Careful evaluation goes into any prospective materials that might be used in the manufacturing of our green brick. Many potential waste stream products have been reviewed, but few meet all Green Leaf Brick criteria. To be considered for composition in a Green Leaf Brick, materials need to have close proximity, be readily available, possess excellent ceramic properties, and meet our safety in handling criteria - all while contributing to our aesthetic focus. To date over 25 different recycled raw materials have been approved for use in these brick. There are both foundational materials (those used in every Green Leaf Brick which make up the core of the brick, providing the desired recycled contents and giving the brick its outstanding ceramic properties), and the aesthetic materials (those used to affect the color or texture of the brick).
Green Leaf brick is contstantly seeking new waste streams for our composition; we have evaulated hundreds of potential products but very few meet our criteria. All inputs used in making Green Leaf Brick must be: readily available, viable in our composition, waste stream sourced, non-toxic and processed in a manner that meets our sustainable focus.
A variety of pre and post consumer waste streams are implemented in our composition. These materials include overburden shale and clay deposits; no new lands are mined in securing our plastic earthen base. Another primary family of materials are virgin ceramic scrap and refuse that is taken directly from the manufacturer to the brick yard. Incorporated into this mix are many industrial manufacturing by products, such as iron oxides derived from metal processing and mine water clean-up operations, recovered and recycled glass from consumers and sewage wastes.
Combining these materials is no easy task and difficult in contemporary brick making operations. We are approached constantly by entities with waste streams, requesting evaluation for use in making our products. Through many years of experience, we have ascertained what could possibly work and also what will not be viable in production. To date we have taken in excess of 30,000,000 lbs of viable refuse, but have rejected the vast majority of offerings because they do not meet our full, sustainable program criteria.
Green Leaf Brick are manufactured to meet the specifications for FACING BRICK as defined by ASTM C216 standards. These specifications cover brick intended for masonry use as facing brick or for structural applications.
ASTM C216 gives standards which qualify a brick as being of a specific grade or quality. It also describes and sets limits for certain parameters, such as coring or hole sizes, and chippage. As an example, under ASTM C216 brick can have a maximum core volume of 25% of the bed.
There are classifications for the grade of the brick, being either moderate weather (MW) or severe weather (SW) rated. Green Leaf Brick are classified as Severe Weather (SW), the highest performance classification for weather resistance. Brick are also categorized by their allowable sizing tolerances. Green Leaf Brick are classified as type FBS, meaning that permissible variations in sizing on a standard brick are +/- 1/4" on the longest length. For some applications, FBX classifications are obtainable.
Availability of the selected materials is important for long term viability. Some materials are dismissed because a long term supply is not stable. Smaller components of the brick can be interchangeable, but for the most part, consistent input supply is expected with all of the materials Green Leaf Brick uses.
Not every proposed waste stream can be used in making our product; the vast majority of perspective waste products are rejected. Flyash, for example, is readily available but cannot be used in any appreciable quantity making fired masonry brick; it weakens the body and raises absorption too high. Other materials can only be used in small quantities. Some materials are more plastic and help with forming, while others tend to melt and help with the fired properties of the brick. Finding the proper blend of materials to make the highest quality brick, while providing the most positive environmental impact has been our ultimate goal.