Characterization of permeable pavement materials based on recycled rubber and chitosan

• Composite materials for use as permeable pavers were prepared from chitosan and tire crumb.
• Compressive strength and hydraulic conductivity similar to conventional permeable pavers was achieved.
• Sorption capacity of dissolved zinc from water was as high as 0.63 mg per gram of chitosan.
• Unlike other permeable pavements, properties were not strongly dependent on binder content.
• Material properties and morphology were dominated by the concentration of chitosan solution used.

A variety of composite permeable pavement materials were prepared from crumb rubber embedded in a matrix of the biopolymer chitosan, which is a waste product of the seafood industry. We have characterized the hydraulic conductivity, mechanical properties, and the capability of these materials to remove particulate and dissolved pollutants (including zinc) from water. The dependence of material properties on process parameters such as binding polymer content differs from what is typical of binder-based permeable pavement, due to the mechanism by which chitosan is introduced, and in many cases the stability of the composite material increases with decreased binding polymer content.