ash [28]
SiO2 (%)	93.0	20.2	42.1
Al2O3 (%)	0.17	5.40	21.0
Fe2O3 (%)	0.35	2.90	7.12
SiO2 + Al2O3 + Fe2O3 (%)	93.5	28.5	70.2
SO3 (%)	0.11	2.30	0.70
CaO (%)	0.91	63.8	14.8
MgO (%)	0.42	1.50	2.00
Na2O (%)	0.63	2.72	0–2
K2O (%)	2.82	0.30	0–5
LOI	4.70	2.00	7.31