Recycling of Oily Sludge as a Roadbed Material Utilizing Phosphogypsum-Based Cementitious Materials

Table 4

Chemical compositions of materials (wt. %).

Precursors	SiO2	CaO	SO3	Al2O3	Fe2O3	Mg2O	Na2O	TiO2	P2O5	MnO	LOI
PG	4.65	30.85	31.85	4.20	—	0.24	0.32	0.20	3.22	—	2.27
OPC	27.21	53.44	2.38	6.49	4.43	1.69	2.09	—	—	—	3.75
FA	50.01	5.61	0.58	32.61	4.44	0.98	0.59	1.06	0.27	0.07	22.94
SF	91.34	1.45	0.31	1.25	1.32	1.14	1.02	—	—	—	2.17

LOI: loss on ignition at 1000°C.