Effect of binder-aggregate ratio on the mechanical and functional properties of porous polyurethane cement mixture

Polyurethane mixtures are regarded as novel polymer pavement materials that can overcome the shortcomings of poor mechanical properties and loose particles of open-graded friction course (OGFC). Owing to its high strength after curing, polyurethane binder improves the mechanical connection at the aggregate-aggregate contact point, which effectively enhances the service performance of permeable pavement. However, the relationship between the binder content and the mechanical and functional properties of polyurethane mixture has not clearly understood yet. The objective of this study is to investigate the influence of the binder-aggregate ratio on the mechanical and functional properties using laboratory tests. Firstly, the effect of binder content on the mechanical properties of the mixture is examined by Marshall stability test, uniaxial compression test, and bending beam test. Secondly, the functional properties of the mixtures are characterised by Cantabro test, permeability test, computed tomography, and particle clogging test. Finally, the durability of the mixtures is characterised by hydrolysis resistance test and ultraviolet radiation degradation test. The results reveal that the content of binder has a significant impact on the mechanical and functional properties of the mixture. It is necessary to maintain a balance between the mechanical and functional properties.