Multi-axial integral geogrid and methods of making and using same
A monolayer multi-axial integral geogrid suitable for stabilizing aggregate includes a plurality of interconnected oriented strands and partially oriented junctions forming a repeating pattern of outer hexagons having an array of openings therein. Oriented ribs extending inwardly from each of said outer hexagons support and surround a smaller inner hexagon having oriented strands thus forming a plurality of trapezoidal openings and a single hexagonal opening. The oriented strands and partially oriented junctions of the outer hexagons form a plurality of linear strong axis strands that extend continuously throughout the entirety of the geogrid and form additional triangular openings. The geogrid thus includes three different repeating geometric shapes. The inner hexagons preferably also can move up and down, out of the plane of the geogrid. The multi-axial integral geogrid thus provides a geometry that can better engage with, confine and stabilize a greater variety and quality of aggregates.
1 . A starting material for making a multi-axial integral geogrid comprising a polymer sheet having a pattern of holes or depressions therein that provide three different shaped openings and a plurality of strands separated from each other by about 120° that extend linearly and continuously throughout an entirety of the multi-axial geogrid when the sheet is biaxially stretched.
2 . The starting material according to claim 1 , wherein the pattern of holes or depressions provides a repeating hexagon formed of oriented strands within a hexagon pattern of openings when the sheet is biaxially stretched.
3 . The starting material according to claim 1 , wherein the three different shaped openings are repeating hexagonal, trapezoidal and triangular shapes.
4 . The starting material according to claim 1 , wherein the polymer sheet has an initial thickness of from about 3 mm to about 10 mm.