Effect of Agricultural Crop Wastes as Partial Replacement of Cement in Concrete Production

Table 5

Chemical compositions of rice husk ashes (RHA).

Authors	Chemical compositions (oxides %)									SiO2 + Al2O3 + Fe2O3
	SiO2	Al2O3	Fe2O3	CaO	MgO	SO3	K2O	Na2O	LOI
Khan et al. [56]	86.80	0.895	2.435	0.45	0.55	—	—	—	2.5	90.08
Antiohos et al. [57]	86.50	0.92	0.56	1.12	1.30	0.05	1.58	0.43	6.3	87.98
Raheem and Kareem [58]	82.14	1.34	1.27	1.21	1.37	0.17	2.09	0.14	—	84.75
Zareei et al. [59]	86.70	0.04	0.61	0.39	1.32	9.8	0.01	—	—	87.38
Krishna et al. [60]	76.8	0.41	1.045	0.93	0.27	—	2.64	0.1	—	78.22
Abiodun and Jimoh [61]	61.33	2.20	8.43	6.53	2.33	—	11.90	2.53	—	71.97
Salas et al. [62]	90.00	0.68	0.42	8.14	0.35	—	—	0.32	—	91.10
Faried et al. [13, 16]	70.36	1.54	0.68	4.51	1.35	3.23	8.73	1.09		72.58