In 2010, the National Park Service began work to update and expand the Marin Headlands, an outlook of the Golden Gate National Recreation Area, famous for its unique geology. GraniteCrete was chosen as the paving material for the job due to its low impact, its porosity and its permanence: GraniteCrete requires minimal maintenance to last beautifully for decades.
Marin Headlands’ characteristic red-brown topography formed millions of years ago by lava spilling from vents and mixing with radiolarians (microscopic protozoans). The paving upgrades needed to blend seamlessly with the surroundings to preserve “the crown jewel of the Golden Gate National Parks,” so the National Park Service required the color of the new paving to match the existing native material. This expansion also required excavation of the surrounding hillside to allow for a widened roadway and vista turn outs.
All of this presented GraniteCrete with a unique challenge: None of GraniteCrete’s four standard colors exactly matched the deep red-brown color characteristic of the area terrain.
As a leader in innovation and sustainability in surfacing solutions, GraniteCrete worked with the architects to solve two issues as sustainably as possible, the color matching and the disposal of the excavated material.
Normally, GraniteCrete admixture is mixed with decomposed granite brought in from an outside quarry. However, for this project, GraniteCrete Admixture was mixed with the on-site material that was being excavated – the trademark red-brown cherts for which the area is known. In a process that had never before been attempted, the excavated cherts were sieved to GraniteCrete’s specifications and then combined with GraniteCrete Admixture to create the perfect color, sustainably.
If the on-site material had not been used, twenty-one truck loads would have been needed to transfer the materials off site for disposal, and another twenty-one needed to bring in new decomposed granite! The use of the on-site material saved gas, reduced the wear to our roads, cut down on emissions, and saved approximately $20,000 in trucking costs.
What was done at the Marin Headlands was unprecedented in the aggregate stabilizing industry. GraniteCrete is proud of its part in this
sustainable and environmentally successful project and we encourage you to visit this natural wonder. It is truly the crown jewel of the Golden Gate Recreation Area. See it for yourself and bring a picnic lunch!
GraniteCrete offers 4 standard colors, along with custom colors, each made with organic toxin-free pigments. Combined with natural decomposed granite, GraniteCrete is your permanent, permeable and natural paving solution for trails, walkways, driveways, parking areas, and yes, even bocce ball courts!