Posted by Scott Hackett on Wed, Jul 06, 2011 @ 2:03 AM
Why the Stratacell is made of Recycled Plastic
“Is the Stratacell made of recycled plastic? I see… Why is that?”
This question often arises when discussing the Citygreen® Stratacell™, and it is a valid question. For all those wondering about the recycled properties of this cell, please read on….
The Stratacell is a very highly engineered module that owes much of its incredible strength to a unique design (subject to numerous patents). So strong is this design, that the base model Stratacell (Series 30) has an ultimate strength in excess of 300kPa without relying on any steel bars (subject to corrosion), or glass reinforcement, or virgin resins. This module is 30% stronger than any comparable large soil cell, and is made entirely from recycled Polypropylene. The top model Stratacell (Series 60) has an ultimate strength of 600kPa, and is manufactured from a unique blend of recycled PP and glass fibre. Capable of withstanding heavy traffic loads, the Series 60 StrataCell is the world’s strongest large soil cell by a huge margin.
Stratacell modules are crush tested during manufacture as part of the rigorous quality control standards required by Citygreen. Whilst FEA (Finite Element Analysis) computer load testing was also conducted during the initial design stages to project the loading capacity laterally and vertically, physical laboratory tests were then used to clarify the cells actual loading capabilities. This physical load testing is part of an ongoing development and research program, and is the only true measure of structural integrity. Stratacell modules are made using 100% recycled polypropylene, and have the highest structural integrity of any large soil cell.
The use of recycled polymers has in no way compromised the structural integrity of this large soil cell, and completes the absolute definition of long lasting green infrastructure in the built environment.
When developing the Stratcell, our aim was to take the best factors from both traditional structural soil and suspended pavement technologies, and incorporate them into a system that is environmentally friendly, exceeds global loading standards (including H-20) with close proximity of the pavement to imitate a trees natural root plate pattern, and ultimately create sustainable systems for healthy trees in urban environments such as plazas, public open spaces, parking lots, and streets.
As the world’s strongest large soil cell, Stratacell has been subjected to extraordinary laboratory tests, including fatigue testing. In one test a university applied a load of 8.6 tonnes to a Stratacell tower 10,000 times. The tower was then crushed to measure whether the ultimate load had been diminished by the cyclic loading. The high strength modules had lost no strength, verifying the design strength of this remarkable system.
Stratacell unique patented design geometry provides a high strength skeletal matrix that occupies less than 6% of the total pit volume. The use of virgin polymers would contribute almost nothing to the modular strength, provide no appreciable plastic reduction, and sacrifice important goals of the Green Building philosophy.
No Compromise with Stratacell
Citygreen has taken a totally uncompromising approach to the development of Stratacell system. Every design element is finely balanced and refined using cutting edge engineering software in the hands of highly qualified design experts. Only one outcome was ever deemed acceptable – the world’s strongest large soil cell, using 100% recycled polymers, with huge volume reduction for reduced shipping costs.
Lower Shipping Costs
An integral part of the Stratacell design brief (and an important element of the global patents) is the nesting function for shipping. Since the inception, these special modules have been designed to reduce reliance on fossil fuels by maximizing freight volume reduction, to suit standard skids and shipping volumes. Another crucial factor has been a reduction in wasted packaging material.
The use of virgin resins in a product for the Green Building Industry has never been a part of the Stratacell development program. Virgin plastics have an unacceptably high level of embodied energy, whereas recycled waste plastic into an engineering grade product starts with a clean sheet as recognized by industry and the Green Building Council.
Citygreen Stratacell system qualifies your project for generous contributions towards LEEDS certification, with recycled content being a high contributor. Contact Citygreen for a copy of the full report.
We anticipate spreading the knowledge behind our green building systems and further supporting environmentally sound urban development. Our vision embraces a world where sustainable green space is within reach of every person, every day.