Rheological Evaluation of Modified Bitumen by EVA and Crumb Rubber Using RSM Optimization

Table 1

Characteristics of unmodified bitumen.

	Classical test				DSR test		BBR test
	Softening point (°C)	Penetration (dmm)	Ductility (cm)	Viscosity at 135°C (Pa·s)	Temp for /sinδ ≥ 2.2 kPa (°C)	Temp for /sinδ ≤ 5000 kPa (°C)	Creep stiffness	m-value
Unmodified bitumen	47.2	93	+100	0.41	62.21	22	70	0.36