Effect of Zn/Al Layered Double Hydroxide Containing 2-Hydroxy-4-n-octoxy-benzophenone on UV Aging Resistance of Asphalt

Table 3

Physical properties of asphalt binders before and after UV aging.

Samples	Unaged			UV aged
	Pristine asphalt	modified asphalt	Zn/Al-HNOB^−-LDH modified asphalt	Pristine asphalt	modified asphalt	Zn/Al-HNOB^−-LDH modified asphalt
Penetration (25°C, dmm)	67	61	64	88	87	97
RP^a (%)	—	—	—	32	42	51
Ductility (10°C, cm)	31.8	27.2	29.3	43.2	40.0	45.7
RD^b (%)	—	—	—	36	47	56
Softening point (°C)	51.2	55.6	53.8	59.3	62.5	59
SPI^c (°C)	—	—	—	8.1	6.9	5.2
Viscosity (135°C, Pa·s)	1.52	1.95	1.83	3.83	4.64	3.95
VAI^d (%)	—	—	—	152	138	116

Residual penetration (RP) = ((aged penetration – original penetration)/original penetration) × 100%.
^bResidual ductility (RD) = ((aged ductility – original ductility)/original ductility) × 100%.
^cSoftening point increment (SPI) = aged point increment − fresh point increment.
^dViscosity aging index (VAI) = ((aged viscosity value – fresh viscosity value)/fresh viscosity value) × 100%.