PRS geocell made from unique Neoloy polymeric alloys is the only high-modulus geocell available that was specifically designed for very heavy road reinforcement and ground stabilization. Neoloy-based PRS-Neoloy geocells have a higher tensile stiffness and strength and are more durable over time and under elevated temperatures than conventional geocells, typically made from HDPE.
From HDPE to Neoloy Geocells
While HDPE geocells are typically used for soil erosion control for slope and channel protection, as well as low earth retention structures, their use in ground improvement applications is often limited to low volume roads and temporary pavement structures, due to concerns about stiffness and durability. Dr. DovLeshchinsky in ground-breaking research of geocell reinforcement of retaining walls used HDPE geocells which were sufficient for short-term performance and testing
“However, without improvement, HDPE geocells are not suitable for long-term applications. Problems of durability related to leaching of additives, oxidation, and to UV exposed facing should be addressed. Large thermal contraction and expansion of outer cells due to daily and seasonal temperature changes combined with the high intrinsic thermal coefficient of the geocell material could lead to progressive failure initiating at the outer cells. Stress cracking of exposed facing could occur at low temperature. Low stiffness and strength may lead to significant creep having poor long-term dimensional stability.” Leshchinsky 2009, “Research and innovation”, Geosynthetics Magazine, 27 (4).
Recent research has broadened our understanding of cellular confinement systems and the influencing factors of the reinforcement. The research demonstrates that not all geocells are equal. PRS-Neoloy geocells with a higher elastic modulus produced greater improvement in terms of stiffness, bearing capacity, stress distribution and reduced deformation when compared with conventional HDPE geocells.
Neoloy Polymeric Alloy
PRS identified the need for a new type of geocell that was specifically designed for ground reinforcement HDPE geocells lacked the stiffness and durability required by such long-term applications. PRS embarked on an extensive PRS multi-year R&D program to develop a material that had the flexibility of HDPE but with the elastic behavior (high-modulus) of engineering thermoplastics. The goal was to optimize engineering strength without brittleness in order to enable ease of use.
The result of this program is PRS Neoloy®, a nano-composite alloy of polyester/polyamide nano-fibers dispersed in a polyethylene matrix. Neoloy-based PRS-Neoloy is manufactured in a patented process in multi-layer geocell strips: Two high durability outer layers with a high strength inner core layer for optimal performance: high heat resistance, mechanical strength, rigidity, and chemical stability.
- Neoloy is a very high tensile strength
- Unlike HDPE it has unique predictable, long-term performance –
- Durable under heavy static and dynamic loading
- Dimensional stability in thermal cycling
- Effective service range from-40°Cto +60°C
- Very strong polymeric alloy – suitable for use in base layer of asphalt pavements
- High creep resistance enables long-term design life
- Lower vertical stresses increase subgrade strength – leads to substantial reduction in structural layers
- Specifications based on 3D performance parameters, not polymer or strip characteristics
- Outperforms any other HDPE geocell or geosynthetic (see Comparison)
- Stronger PRS-Neoloy material enables the use of marginal infill and/or a reduction in the layer thickness – resulting in lower infill costs for every project.
- Increased pavement lifespan decreases project lifecycle costs
- High strength material enables more cost-effective geocell configurations
- Increase pavement lifespan– long-term savings
- Lower construction costs – initial savings