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Grand Rapids to Complete Replacement of Tree Grates with Permeable Paving Material03-30-15 | News

Grand Rapids to Complete Replacement of Tree Grates with Permeable Paving Material

Replacing rusted, broken iron tree grates with Porous Pave permeable paving material makes downtown sidewalks safer and streetscapes more attractive.

In its continuing effort to make its downtown more welcoming, and to support its sustainability initiatives, Grand Rapids, Mich. is completing the replacement of 750 old iron tree grates with Porous Pave XL. Manufactured by Porous Pave, Inc., this is a highly porous, durable and flexible pour-in-place surfacing material that is a proven solution for green stormwater infrastructure. An eco-friendly green building product, it consists of recycled rubber, stone aggregate and a binder.

The first phase of the project was completed in September 2014 before the annual ArtPrize event. The city had Porous Pave tree surrounds installed to replace 250 cracked and broken grates that presented the most serious tripping hazard in the three square miles of downtown. An additional 500 grates will be replaced by July 2015. "Porous Pave allows rainwater and air to get down to the tree roots," said Mark DeClercq, P.E., city engineer. "With its high rubber content and textured surface, Porous Pave is slip resistant and safer when wet than traditional metal tree grates."

Porous Pave XL is a hard, durable material made from 50 percent recycled rubber chips and 50 percent stone aggregate with a moisture-cured urethane binding agent. This materal infiltrates stormwater on site, decreases the volume and slows the velocity of runoff flowing into storm drains and storm sewers, improves water quality by reducing erosion and filtering out pollutants, and recharges groundwater. Porous Pave is engineered with 29 percent void space. For technical specifications, independent lab test results and distributor locations, visit www.porouspaveinc.com.