Evaluation of Interfacial Adhesion Properties Between Nano-Modified Composite Polyurethane and Cement-Stabilized Macadam Based on Surface Free Energy

The non-excavation grouting technology of composite polyurethane materials provides an efficient and economical treatment scheme for deep-seated distresses of asphalt pavements. To quantitatively evaluate the bonding performance between composite polyurethane and cracks in cement-stabilized macadam base, Image J(v1.54p) (National Institutes of Health, Bethesda, MD, USA) image recognition was adopted to analyze the gradation at the interface of cement-stabilized macadam base mixture. The surface free energy theory was applied to quantitatively study the work of adhesion at the interface between three types of nano-modified composite polyurethane materials (G1-2, T-1 (0.1 wt% MWCNTs and 0 NanoSiO2@KH550), and TG-1 (0.5 wt% MWCNTs and 0.5 wt% NanoSiO2@KH550)) and cement-stabilized macadam mixture, and predict the interfacial bonding performance. The results showed the bonding performance order as T-1 > G1-2 > TG-1. In addition, the micro-interface between nano-modified composite polyurethane materials and cement-stabilized macadam base was analyzed via SEM images, revealing the bonding mechanism at the interface between them.