BS 8661:2019 pdf download

BS 8661:2019 pdf download.Geotextiles – Guidance for specification for basic separation and filtration functions
1 Scope
This British Standard gives recommendations and guidance for the choice and specification of geotextiles for the functions of separation and filtration in contact with natural soils and fills. This British Standard provides information for various applications and service lives.
This British Standard is not applicable to geocomposite geosynthetic products which incorporate a geotextile component covered by this standard.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes provisions of this document.1 For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
BS EN ISO 9862, Geosynthetics一Sampling and preparation of test specimens
BS EN ISO 10318-1, Geosynthetics – Part 1: Terms and definitions
BS EN ISO 10318-2, Geosynthetics – – Part 2: Symbols and pictograms
BS EN ISO 10319, Geosynthetics – Wide-width tensile test
BS EN ISO 12236, Geosynthetics一Static puncture test (CBR test)
4.3 Mechanical recommendations for separation
The recommended property values for the specification profiles (1 to 3) shown in Table 3 are given in:
a] Table 4 for high-extension geotextiles (typically non-woven); and
b] Table 5 for low-extension geotextiles (typically woven).
The recommended property values quoted in Table 4 and Table 5 take into account any declared tolerance as detailed on the CE Declaration of Performance (DoP]. Products without a declared tolerance should not be accepted. It should be noted that manufacturers’ product data sheets are not DoPs and are not considered adequate for the above purposes.
Manufacturers’ DoPs are prepared to ensure conformity to the following EN harmonized European standard(s) as appropriate:
1) BS EN 13249, Geotextiles and geotextile-related products – Characteristics required for use in the construction of roads and other trafficked areas (excluding railways and asphalt inclusion)
2] BS EN 13250, Geotextiles and geotextile-related products – Characteristics required for use in the construction of railways
3) BS EN 13251, Geotextiles and geotextile-related products – Characteristics required for use in earthworks, foundations and retaining structures
4) BS EN 13252, Geotextiles and geotextile-related products – Characteristics required for use in drainage systems
5) BS EN 13253, Geotextiles and geotextile-related products – Characteristics required for use in erosion control works (coastal protection, bank revetments)
6] BS EN 13254, Geotextiles and geotextile-related products – Characteristics required for the use in the construction of reservoirs and dams
7] BS EN 13255, Geotextiles and geotextile-related products – Characteristics required for use in the construction of canals
4.4 Hydraulic recommendations for separation with insignificant filtration
If the geotextile is required mainly for separation and the filtration requirements are insignificant then the properties in Table 6 should be satisfied.