Research on Preparation and Performance of Clay-Based Shield Tunnel Nonsintered Bricks

Table 1

Chemical composition of main raw materials (%).

Name	Loss on ignition	SiO2	Al2O3	Fe2O3	CaO	MgO	R2O	SO3	Total
Shield muck	10.4	53.4	13.5	6.4	10.0	1.8	4.5	—	100
Cement	1.76	21.8	5.5	3.81	61.85	1.69	1.05	2.54	100
Fly ash	8.1	50.6	28.4	6.1	3.8	1.1	1.9	—	100