Enhancing Road Infrastructure in Zirakpur, Punjab with PP Biaxial Geogrid – 30 kN

On a road infrastructure project in Zirakpur, Punjab, Ocean Non Wovens supplied and installed 2,863 square metres of Ocean PP Biaxial Geogrid – 30 kN. The geogrid went on the prepared subgrade under the aggregate base to stabilise the subgrade, spread wheel loads and reduce rutting and surface distress under heavy traffic.

Project overview

• Project Type: Road Infrastructure Reinforcement
• Location: Zirakpur, Punjab
• Product Supplied: Ocean PP Biaxial Geogrid – 30 kN
• Quantity Used: 2,863 SQM
• Objective: To stabilise the subgrade and extend the life of the road pavement under heavy traffic loads.

The problem: subgrade failure and rutting

Subgrade failure and rutting are two of the most common reasons a flexible pavement wears out early. The usual causes are:

• Weak subgrade soil
• A high water table that softens the subgrade
• Heavy traffic loads, especially from commercial vehicles

Under each wheel pass, unconfined aggregate in the base spreads sideways and the subgrade below deforms. Over thousands of passes, that shows up as ruts and cracks at the surface.

How a biaxial geogrid helps

A biaxial geogrid is a polymer grid with similar strength in both directions. When aggregate is compacted onto it, the stone partly enters the apertures and locks against the ribs. The grid then restrains the aggregate from moving sideways, keeping the base stiffer and spreading the load over a wider area of subgrade. This is the lateral restraint mechanism, and it is why junction strength and rib stiffness matter as much as ultimate tensile strength.

In India, the use of geogrids in road pavements is covered by IRC SP:59 (Guidelines for Use of Geosynthetics in Road Pavements and Associated Works). The benefit is usually expressed as a reduction in base course thickness or an increase in the traffic a section can carry, and the figures used in design should come from test data for the specific product.

Ocean PP Biaxial Geogrid – 30 kN

The polypropylene (PP) Biaxial Geogrid – 30 kN is made for soil reinforcement and base stabilisation. It offers:

• Tensile strength in both the longitudinal and transverse directions
• Strong junctions to transfer load between ribs
• Resistance to biological and chemical degradation
• UV stabilisation for the period it is exposed during construction

The 30 kN strength class suits roads carrying moderate to heavy traffic, such as those in semi-urban areas like Zirakpur.

Typical technical data (Ocean):

• Aperture Size: 30 mm x 30 mm
• Tensile Strength at 2% Strain: ~8 kN/m
• Tensile Strength at 5% Strain: ~15 kN/m
• Ultimate Tensile Strength: ≥30 kN/m

Geogrid tensile properties, including strength at 2% and 5% strain, are measured by ASTM D6637 (or ISO 10319). The low-strain values are the ones that reflect how the grid behaves under traffic, since a pavement never strains anywhere near the ultimate value.

Installation

1. Subgrade preparation: The native soil was cleaned, graded and compacted.
2. Geogrid placement: The geogrid was laid directly on the prepared subgrade, with overlaps as per IRC guidelines.
3. Aggregate laying: Well-graded aggregate was placed over the geogrid, spread forward from the covered area so that vehicles did not run on the bare grid.
4. Compaction: Vibratory rollers compacted the aggregate to lock it into the geogrid apertures.

Good interlock between aggregate and geogrid is what prevents lateral movement, spreads the load and reduces subgrade deformation. The aggregate needs a gradation that can enter the apertures, and the grid should lie flat and taut so it engages as soon as load is applied.

Benefits beyond the pavement

• Less material: Where design allows a thinner base, less aggregate is quarried, hauled and compacted.
• Lower maintenance: A stabilised base ruts less, so the pavement needs fewer repairs over its life.
• Design support: Ocean Non Wovens provides in-house technical support so the geogrid is placed at the right level and specified correctly in the pavement design.

For road, rail or other infrastructure projects, contact Ocean Non Wovens to discuss geogrid grades for your pavement design, or see more road case studies and other geosynthetics.