How to choose degradable RECPs (Rolled Erosion Control Products).
When choosing rolled erosion control products it can be overwhelimg. There are a wide variety of nettings and fibers to choose from. A few things to consider that will ensure you get what you need and achieve the results that you want.
A good installation of erosion control blankets will keep seeds and soil in place and provide a micro-climate where moisture is retained and the surface temperature fluctuations are reduced, benefiting the germination and expression of the desired vegetation.
When selecting an erosion control blanket there are two main performance criteria to consider: Functional longevity and tensile strength.
The functional longevity will determine how long a product typically lasts in the environment. Climate and weather conditions can certainly make a difference and should be considered. A blanket that will last through initial vegetation expression and degrade as the plants take over is ideal. Single net straw products usually degrade the fastest, followed by blends of straw and coconut fibers, with coconut fiber lasting the longest. Manufacturers also use different netting materials that will accelerate or slow down a material's degradation. With UV degradation additives can facilitate the rapid degradation of synthetic netting materials for locations where vegetation establishes rapidly and residual netting in not desired.
Manufacturers also have developed completely biodegradable netting materials that have no synthetic elements that have been used successfully for many years in all climates.
The next consideration when selecting a degradable RECP is the product strength. Described as tensile strength, one should consider the length and steepness of the slope or in a ditch or channel application—the expected shear stresses the product will be exposed to. In slope applications as material becomes wet with rainfall, it will become heavier and gravity will be exerting force pulling the material downward. The combined netting, stitching, and fiber-matrix must be able to resist these forces without tearing. In a concentrated flow the weight of the water with gravity pulling on it will exert significant shear stress that a product must be able to withstand.
Manufacturers will publish the performance capabilities of their materials. Look for a functional longevity that will last throughout the time necessary for plants to germinate, express and establish. This will prevent erosion while vegetation is establishing. Consider the climate and its effects on the vegetation growth in your product selection. Also make sure to give consideration to the material tensile strength. You should be able to find the test data that will allow you to confidently select materials that will withstand the expected forces that are expected.
Function longevity and tensile strength are the two characteristics that will allow product selection for most applications. For more information consult manufacturer's product information. This information is all readily available on our website for ECBVerdyol's products!
Author: Alex Zimmerman