A Longitudinal Study of Playground Surfaces to Evaluate Accessibility - Final Report

Shredded Rubber

Shredded Rubber (SHR) is most often the byproduct of recycled tires shredded into particles, crumbs or nuggets, sized 3/8 to 7/8 inches.  The surface material used as a play safety surface has gained some popularity as a means to reuse tires.  During pilot site visits and testing of the study protocol, the research team found sites with SHR containing tramp metal.  Some studies have shown mixed findings on the health effects and environmental impact for use (California Office of Environmental Health Hazard Assessment, 2007).  There is a lack of research data on the ability of the SHR to perform as an accessible surface when installed in public park playgrounds.  A loose fill surface, similar to EWF, SHR may experience many of the same issues such as undulation of the surface area and displacement resulting in inaccessible routes for play areas.  Observational research outside of this study has shown the undulation and instability of the particles to be difficult for people with mobility impairments to traverse.  Shredded rubber manufacturers and the member association did not respond to the research team requests to participate in the NCA longitudinal study.  As such, public park playground installations with shredded rubber surfacing are not represented in this study.  The inclusion of sites surfaced with shredded rubber would have been beneficial to the study in order for researchers to compare this loose fill material with the only other loose fill material in the study, namely EWF.  A greater examination of the tramp metal in the particles may help to determine if there was an effect on the use of assistive devices such as wheelchairs, walkers, canes or crutches.  The firmness and stability of the product material could have been studied much more thoroughly at real sites and analyzed with controlled laboratory findings such as that for ASTM F1951‒99.  Comparison of the two loose fill materials, EWF and SHR, may provide playground owners with a better understanding of how compaction during installation can affect the undulation and usability of the surface in the accessible routes.  Comparison of the two materials may also give more guidance on the specific needs for maintenance of loose fill particles used for the accessible route.