What is the difference between Grab Tensile ASTM 4632 and Wide Width Tensile ASTM 4595?
Grab Tensile determines the load at which a geotextile breaks. During this test, the end of the sample is not fully clamped. Since the force is not applied to the whole sample, the result is reported only as “pounds of force.” As such, it is not a reliable test for geotextile strength in a woven reinforcement design. Wide Width Tensile requires the entire width of the sample be clamped. As such, this is a true tensile test and reported as “pounds per inch.” For critical applications, Wide Width Tensile is the method engineers use to calculate the required tensile strength of a woven reinforcement geotextile.
Why is Wide Width Tensile ASTM 4595 also reported at different percentages?
You will often see ASTM 4595 specified in terms of % strain (elongation). 1%, 2%, 5% & 10% are typical. Generally speaking, woven fabrics must elongate 4% to 5% before they engage their full tensile strength. Since fabrics are not fully stretched when they are first installed, if the subgrade softens after construction, the fabric will elongate to match. Soils will typically fail at 1-2% elongation, so in critical applications it is important to know at what strain the geotextile will fail.
Can you recommend a woven fabric for a bridge abutment?
Designers have had excellent experience with our US 4800 style products in bridge abutment applications. Obviously all applications and site conditions are unique. But US 4800 style products may be the right product. Visit the 'LINKS' tab to read about the use of US 4800 in the “The GRS Bridges of Defiance County.
How long will this geotextile last?
This geotextile is made from 100% polypropylene. Polypropylene is inert to just about everything on earth and resists biological deterioration, rotting, naturally encountered basics and acids. Polypropylene is stable within a pH range of 2 to 13. The biggest threats to this product are sunlight/ultraviolet radiation (UV), abrasion and soil pH outside 2 to 13. Sufficient cover material will solve the UV and abrasion issue. Studies of PP geotextiles have demonstrated that in stable soils and when sufficiently covered you can expect in excess of 25 years of service life.
Are your woven reinforcement geotextiles NTPEP compliant?
Yes. You will find the NTPEP GTX numbers on the data sheets for those woven reinforcement geotextiles that have been approved by NTPEP.