Geocells Comparision with Geogrids
January 7, 2018
geocell reinforcement sustainabilty

Geocells

Neoloy Geocells are cellular confinement systems for soils stabilization and road reinforcement applications. Neoloy Geocell confinement retains soil, strengthens structures and enhances drainage.  The result an ideal sustainable solution for earth stabilization and ground reinforcement of all types of infrastructure, civil works and landscape architect projects:

  • Load support – highways, unpaved gravel roads, railways, container yards, ports, platforms
  • Slope & channel protection – erosion control, slopes, berms, revetments, banks, channels
  • Earth retention – gravity and reinforced retaining walls and earth stabilization
  • Reservoirs & landfills – geomembrane protection for liquids and waste containment

Neoloy Geocells stabilize road subgrade, reinforces the base and reduces degradation of the surface layer. Neoloy Geocells are an example of an innovative technology that improves road and rail construction, makes roads more sustainable and reduces costs – particularly in problematic soils, difficult locations and where aggregate resources are limited.

The Neoloy Advantage

The material strength and creep resistance of a geocell are key factors to its performance during the lifespan of a project. Creep, or permanent deformation under stress and over time can change the geometry (volume) of a cell. This results in a loss of confinement, increase in settlement and a decrease in compaction, which impacts performance and may invalidate the original design.

Neoloy Geocells are the only geocell made from Neoloy®, a novel polymeric alloy (NPA), developed by PRS. Neoloy offers high elastic modulus, creep resistance and tensile stress for high performance and long-lifespan geocells, especially when compared to other geocells made from HDPE.

Based on an extensive R&D program, worldwide testing by leaders in civil engineering, over 55 published academic articles and validated in thousands of projects worldwide, Neoloy Geocells are the only qualified geocell today, which guarantees pavement performance for the project lifespan.

Engineering benefits include:

  • Very high strength & stiffness
  • Increase pavement layer modulus by ~2.7x
  • Creates beam effect to ‘float’ over problematic soils
  • Qualified, proven results
  • 75 year guaranteed performance

The Neoloy engineering factors substantiate their use in heavy duty applications such as highways, railways and working platforms. Pavement thickness can be reduced and pavement life extended – all while using inferior materials for structural infill.

Neoloy Geocells’ increased pavement performance enables all-weather, durable use and an extended service life. This reduces repairs, increases maintenance cycles and saves maintenance budgets. Roads and rails constructed with Neoloy Geocells are more sustainable and economic with a lower total life-cycle cost.

Main Benefits of Neoloy Geocells:

  • Proven in 1000’s installations, field tests and in 50+ published papers.
  • Outperforms any HPDE based geocell, geogrid or other 2D geosynthetic.
  • Value engineering – reduce pavement thickness and extend lifespan using marginal infill
  • Optimized performance vs. cost – customized geocells according to project requirements.
  • Neoloy alloy inside – engineered for heavy-duty, long-term performance.
  • Sustainable – green solution lowers environmental impact and saves resources.
  • Cost-effective – for both project construction and life-cycle costs.

Cost Comparison with other Solutions

The value of Neoloy Geocells solution is directly related to the project conditions – the more geotechnical challenges there are, the more valuable Neoloy Geocells are, compared to conventional solutions.

Cost-benefit analyses treat the Neoloy Geocells reinforcement as a solution vs. alternative unreinforced solutions and consider all the capital construction costs as well as the long-term life-cycle maintenance costs.

These solution costs include the cost of installation for the Neoloy Geocells vs the savings in labor, earthworks, pavement thickness reduction, use of marginal soils for structural infill, performance improvement (traffic levels and loads), longer environmental impact, lifespan and life-cycle cost reduction in repairs and maintenance.

Cost-Benefit

In general, the more demanding the project requirements, soil conditions, climate and aggregate availability, the more value there is in Neoloy Geocells.

In the installation phase, the sections are folded for cost-effective delivery and can be handled manually on-site without mechanical equipment. Subgrade soil replacement is eliminated or minimized. Aggregate processing and hauling costs are reduced by 50% or more, as Neoloy Geocell reinforcement reduces the layer thickness and allows the use of less expensive locally available lower grade soils for infill.  This also reduces the costs of placement and compaction resulting in additional savings in earthwork equipment, manpower and construction schedules. All-weather installation prevents construction delays.

The increased pavement performance and confinement of aggregates enables more durable use and an extended service life of the road. This reduces repairs, increases maintenance cycles and saves maintenance budgets. Fewer traffic disruptions provide more efficient transportation and allow for growth in traffic and loading. This makes roads constructed with Neoloy Geocells more sustainable economically and with a lower total life cycle cost.

Neoloy Geocells – unlike others – are manufactured in several different types / strengths by application. Each solution is designed and calculated for each project to optimize the cost and performance, including the required design life.

Neoloy Geocells Compared to HDPE Geocells

Geocells manufactured from HDPE have low tensile strength and high creep. This renders HDPE geocells unsuitable for long term applications, particularly when subject to heavy duty cyclical loading or used in extremely low or elevated temperatures.

Neoloy Geocells however – based on Neoloy® novel polymeric alloys (NPA) – maintain their confinement over time, under heavy loading and under high temperatures, due to their very high creep resistance. Neoloy Geocells have demonstrated greater improvement in stiffness, bearing capacity, stress distribution and reduced permanent deformation (creep), when compared with conventional HDPE geocells.

SIM Test showing failure of HDPE GEocell (left) vs negligble deformation of NEOLOY geocell (right) under accelerated loading of 6.1 kn/m

Category Types

PRS Neoloy Geocells – unlike other geocells – are manufactured in 4 categories (A-D) according to application profiles/project requirements:

  1. Cost Effective – erosion control applications
  2. Qualified – channels, walls, subgrades
  3. Tough Cells – road base reinforcement
  4. Heavy Duty – airports, railways, ports, platforms

The category is selected after calculating the typical use, loads, soils, environmental conditions, etc., of a project / design are calculated in order. This enables PRS to match the geocell type with the requirements of the project to optimize cost vs. performance.

Proven Performance

The ability of Neoloy Geocells to maintain their engineering properties without permanent deformation over time has been confirmed by numerous plate-load tests, numerical modeling and full-scale trafficking tests and validated in over 55 published papers. The high modulus, creep resistance and tensile strength of Neoloy make it the most suitable geocell for long-term use in heavy-duty motorways, railways and earth retention applications.


 

Advantages of Neoloy Geocells over HDPE geocells:

  • Longer-term lifespan – 10x more creep resistance (permanent deformation)
  • Higher strength – much higher tensile strength – 24 kn/m and higher
  • Higher elastic modulus – 2-5x higher dimensionally stable under loading
  • Higher-stiffness – adds stiffness to soil infill, layer, pavement
  • Higher environmental durability – 3-5x more resistant to oxidation and UV degradation
  • All-weather use – much higher effective service range: -60°c to +60°c