1. Multi-axial tensile testing
a new standard
in geogrid testing.
Utilizing astm d5617 to compare
geogrid performance
Reflective of real-world stresses

2. CURRENT geogrid SPECIFICATIONS
FOR RIB STRENGTH/PROPERTIES:
ASTM D6637
UltIMATE TENSILE STRENGTH
TENSILE STRENGTH AT 2% STRAIN
TENSILE STRENGTH AT 5% STRAIN
FOR GRID JUNCTION STRENGTH/PROPERTIES:
Gri-gg2 –junction strength
Army corp of engineers - Aperture stability
All single plane tests that show:
index values for quality assurance
Comparative values to publish
No relationship to in-use performance of geogrids

3. Astm d5617: multi-axial tensile test
for geosynthetics
Scope:
“…covers the measurement of the out-of-plane response of geosynthetics to a force applied perpendicular to the initial plane of the sample.”
Primarily used in testing of geomembranes

4. Astm d5617: multi-axial tensile test
for geosynthetics
Optimum for geogrid testing because:
Stresses entire grid assembly
Applies short-term, high-intensity load

5. Rectangular vs. triangular aperture?
Why consider Astm d5617?
Best imitates the wheel loading through a compacted base course in a laboratory environment
‘apples to apples’ Performance comparison on geogrid styles
Rectangular vs. triangular aperture?
No rib tensile strength values (Δ)
Aperture stability value: lower torque (Δ)

6. Astm d5617 results and feedback IDEAL FOR PERFORMANCE COMPARISON
4 repeatable, definable test results:
Deflection at rupture
Pressure at rupture
Axi-symmetric break resistance strain
Failure specifics
IDEAL FOR PERFORMANCE COMPARISON

7. Tbx biaxial geogrid vs. triangular aperture grid
RESULTS