TRM
TRM
(OP)
Has anyone had any experience with turf reinforcement mats? i am interested in using them instead of the conventional rip-rap but dont quite have the confidence in them yet.
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RE: TRM
In general, TRMs provide long-term/permanent reinforcement and erosion control. Often they are composites, with biodegradable materials (used to establish vegetation) mixed with synthetics (used to provide stability against erosive forces). The degradable-nondegradable construction is largely determined by site-specific needs. Most TRM manufacturers offer a wide-range of products and have design personnel to help you in your selection.
Again, start with ECTC. It's an excellent organization.
-cK
Christopher Kelsey, editor
GFR magazine
gfr@ifai.com
www.gmanow.com
RE: TRM
They both do the same thing as the biodegradable portion (straw or coconut fibre) of RECB's do not promote growth in themselves, they just offer protection from wind and water so that growth can occur without erosion. This does have the effect of faster growth. Then they biodegrade (photodegrade for the netting) so that nothing is left behind.
TRMs also do the same thing but offer permanent root reinforcement in higher water flow situations or steeper slopes. They can also be used without vegetation in place of riprap to slow water velocities (such as storm water drainage channels).
cskelsey is right that you can check with manufacturers for properties and applications as well as the ECTC. Many companies offer design CD's which ask for many parameters then output various material choices.
RE: TRM
Turf reinforcement mats tend to be celled (honeycombed) synthetic materials which are placed prior to topsoil placement and seeding. The topsoil then fills these cells when placed. These mats are considered to be permanent topsoil slope reinforcement as they last well over 5 years provided they are covered completely and protected from direct sunlight and weathering. They are usefull where you have steep slopes but ample growing season and a good seedmix to ensure a successful catch.
Erosion control blankets (synthetic or otherwise) are installed over topsoil which has already been seeded and offer protection to the area for a couple of seasons max to allow for a successful catch. The drawback to these blankets is that you aren't able to return the following season to reseed if you don't have a successful catch. I have personally used synthetic erosion control blanket in place of rip-rap in ditches which have a highly erodible soil type (silty sand)and severe grades(+3%)and intermittent flow. It worked great.
I would not suggest using this material in place of rip-rap at culvert inlets/outlets or any ditch which is expected to carry water constantly. You won't be able to get anything to grow and all blankets will degrade if exposed.
Cheers
RE: TRM
We've used both ECB's and TRM's on long, steep slopes. They've worked well and the TRM's have provided excellent long term protection. ECB's and TRM's for channel protection can also be an excellent choice. But in either case it is necessary to pay attention to the details of construction both in preparing your specifications and ensuring that the construction is performed properly.
A good vendor supplied design program is provided by North American Green. NAG also has good installation details, specifications and other design guidance information.