Technical Details

GraniteCrete and green building practices (LEED)

The United States Green Building Council created the Leadership in Energy and Environmental Design (LEED) rating system. The system encourages and accelerates global adoption of sustainable green building and development practices. LEED is a nationally accepted benchmark for the design, construction and operations of high performance structures. Industry designers, architects, managers, lenders, government officials and many others use LEED to help transform a conventionally constructed environment to a sustainably constructed one. State and local govenrmnets are adopting LEED points for a project in the following categories: sustainable site development, water conservation and material selection.

Storm water management

The demand for clean water will only increase. Traditionally constructed impervious surfaces channel water to storm runoff paths, collecting toxic substances like oil and fertilizer along the way. These systems drain water away from local aquifers and towards standing or open bodies of water, sometimes miles away. GraniteCrete is completely permeable and allows water to return through the soil into the local aquifer.

Up to 30º slope

Although ADA approved paths should not exceed 5º slope GraniteCrete can be installed on slopes up to 30º, eliminating the need for traditional erosion maintenance and under-trail percolation pipe. Back to top.

Exceeds OSHA (Occupational Safety & Health Administration) standards for surface friction

GraniteCrete paving provides a high friction, non-slip surface. The American Society for Testing and Materials (ASTM) coefficient of static friction for GraniteCrete is: dry = .84, wet = .62. The ratings for both wet and dry exceed the United States Occupational Safety and Health Administration (OSHA) recommended walking surface minimum coefficient of static friction of 0.5 as stated in the 1990 Americans with Disabilities Accessibility Act guidelines. Click here to see the independent laboratory test results page. Back to top.

Installation details

GraniteCrete is installed on trails and paths for pedestrian use as a three inch thick layer above a compacted 4" sub grade of base rock. GraniteCrete is even tough enough for light and heavy vehicular traffic. For vehicular traffic it is installed as a four inch layer over a six inch sub-grade of 95% compacted base rock. These construction details are similar to conventional asphalt or concrete installation. The main difference is that GraniteCrete is staill completely porous allowing trails and large parking areas to absorb water on the spot. Rapid absorption eliminates standing water puddles and, because of the porosity, paths don't have to be crowned. This can solve tricky drainage problems in situations where building codes require all step risers to be at a consistent height. These codes can also require the paving around surronding structures to drain at a minimum of 2% away from their base. Since GraniteCrete is porous, the drainage can actually occur in the sub-grade layer. That is not possible with traditional concrete or asphalt paving. Back to top.

Heat Islands

Conventional parking lots and asphalt streets are major contribtors to urban heat islands. Asphalt is particularly heat abosrbing and can get up to 40º F hotter than the surronding air. The lighter a paving material is in color, the more it reflects the sunlight, absorbing less heat. GraniteCrete is available in six organic light colors: Natural, Brown, Adobe, Sand, Red New Brick, and Red Old Brick. If your project requires a custom shade, GraniteCrete can be colored to match your project's specifications. All colors have a high Albedo value. Back to top.

Albedo values

Albedo or solar reflectance is the ratio of reflected solar radiation to the total amount that falls on that surface known as incident solar radiation. Albedo values range from 0, for perfect absorbers (dark paving) to 1, for perfect reflectors (light paving). An Albedo value of 0.8 means that 80% of all the energy striking a reflecting surface is reflected back into the atmosphere and only 20% of the energy is absorbed by the surface. Therefore, paving with high Albedo values assists in reducing heat islands. Back to top.

Installation methods

Measurements

Base Rock: sufficient for 6" depth compacted at installation site.

GraniteCrete: One cubic yard of decomposed granite and three (85 lbs.) sacks of GraniteCrete Admixture combined covers 90 square feet at 4" thickness. Back to top.

Pre-Installation

1. Compact base rock on entire install site to even 6" depth.

2. Due to the limited size of most cement mixers, it will be necessary to prepare GraniteCrete in "batches." There are approximately ten (10) batches per single cubic yard of GraniteCrete. Prepare each batch as follows:

1. Mix eleven shovelfuls of DG to one shovelfull of GraniteCrete Admixture
2. Mix thoroughly and continue moistening until GraniteCrete begins to marble or clump together. Squeeze the mixture in your fist and open your hand. If the mixture stays in a clump, it is ready for installation.

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Installations

1. Wheelbarrow each batch to the installation site and fill the installation site approximately 3/4" above the desired finished grade level then rake the surface until the surface is even. Do not allow GraniteCrete to dry. You may cover with tarp if necessary.

2. Compact surface to desired finished grade level. Compaction is complete when no foot marks appear.

3. You may walk on GraniteCrete immediately after installation, however, like concrete, GraniteCrete gets stronger with time. For tips & tricks and answers to frequently asked questions, visit the faqs.html page within this site. Back to top.

Light Traffic Areas - Garden Paths, Steps, Patios - areas limited to pedestrian use

Excavate seven inches from final grade in area to be installed. Install a header board along edge. (Header board may be eliminated by trenching deeper along edges for additional base rock - see below). Install four inches of Class II base rock and compact to 95% compaction. Mix GraniteCrete Admixture sacks with decomposed granite or any 3/8 minus aggregate as directed. Install three and three quarter inches of GraniteCrete and compact using hand tamper, vibre roller, or vibre plate. The three quarter additional inch allows for a finish compaction of three inches of GraniteCrete. A six cubic yard concrete mixer can be used for small installations. A volumetric concrete truck can be used for medium to large installations. We have even produced GraniteCrete with large drum concrete trucks.

Heavy Traffic areas - commercial use, utility and golf carts paths, off street parking, etc.

Excavate ten inches from area to be installed. Install a header board along edge. Install six inches of Class II base rock and compact to 95% compaction. Mix GraniteCrete Admixture sacks with aggregates as directed. Install four and three quarter inches of GraniteCrete and compact. If no header board is desired, an additional twelve inch wide by six inche deep trench must be excavated along edges of area to be installed.

It takes three GraniteCrete Admixture sacks per cubic yard of decomposed granite.

Cost estimates

GraniteCrete is available through your locally licensed landscaping contractors and for do-it-yourselfers. GraniteCrete will soon be available in ready-mix bags at local landscaping supply stores. The product is easy to install and requires no rebar, special equipment or skilled knowledge to lay-in a professional grade surface on your first try. Back to top.

Composition

The mixture is protected as intellectual property. It is composed of natural materials manufactured from the fines that are by-products of quarried stone.

Trademark

"GraniteCrete" and "The Natural Path" are registered trademarks and currently patent pending. Back to top.