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发布日期:2021年12月06日

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Geotextiles
Introduction:

According to the historical record, it is believed that the first applications of geotextiles were woven industrial fabrics used in 1950’s. One of the earliest documented cases was a waterfront structure built in Florida in 1958. Then, the first nonwoven geotextile was developed in 1968 by the Rhone Poulence company in France. It was comparatively thick needle-punched polyester, which was used in dam construction in France during 1970.
As we know, the prefix of geotextile, geo, means earth and the ‘textile’ means fabric. Therefore, according to the definition of ASTM 4439, the geotextile is defined as follows:
"A permeable geosynthetic comprised solely of textiles. Geotextiles are used with foundation, soil, rock, earth, or any other geotechnical engineering-related material as an integral part of human-made project, structure, or system."
The ASAE (Society for Engineering in Agricultural, Food, and Biological Systems) defines a geotextile as a "fabric or synthetic material placed between the soil and a pipe, gabion, or retaining wall: to enhance water movement and retard soil movement, and as a blanket to add reinforcement and separation." A geotextile should consist of a stable network that retains its relative structure during handling, placement, and long-term service. Other terms that are used by the industry for similar materials and applications are geotextile cloth, agricultural fabric, and geosynthetic.

Basic Test:

Tensile test: A sample is clamped between two jaws and strained at a constant rate until failure. Maximum load and extension are recorded.
CRB Puncture Resistance: A sample is clamped in a ring and a 50mm diameter plunger is pushed against the centre of the sample extending it until failure. Maximum load and plunger displacement are recorded.
Cone Drop Perforation: A sample is clamped in a ring and a 45" cone allowed to free fall half a metre on to it. The diameter of any resulting perforation is measured.