Effect of Hybrid Steel-Basalt Fiber on Behaviors of Manufactured Sand RPC and Fiber Content Optimization Using Center Composite Design

Table 1

Physical and chemical properties of cement.

Properties		Standard value	Actual value
Physical properties	Specific surface area (m^2/kg)	≥300	363
	Initial set (min)	≥45	128
	Final set (min)	≤390	183
Compressive strength	3 days (MPa)	≥23.0	31.5
	7 days (MPa)	≥52.5	59.6
Flexural strength	3 days (MPa)	≥4.0	6.1
	7 days (MPa)	≥7.0	9.0
Chemical properties	Stability	Qualified	Qualified
	Loss on ignition (%)	≤3.5	1.27
	MgO (%)	≤5.0	0.79
	SO3 (%)	≤3.5	2.40
	Insolubles (%)	≤1.5	1.01
	Cl^− (%)	≤0.06	0.009