From the GMA Techline
Subject: Filter bags for ditch checks We are looking for a type of geotextile fabric to specify for filter bags for temporary ditch checks. What we are looking for is a type of geotextile fabric that allows some water flow, probably about the same size opening as an FF-type fabric that doesn’t degrade in the elements—water, sunlight, heat, cold, etc. We need a bag that retains its strength for an entire season (or longer) so it can be moved around on a project and removed at the end of the project without leaving a mess.
Currently the most-common material being used is burlap that rots in the water. [I am aware of a company that] is using a nylon material that they are getting good results with, getting 12 to 18 months life out of these bags. Do you believe that this is a good material for us to use or do you believe that there are better geotextiles out there for this? (Engineers from Wisconsin)
Reply: Clearly burlap will not work for any time frame longer than a few months, depending on the climate and temperature. Most sandbags today are made from woven slit-film polypropylene fabrics. They give excellent strength-to-weight ratios and are relatively low cost, certainly when compared to woven monofilament fabrics.
Regarding durability, the antioxidants used in the formulation are of paramount importance. The test in this regard is a laboratory weatherometer that gives good insight into the anticipated lifetime of the material. Contact manufacturers directly [for more information]. Geosynthetics magazine’s annual Specifier’s Guide is also a good source in this regard.