ISO/TC 221/WG 5 - Durability

This document provides guidelines for the determination of the long-term strength of geosynthetics for soil reinforcement. This document describes a method of deriving reduction factors for geosynthetic soil-reinforcement materials to account for creep and creep rupture, installation damage and weathering, and chemical and biological degradation. It is intended to provide a link between the test data and the codes for construction with reinforced soil. The geosynthetics covered in this document include those whose primary purpose is reinforcement, such as geogrids, woven geotextiles and strips, where the reinforcing component is made from polyester (polyethylene terephthalate), polypropylene, high density polyethylene, polyvinyl alcohol, aramids and polyamides 6 and 6,6. This document does not cover the strength of joints or welds between geosynthetics, nor whether these might be more or less durable than the basic material. Nor does it apply to geomembranes, for example, in landfills. It does not cover the effects of dynamic loading. It does not consider any change in mechanical properties due to soil temperatures below 0 °C, nor the effect of frozen soil. The document does not cover uncertainty in the design of the reinforced soil structure, nor the human or economic consequences of failure.

This document provides guidelines for the assessment of the durability of geosynthetics, the object of which is to provide the design engineer with the necessary information, generally defined as changes in material properties or as partial safety factors, to ensure that the expected design life of a geosynthetic can be achieved with confidence. This document is not applicable to products designed to survive for only a limited time, such as erosion-control fabric based on natural fibres. This document is applicable to the durability of the geosynthetics and not to the durability of the geotechnical structure as a whole. NOTE The calculation of reduction factors for soil reinforcement applications is described in ISO/TR 20432.

This document specifies methods for screening the resistance of geotextile and geotextile-related products to liquids while not subjecting them to external mechanical stress. It is applicable to all geotextiles and geotextile-related products. Method A applies particularly to polyamides and method B to polyesters and polyamides. The test results are intended to be interpreted in the context of site conditions. This document is intended to be used in conjunction with ISO/TS 13434. NOTE This document only considers conditions where the specimens are fully immersed in the liquids. Though outside the scope of this document, the test conditions can be modified to accommodate particular applications, e.g. gaseous media. This document does not preclude use for test specimens that are pre-treated by some method, e.g. by weathering, aqueous extraction conditions or installation damage.

This document specifies a screening test method for determining the resistance of geotextiles and geotextile-related products to oxidation. The test is applicable to products as follows: — Method A for material consisting solely in polypropylene (PP), polyethylene (PE), polyamide (PA), aramide (AR); — Method B for material consisting solely in polyvinyl alcohol (PVAL). The data are suitable for screening purposes but not for deriving performance data such as lifetime, unless supported by further evidence.

ISO/TS 13434:2008 provides guidelines for the assessment of the durability of geosynthetics, the object of which is to provide the design engineer with the necessary information, generally defined as changes in material properties or as partial safety factors, to ensure that the expected design life of a geosynthetic can be achieved with confidence. ISO/TS 13434:2008 is not applicable to products designed to survive for only a limited time, such as erosion-control fabric based on natural fibres, or geotextiles for asphalt reinforcement. ISO/TS 13434:2008 is applicable to the durability of the geosynthetics and not to the durability of the geotechnical structure as a whole.

ISO/TR 20432:2007 provides guidelines for the determination of the long-term strength of geosynthetics for soil reinforcement. ISO/TR 20432:2007 describes a method of deriving reduction factors for geosynthetic soil reinforcement materials to account for creep and creep rupture, installation damage and weathering, and chemical and biological degradation. It is intended to provide a link between the test data and the codes for construction with reinforced soil.