What is an Erosion Control Blanket (ECB)? An erosion control blanket (ECB), also known as the erosion control mat or fabric, is a material made to prevent soil erosion on slope surfaces, water channel banks, or other erosion-prone land surfaces. Natural and synthetic fibers are used to make these blankets. These mates are designed to provide temporary protection to the soil until vegetation can grow and take over the responsibility of erosion control.

The erosion control blanket acts as a barrier against water runoff, wind, and other erosive agents, thus helping to stabilize the soil and protect it from being washed away. The blanket is usually installed on bare soil surfaces in areas where some human activities (construction, road cuttings), landscaping, or other activities have disrupted the natural vegetation cover. The absence of a vegetation cover weakens the internal adhesive quality and integrity of the soil.

There are different types of erosion control blankets, and they may vary in material, thickness, and design. Some blankets are designed to degrade over time, allowing plants to take root and provide long-term erosion control. Others may be more permanent and provide a durable layer of protection.

Installation methods may involve securing the erosion control blanket to the soil surface using staples, nails stakes, or other means. The choice of erosion control blanket depends on factors such as the slope gradient, climate, and the intended duration of erosion control required.

Overall, erosion control blankets play an important role in preserving soil integrity, preventing sedimentation in water bodies, and promoting sustainable land management practices.

What is an Erosion Control Blanket made of?

An Erosion Control Blanket (ECB), also known as an erosion control mat or fabric, is typically made from natural or synthetic materials designed to prevent soil erosion. The specific composition can vary depending on the manufacturer and the intended application, but some common materials include:

  1. Natural fibers:
    • Coconut fibers (coir): Erosion control blankets often use coconut fibers due to their biodegradability and ability to provide effective erosion control. Coir blankets are environmentally friendly and break down over time as vegetation establishes.
  2. Synthetic materials:
    • Polypropylene: Some erosion control blankets are made from synthetic materials like polypropylene. These blankets are durable and provide effective erosion control. However, they may not be as environmentally friendly as natural fiber alternatives.
  3. Biodegradable materials:
    • Straw: Straw blankets are commonly used for erosion control. They are biodegradable and can be effective in preventing soil erosion until vegetation takes root.
  4. Blended materials:
    • Composite blends: Some erosion control blankets are made from a combination of natural and synthetic materials, offering a balance between durability and environmental considerations.

The primary purpose of an erosion control blanket is to stabilize the soil, protect it from water runoff, and promote the establishment of vegetation. The choice of material depends on factors such as the site conditions, the severity of erosion, and the desired environmental impact. It’s essential to follow manufacturer recommendations and specifications for installation and usage to ensure optimal erosion control effectiveness.

Types of Erosion Control Blankets

There are several types of erosion control blankets, each designed for specific applications and environmental conditions. Here are some common types:

1. Photodegradable Erosion Control Blankets

Photodegradable erosion control blankets typically have netting made from materials like plastic. The plastic contains UV stabilizers designed to stop functioning after a specific period. After that happens, those parts of the netting break down under exposure to sunlight. The parts of the netting that are not exposed to sunlight, though, may take much longer to degrade.

  1. Polypropylene or Synthetic Blankets: Made from synthetic materials such as polypropylene, these blankets provide durable and long-lasting erosion control. They are suitable for high-flow areas and can withstand various weather conditions.

2. Biodegradable Erosion Control Blankets

Biodegradable erosion control blankets typically contain natural fibers rather than plastics. The fibers break down into the natural environment, so these blankets are an excellent choice for projects where minimal disruption to the natural environment is a high priority. Depending on their composition, biodegradable erosion control blankets may break down in a matter of months, or the process may take a few years.

  1. Straw Blankets:
    • Single Net Straw Blankets: These blankets consist of a single layer of straw with a single netting layer. They are suitable for mild slopes and low-flow areas.
    • Double Net Straw Blankets: Similar to single net blankets, but with an additional top netting layer. This provides extra reinforcement and is suitable for steeper slopes and higher-flow areas.
  1. Coconut Coir Blankets:
    • Single Net Coir Blankets: Made from coconut fibers, these blankets offer excellent erosion control. They come with a single netting layer and are suitable for various slopes and soil types.
    • Double Net Coir Blankets: Similar to straw blankets, double net coir blankets have an extra layer of netting for increased stability. They are suitable for moderate to steep slopes and areas with higher water flow.
  2. Staple- or Stitched-Blankets: These blankets are made by stitching or stapling natural or synthetic fibers to a mesh or woven material. This stitching helps anchor the blanket to the soil and promotes vegetation establishment.
  3. Mulch Mats: Mulch mats are erosion-control blankets that incorporate mulch or other organic materials. These mats help retain moisture, suppress weed growth, and provide a stable environment for vegetation establishment.

3. Turf Reinforcement Mats (TRMs):

These are specialized erosion control blankets designed to provide long-term protection in areas with heavy water flow or wave action. TRMs often incorporate synthetic materials and allow for the establishment of turf or vegetation.

When selecting an erosion control blanket, it’s important to consider factors such as slope steepness, soil type, water flow, and environmental conditions to ensure effective erosion control and successful vegetation establishment.

Two common types of permanent erosion control blankets are Turf Reinforcement Mats (TRMs) and High-Performance Turf Reinforcement Mats (HPTRMs).

  1. Turf reinforcement mats (TRMs): TRMs typically contain a blend of synthetic fibers, nets, filaments and wire mesh bound together to form a durable blanket. TRMs may also have supplemental degradable elements, including straw, coconut fibers, wood and other forms of natural fibers to help provide the best environment for immediate soil protection and encouraging new vegetation growth. Typically, companies use TRMs for applications involving water control, such as in channels or ditches, on the sides of steep slopes, around the banks of streams, on shorelines and any other areas where there are strong erosive forces. These mats help protect the landscape, reinforce plant life and stabilize the soil.
  2. High-performance turf reinforcement mats (HPTRMs): HPTRMs are TRMs that can take on more heavy-duty jobs. They have a higher tensile strength and improved reinforcement for stabilizing and protecting topsoil. They can handle the most intensive erosion protection jobs in areas where there is little to no natural vegetation or where gravity, hurricanes or wave impacts increase the effects of runoff. Some of the environments where HPTRMs perform the best include steep slopes, structural backfills, high-flow water channels, pipe inlets and outlets, maintenance access areas, utility cuts, streams, banks, coasts, levees and stormwater systems.

Designs of Erosion Control Blankets

The matrix made of fibrous materials, such as straw, coconut, wood excelsior or polypropylene, are tightly woven together with structural netting or mesh to create a thick mat. Depending on the intended use and construction, different models of blankets have varying levels of weave and matrix density, durability and longevity.

In general, all erosion control blankets need to have a high level of porosity to allow for airflow and promote moisture retention and plant growth. However, they should still be thick and have a strong structure to protect and stabilize the topsoil they cover.

Blankets may have one, two or three nets madeeither of polypropylene or jute. There are also four varieties of netting strength, divided into categories:

  • Ultra Short-Term: The net backing on ultra short-term blankets decomposes the fastest. It should begin to break down about one month after installation and be 80% decomposed after three months of use. These may also be called accelerated blankets.
  • Short-Term: The netting on blankets in short-term blankets remains functional longer than ultra short-term blankets, but they’ll still decompose at a reasonable rate. They have the appropriate amount of UV stabilization to function through a regular growing season but break down entirely by the end of the period.
  • Extended-Term: Netting on extended-term erosion blankets typically have the durability to maintain soil integrity for two years. These blankets are composed of processed slow degrading natural or polymer fibers to extend their functional longevity longer than short-term blankets.
  • Long-Term: The net backing on long-term erosion blankets has the most extended lifespan. It has better UV stabilization than the lower levels, allowing it to remain active for up to two to three years before fully decomposing.

In addition to these categories, there are also the permanent erosion control blankets that don’t decompose and provide the longest-term solution available. Most mats have netting on both sides, in which case the fiber materials are contained between the netting layers. The double-sided design ensures the fibers remain securely attached and don’t move away from the original placement site.

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