Geotextile testing per AASHTO M 288 for separation, filtration, stabilization, and drainage applications. Required tests: grab tensile strength (AASHTO T 190), puncture resistance, permittivity, AOS (apparent opening size). Geogrid testing: tensile strength at 2% and 5% strain per GRI-GG1. WSDOT uses the Qualified Products List for approved geosynthetic products. Field installation per manufacturer specifications with minimum overlap of 12 inches for separation applications.
All work under this section shall comply with WSDOT current standards and applicable AASHTO, ASTM, and federal requirements. The Engineer has authority to accept or reject materials and workmanship that do not conform to the specifications.
Source: WSDOT Materials Testing Manual, 2024 Edition. Pages 23–24 of 25.