Special Geosynthetic Properties and MARV Values

The following are the special physical and performance geosynthetic properties required in the design described. These properties must be stated as Minimum Average Roll Values (MARV) with the required test methods. MARV is the smallest average value obtained from each roll tested. Rolls must have average values greater than the recommended value for a given type of test. MARV certification can be obtained from the geosynthetic manufacturer.

Once performance tests have been carried out for the design, the specifications of approved geosynthetic products can be described. The words “or equal” and “or equivalent” should be avoided in specifications, unless the equivalence is defined in terms of the index properties and performance criteria required for inclusion in the approved list. An approved product list can also be developed based on experience with commonly encountered conditions.

Once a product list has been approved and established, new geosynthetic products can be added to the specification when they have been approved. Product samples from the manufacturer should be obtained periodically so they can be compared with the original test specimens, to make sure the manufacturing process has not changed since the product was approved. Creating an approved geosynthetic product list takes a lot of effort, but once established, it can be a simple way to identify geosynthetics.