ISO/TC 221 - Geosynthetics

This document considers the guidance for geotechnical and civil engineers involved in the design of the barrier function.

This document outlines the criteria for evaluating the available and the required flow rate of geosynthetics in various situations, provides a summary of the available laboratory testing, and lists the safety factors and reduction factors that can be applied to the parameters when designing using geosynthetics for drainage systems.

This document provides general considerations to support the design guidance to geotechnical and civil engineers involved in the design of structures in which a geotextile is used to fulfil the function of separation of soils and below ground structures in contact with natural soils and fills. These considerations are always based on installed soils, the installation process and on the strength and/or deformation behaviour of geosynthetics.

This document provides general considerations to support the design guidance to geotechnical and civil engineers involved in the design of structures in which a geotextile is used as reinforcement. The key potential failure mechanisms are described, and guidance is proposed to select engineering properties.

This document provides general considerations to support the design guidance to geotechnical and civil engineers involved in the design of structures in which a geotextile is used as a filter. The key potential failure mechanisms are described, and guidance is proposed to select engineering properties.

This document specifies index test methods for determining the compressive creep properties of geosynthetic products. The test specimens are subjected either to normal compressive loading or to a combination of normal compressive loading and shear loading. The test method with a normal load only (see Clause 5) is the standard method. The test method in which combined normal and shear loads are applied (see Clause 6) is intended for products that are sensitive to shear failure, i.e. which have a columnar or cuspated structure. The tests are carried out on dry specimens or on specimens immersed in water. The test is intended to be carried out with the specimen immersed in water when any part of the geosynthetic product contains a hydrophilic polymer.

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 a method for determining the constant-head water flow capacity within the plane of a geotextile or geotextile-related product, using boundary materials and test conditions of interest. A standard series of test conditions are proposed, involving soil confinement, low hydraulic gradients, seating times and an array of normal loads.

This document specifies a method for determining the constant-head water flow capacity within the plane of a geotextile or geotextile-related product. This document describes the in-plane water flow index test, only applicable to factory-assembled products. For the in-plane water flow performance test, see ISO 12958-2.

This document specifies a test method for determining the abrasion resistance of geotextiles and geotextile-related products under wet conditions. This document is applicable to geotextiles and geotextile-related products intended to be used as e.g. geo bags or filter beneath armourstone. The test method simulates abrasion impacts on geotextiles and geotextile-related products such as that caused by the movement of rocks in an embankment or transport of sediment in rivers. This document provides an index test which can be used for performance and acceptance testing. It can be used as performance test by comparison of mechanical and/or additional hydraulic properties before and after abrasion impact.

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 provides general considerations to support the guidance to geotechnical and civil engineers for design using geosynthetics provided in the subsequent parts of the ISO/TR 18228 series.

This document specifies a method for the determination of the characteristic size of the openings of a single layer of a geotextile or geotextile-related product using the wet-sieving principle.

This document describes index test methods for the determination of the strength of internal structural junctions of geocells under different loading conditions.

This document describes an index test procedure for simulating mechanical damage to geosynthetics, caused by granular material, under repeated loading. The damage is assessed visually and by the loss of tensile strength. Other reference tests can be used to assess the damage caused by this test. The test method described is an index test procedure, using a standard granular material, and is not intended to be used for the derivation of a reduction factor for geosynthetic reinforcement.

This document specifies a method for the on-site installation and retrieval of geosynthetic samples, irrespective of the particular degradation mechanisms to which they are exposed. The method is also appropriate to test for mechanical damage, much of which occurs during installation, and to provide an owner with information about the state of the geosynthetic product in their structure.

This document specifies two test methods for determining the water permeability characteristics of a single layer of geotextile or geotextile-related product normal to the plane: a) the constant head method; and b) the falling head method.

This document specifies the information accompanying geosynthetics to enable the user on site to identify the goods as being identical to the goods ordered. The positive identification, e.g. of unwrapped or rolled-out geosynthetics, is an important aim of this document. The information specified does not replace a technical data sheet and cannot be used to verify the conformance of the product with the technical requirements.

This document specifies an index test method to determine the friction characteristics of geosynthetics in contact with a standard sand as described in EN 196-1, i.e. with a specified density and moisture content, under a normal stress and at a constant rate of displacement, using a direct shear apparatus. The same testing procedure can be used with any type of soil with the density and moisture content that are required to evaluate the performance under specific conditions or with another geosynthetic under a normal stress and at a constant rate of displacement, using a direct shear apparatus. The procedure can also be used for testing geosynthetic barriers.

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 9863-1:2016 specifies a method for the determination of the thickness of geosynthetics at specified pressures and specified load plate areas or under specified point loads. It defines the pressures or the load at which the thickness is determined. The test results are intended for identification purposes and for use in technical data sheets and/or as part of other test methods, e.g. tests of hydraulic properties. The method is applicable to all geosynthetics.

ISO 18325:2015 specifies a test method for determining the water discharge capacity of prefabricated vertical drains (PVDs), which can be used for conformance and acceptance testing. This is an index test.

ISO 25619-2:2015 specifies an index test method for determining the short-term compressive behaviour of geosynthetics. It can be used to determine the deformation behaviour under short-term compressive stress, e.g. after exposure to stress, liquids, or light. ISO 25619-2. 2015 can be used for quality control purposes. It is not intended to be used for design purposes.

ISO 10319:2015 describes an index test method for the determination of the tensile properties of geosynthetics (polymeric, glass, and metallic), using a wide-width strip. It is applicable to most geosynthetics, including woven geotextiles, nonwoven geotextiles, geocomposites, knitted geotextiles, geonets, geomats, and metallic products. It is also applicable to geogrids and similar open-structure geotextiles, but specimen dimensions might need to be altered. It is not applicable to polymeric or bituminous geosynthetic barriers, while it is applicable to clay geosynthetic barriers. ISO 10319:2015 specifies a tensile test method that covers the measurement of load elongation characteristics and includes procedures for the calculation of secant stiffness, maximum load per unit width and strain at maximum load. Singular points on the load-extension curve are also indicated. Procedures for measuring the tensile properties of both conditioned and wet specimens are included in ISO 10319:2015.

The intent of ISO 10318-2:2015 is to define property symbols, graphical symbols, and pictograms used in EN and ISO geosynthetics standards. Definitions of particular or specific symbols and pictograms terms not included in this this part of ISO 10318 can be found in the International Standards describing appropriate test methods.

ISO 13427:2014 specifies a test method used for the determination of the resistance of geosynthetics to abrasion using a sliding block, whereby after abrasion the loss in tensile properties is determined. This test method is applicable to all geosynthetics used in the construction of railways.

ISO 10776:2012 describes a method for determining the water permeability characteristics of geotextiles or geotextile-related products normal to the plane when subjected to specific normal compressive loads.

ISO 10772:2012 describes a test method for determining the soil passing through a geotextile filter when exposed to turbulent external water flow conditions.

ISO 10769:2011 specifies a method for determining the water absorption of bentonite. The bentonite component is a part of clay geosynthetic barriers (GBR-C). Water absorption depends on the specific surface of the fine particles and the surface activity of the bentonite. The test provides an index value for production control testing of GBR-C.

ISO 10773:2011 specifies a method for measuring gas flow through a clay geosynthetic barrier. As clay geosynthetic barriers are used to contain gases in long-term applications, this test especially focuses on the steady state of the phenomenon.

ISO 10321:2008 specifies an index test method for determination of the tensile properties of joints and seams in geosynthetics, using a wide-width strip. The method is applicable to most geosynthetics. It is also applicable to geogrids, but the specimen dimensions may need to be altered. This test is not applicable to polymeric or bituminous geosynthetic barriers. The method specified in ISO 10321:2008 quantifies the tensile strength of a joint or seam between geosynthetics. It can provide data to indicate the joint or seam tensile strength which can be achieved. Procedures for measuring the tensile properties of both conditioned and wet specimens are included.

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.

ISO/TS 19708:2007 specifies a test method for the determination, using a roller compactor for bituminous mixtures, of the damage to a geosynthetic used as a separator in interlocking-concrete-block pavements. The geosynthetic is placed between a cushion-sand course and a base coarse material. The roller compactor simulates highway traffic load and pedestrian load. After the roller compactor test, the cushion sand retained is determined. ISO/TS 19708:2007 can be used for selecting a geosynthetic.

ISO 12236:2006 specifies a method for the determination of the puncture resistance by measuring the force required to push a flat-ended plunger through geosynthetics. The test is normally carried out on dry specimens conditioned in the specified atmosphere. The test is applicable to most types of products, but not to materials with apertures greater than 10 mm.

ISO 13433:2006 specifies a method to determine the resistance of geosynthetics to penetration by a steel cone dropped from a fixed height. The degree of penetration is an indication of the behaviour of the geosynthetic when sharp stones are dropped on its surface. The method is generally applicable to geosynthetics. However, the validity of this test for some types of products should be considered carefully, as the test principle may not be applicable.

ISO 13426-2:2005 describes index tests for determining the strength of the internal structural junctions of all geocomposites and of clay geosynthetic barriers.

ISO 9862:2005 establishes general principles for the sampling of geosynthetics delivered to construction sites, and for the preparation of test specimens from the samples. The sampling principles are applicable to geosynthetics supplied in rolls. The specimen-preparation principles are applicable to all geosynthetics.

ISO 13428:2005 describes an index test for the determination of the protection efficiency of a geosynthetic on a hard surface, exposed to the impact load of a hemispherical object. The index test measures the change in thickness of a thin lead plate lying between the geosynthetic and a rigid support.

ISO 12957-2:2005 describes a method of determining the friction characteristics of geosynthetics (geotextiles and geotextile-related products, geosynthetic barriers), in contact with soils, at low normal stress, using an inclining plane apparatus. This method is primarily intended as a performance test to be used with site-specific soils but may also be used as an index test with standard sand. Test data obtained for geogrids tested with a rigid support are not necessarily realistic as the results depend on the friction support.

ISO 9864:2005 specifies a method for the determination of mass per unit area of geotextiles and geotextile-related products for identification purposes and for use in technical data sheets. The method is applicable to all geotextiles and geotextile-related products.

ISO 12958:2010 specifies a method for determining the constant-head water flow capacity within the plane of a geotextile or geotextile-related product.

ISO:12956:2010 specifies a method for the determination of the characteristic size of the openings of a single layer of a geotextile or geotextile-related product using the wet-sieving principle.

ISO 11058:2010 specifies two test methods for determining the water permeability characteristics of a single layer of geotextile or geotextile-related product normal to the plane: - the constant head method; - the falling head method.

ISO 25619-2:2008 specifies an index test method for determining the short-term compressive behaviour of geosynthetics. It can be used to determine the deformation behaviour under short-term compressive stress, e.g. after exposure to stress, liquids or light. ISO 25619-2:2008 can be used for quality control purposes. It is not intended to be used for design purposes.

ISO 25619-1:2008 specifies index test methods for determining the compressive creep properties of geosynthetic products. The test specimens are subjected either to normal compressive loading or to a combination of normal compressive loading and shear loading.

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.