SAP/WCO Composite Modified Asphalt

Foam-induced viscosity reduction

Synergistic modification of asphalt via SAP water-release micro-foaming and WCO oil film delay improves rheological performance across high, intermediate, and low temperatures, with a controllable foaming process.

Qiao, Qicai · Gao, Yang · Zhang, Xiao · Gao, Yang · Zhang, Wenju · Su, Jinfeng · Xue, Yao

Construction and Building Materials 2025

Advantages

SAP reduces viscosity via water-release-induced micro-foaming, WCO delays foaming due to oil film, synergistic viscosity reduction

At high temperatures, SAP significantly increases complex shear modulus G* and rutting factor G*/sinδ, with more pronounced improvement at higher SAP dosages

At intermediate temperatures, SAP improves fatigue factor and extends fatigue life based on LAS testing, WCO further enhances fatigue resistance

At low temperatures, WCO improves thermal cracking resistance, combined with SAP shows synergistic enhancement