Validation & Research

Research & Validation for Ground Stabilization

Neoloy® Tough-Cells are supported by laboratory research, full-scale testing, numerical modeling and field validation. This work defines how NPA properties and cellular confinement contribute to structural performance and PRS design methods.

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Laboratory Material and system behavior
Full Scale Traffic and structural loading
Field Monitoring and quality verification
Research Published and collaborative studies

Testing Neoloy® Performance and Geocell System Behavior

Neoloy® Tough-Cells are evaluated through multiple testing methods to understand material behavior, structural response, field performance and quality control under real engineering conditions.

Traffic Performance Full-Scale Moving-Wheel Testing Repeated wheel loading, rutting and stress distribution. View section Material Behavior Dynamic Mechanical Behavior Stiffness, energy response and behavior under changing conditions. View section Field Verification Static Plate Load Testing In-situ stiffness, deformation and quality-control verification. View section Seismic Research Seismic Performance Large-scale research into flexible confinement under seismic loading. View section
Traffic Performance

Full-Scale Moving-Wheel Testing

Full-scale accelerated pavement testing evaluates how reinforced pavement sections respond to repeated wheel loading under controlled traffic conditions. Published testing compared NPA-reinforced and unreinforced recycled asphalt pavement over weak subgrade, measuring rutting, deformation and load distribution.For the comparable FRAP sections, the same 25 cm total base thickness was used with consistent compaction. The NPA-reinforced sections developed less rutting and sustained more wheel passes before reaching the same rut-depth level.

Key Result • Wheel passes to 75 mm rut depth
1,200
Wheel Passes
Unreinforced FRAP
25 cm Control section
1,600
Wheel Passes
NPA Reinforced
7.5 cm reinforcement
2,200
Wheel Passes
NPA Reinforced
10 cm reinforcement

PUBLISHED TEST FIGURE

Fig. 8 – Rut depth vs. number of wheel passes for FRAP sections.

Evidence source: Han et al. (2011), Performance of Geocell-Reinforced RAP Bases over Weak Subgrade under Full-Scale Moving Wheel Loads. Read more

ACCELERATED PAVEMENT TESTING AT KANSAS STATE UNIVERSITY.

MATERIAL BEHAVIOR

Dynamic Mechanical Behavior

Dynamic Mechanical Analysis (DMA) shows how a material responds to repeated, small oscillating loads as temperature and time change. It measures the relationship between applied stress and the resulting deformation.

The test helps engineers understand three key parts of material behavior: elastic stiffness, energy loss and damping. These properties help show how a polymer behaves under changing service conditions

What DMA measures

E′
Storage Modulus
Shows the material’s elastic stiffness and how much energy is stored during loading.
E″
Loss Modulus
Shows how much energy is dissipated during each loading cycle.
tan δ
Loss Factor
Indicates damping — how much energy is lost compared with the energy stored.
Validation & Research

DMA principle — an oscillating stress is applied and the material’s strain response and phase shift are measured.

Source: Dynamic Mechanical Analysis (DMA), Chapter 6.

Validation & Research

Typical DMA response showing how storage modulus, loss modulus and damping change with temperature.

Source: Dynamic Mechanical Analysis (DMA), Chapter 6.

FIELD VERIFICATION

Static Plate Load Testing & Quality Control

Static plate load testing is used on site to check how a pavement layer responds to load and to compare a Neoloy® Tough-Cells reinforced section with an unreinforced control section. A vertical load is applied through a rigid plate while the resulting surface movement is measured.

The results are used to determine pavement stiffness and the in-situ Modulus Improvement Factor (MIF). Where pressure cells are installed, stresses below the reinforced and control sections can also be compared.

Why it matters

The test provides a practical field check that the constructed layer is performing as intended. Results are reviewed together with compaction, moisture and material-quality data — the plate load result is not used alone to approve the layer.

Validation & Research

Unreinforced control chart
Loading and unloading response of the unreinforced control section during static plate load testing.

Validation & Research

Neoloy® reinforced chart
Loading and unloading response of the Neoloy® Tough-Cells reinforced section during static plate load testing.

Source: Static Plate Load Test Procedures, Rev. 2023.1

Static plate load testing in the field to measure the response of a Neoloy® Tough-Cells reinforced pavement layer.

Seismic Reseach

Geocell Behavior Under Seismic Loading

Large-scale shake-table testing examined how geocell retaining and reinforced slope systems behave during strong earthquake loading. Five test structures were subjected to ground motion based on the 1995 Kobe earthquake and then examined for deformation and the development of slip surfaces.

The tests showed that the flexible systems could deform and dissipate energy while maintaining the overall structure. Under the tested conditions, the study reported upper-bound equivalent seismic coefficients of approximately 0.4 × PGA for gravity-wall configurations and 0.3 × PGA for reinforced geocell systems.

Why it matters

The research helps engineers understand how flexible cellular confinement systems respond under severe seismic loading and how this behavior can be considered in seismic stability analysis.

Validation & Research

Selected Research & Testing

Published studies and field research have examined how NPA-based cellular confinement influences stiffness, deformation, load distribution and long-term infrastructure performance. The studies below represent a selected sample of this research — not the complete body of work.

SELECTED RESEARCH & TESTING

Research Behind the Engineering

Explore six selected studies examining material behavior, structural performance, railway applications, pavement reinforcement and field validation.

6 Selected Studies
120+ Research & Technical References
Browse the selected research
RESEARCH / VALIDATION / FIELD PERFORMANCE
01
Creep & Deformation
2011
Thakur et al. · GeoFrontiers

Creep Deformation of Unreinforced and Geocell-Reinforced Recycled Asphalt Pavements

What was studied

Laboratory testing compared unreinforced RAP with RAP confined by NPA material under sustained loading at 25°C. The study measured initial deformation and how deformation continued to develop over time.

Why it matters

Recycled materials can provide structural value, but their long-term deformation must be controlled. The research showed how cellular confinement can help improve the stability of RAP under sustained load.

Key finding
≈45%
Lower creep rate

NPA confinement significantly reduced both initial deformation and the rate of creep under the tested conditions.

View Research →
02
Design Calibration
2011
Kief et al. · Geosynthetics India

Modulus Improvement Factor for Geocell-Reinforced Bases

What was studied

Laboratory testing, field data and pavement analysis were used to quantify the structural contribution of NPA reinforcement through the Modulus Improvement Factor (MIF).

Why it matters

MIF provides a practical link between measured improvement and pavement design, helping engineers account for the reinforced layer when optimizing pavement structures.

Design example
2.54
Equivalent MIF

The Highway 6 demonstration design used an equivalent MIF of 2.54 for the full reinforced base.

View Research →
03
Railway Modeling
2013
Leshchinsky & Ling · Geotextiles and Geomembranes

Numerical Modeling of Behavior of Railway Ballasted Structure with Geocell Confinement

What was studied

Large-scale laboratory testing using NPA confinement was combined with validated 3D finite-element modeling to study railway ballast under different foundation and ballast conditions.

Why it matters

The research helps explain how confinement limits ballast movement and distributes loads more evenly, particularly where railway foundations are weak or ballast quality is reduced.

Key finding
67%
Lower lateral spreading

In the modeled railway configuration, confinement substantially reduced lateral movement and improved stress distribution.

View Research →
04
Expansive Clay & Rail
2015
Ofer Kief · Geosynthetics 2015

Hybrid Geosynthetic Solution for Rail Track on Expansive Clay

What was studied

The study examined a railway system combining a stiff biaxial geogrid at the subgrade with NPA reinforcement within the granular layer above expansive clay.

Why it matters

Expansive soils can cause uneven movement and recurring track maintenance. The hybrid system was developed to reduce differential heave and improve track stability.

Field outcome
Satisfactory structural performance and rail alignment

Field experience supported continued use of the hybrid solution for problematic expansive-soil conditions.

View Research →
05
Field Validation · Railway
2017
Zarembski et al. · Amtrak Northeast Corridor

Application of Geocell Track Substructure Support System to Correct Surface Degradation Problems Under High-Speed Passenger Railroad Operations

What was studied

An instrumented field study compared reinforced and control sections on Amtrak’s Northeast Corridor under high-speed and regional passenger traffic.

Why it matters

The project moved beyond laboratory testing by measuring pressure and track geometry under operating railway conditions.

Field results
≈50% Lower subgrade pressure
6.7× Longer surfacing cycle
View Research →
06
Sustainable Roads
2016
Pokharel et al. · Resilient Infrastructure

Sustainable Road Construction for Heavy Traffic Using High Strength Polymeric Geocells

What was studied

Four heavy-traffic road projects in Alberta evaluated the use of Neoloy® reinforcement to reduce aggregate demand, haulage and dependence on imported construction materials.

Why it matters

The case studies demonstrate how structural reinforcement can support greater use of local materials while reducing material transport and associated environmental impact.

Case-study results
30–50% Aggregate savings
25–≈60% CO₂ savings*
*Across four case studies, based on aggregate production and material haulage.
View Research →
00 / 06

Industry Recognition & Perspectives

See what engineers, project teams and independent industry publications say about Neoloy® Tough-Cells through real project experience, professional perspectives and media coverage.

UK Royal Engineers Road Infrastructure
75% Less Aggregate ~⅓ lower projected road cost
“The performance of the Route Trident with Neoloy reinforcement exceeded all expectations.”
Lt. Col. M. T. G. Bazeley Commanding Officer · 28 Engineer Regiment
University of Delaware Railway
~7× Maintenance Improvement Reduced surfacing maintenance cycle
“The PRS-Neoloy reinforcement proved to be effective in reducing degradation, showing a reduction in the surfacing maintenance cycle on the order of seven times.”
Allan M. Zarembski, PhD, PE Director · Railroad Engineering & Safety Program · Amtrak Project
Áncora Ingeniería Airport
Only Qualified Solution Exceeded all project requirements
“The PRS-Neoloy was the only qualified solution that not only met, but exceeded, all our project requirements.”
Eng. Mario Iruegas Evaristo CEO · Interjet Apron, Mexico City International Airport
Ludemann Engenharia Airport
~6 m Very Soft Soil Settlement stabilization · No schedule impact
“The initial results indicate a stabilization of the settlements and an adequate distribution of the angular distortions, thanks to the high stiffness of the Neoloy 12 cm height cells.”
Sérgio Murari Ludemann Geotechnical Designer · GRU Airport
UNOPS Roads & Airfield
Fast Delivery to a Remote Project Supply · on-site training · technical support
“Fast delivery. Excellent technical support – on-site training. Responsive and professional service.”
William Muchira Project Manager · EU ZB Project
STRABAG Port Infrastructure
Local Materials Reused Avoided replacement of low-bearing soil
“The Neoloy system made it possible to make a rigid structure resistant to deformations with a high load-bearing modulus.”
Marcin Wróblewski Technical Director · Port of Gdańsk Expansion
INGEO Port Infrastructure
Technical Assistance Geotechnically challenging pavement conditions
“We were satisfied with the technical assistance from PRS Poland and would recommend PRS Neoloy in other geo-technically challenging projects.”
Marcin Blockus, Civ. Eng., PhD CEO · INGEO Sp. z o.o. · Balticon Container Yard
PKP-LHS Heavy-Duty Pavement
Durability & Lower Maintenance Intermodal terminal · weak subgrade · heavy loads
“We are confident that other organizations seeking similar solutions will find PRS Neoloy Tough-Cells an invaluable asset.”
Dariusz Kardasz Director · Infrastructure Department · PKP-Linia Hutnicza Szerokotorowa
National Projects & Construction Railway
Reduced Pavement Structure Local sand · recycled asphalt · third-party testing
“We highly value the cooperation and engineering expertise demonstrated by PRS and we are pleased to recommend the use of Neoloy Tough-Cells in future railway and roads projects.”
Engr. Helmy Nagy Mohamed Chief Executive Officer · MBZ Railway Project
Stratum Logics Engineering Perspective
10+ Years of Design Use Roads · drilling rigs · logyards · working platforms
“From a professional civil engineering point of view I strongly recommend the use of Neoloy for ground improvement and road reinforcement projects.”
Sanat Pokharel, PhD, P.Eng. Principal Engineer · Stratum Logics Inc.
Dr Arno Hefer Consulting Engineering Perspective
Weak & Expansive Soils Railways · roads · airfields · loading platforms
“The NPA solution has proven itself from both economic and engineering perspectives, especially in applications subject to heavy loads.”
Dr. Arno Hefer, PrEng Principal Consultant · Dr Arno Hefer Consulting
USACE · ERDC Research Evaluation
Full-Scale Evaluation Simulated cargo-aircraft traffic · airfield repair research
“The PRS-Neoloy-356-200 product performed well as part of these experiments. The product was purchased directly from the manufacturer and delivered in a timely manner.”
Lyan Garcia, PE Research Civil Engineer · ERDC Airfields & Pavements Branch · USACE
Weetvanwegen Engineering Perspective
Confinement & Stiffness Road bases · railway sub-bases · poor subgrade
“The cell walls of the Neoloy completely encase the infill material and provide an all-around confinement to the soil.”
Christ van Gurp Pavement Engineer · Weetvanwegen
SKANSKA Road Infrastructure
Technical Requirements Met Simple installation · reduced construction cost

Skanska reported that the Neoloy system met the project’s technical requirements, with straightforward installation, reduced road-construction costs and a relatively short installation time.

Jan Jakubowski · Paweł Raszewski Site Manager & Head Process Engineer · SKANSKA S.A.
Request Client References

Industry Coverage

Neoloy® projects, field applications and supporting research have been featured in engineering and infrastructure publications worldwide.

ISSUE 01
WSP Insights
Airfield · South Sudan
2019
INFRASTRUCTURE FIELD
STORY
Alastair Currie
November 4, 2019
FEATURED INDUSTRY COVERAGE

Rehabilitating a Critical Airstrip

WSP’s account of the rehabilitation and extension of the Rubkona gravel runway in South Sudan, including a value-engineered cellular confinement solution using locally sourced sand.

Reported Project Comparison
~$27M → ~$10M

Estimated construction-cost comparison reported in the article.

Read Article
ISSUE 02
IMIESA
Infrastructure · Airfield
2019
MUNICIPAL PROJECT
COVERAGE
October 2019
Page 32
INDUSTRY PUBLICATION

Rubkona Airfield Rehabilitation

Coverage of the Rubkona airfield rehabilitation project in South Sudan in the official magazine of the Institute of Municipal Engineering of Southern Africa.

Project Focus
Airfield rehabilitation in challenging ground conditions

Independent infrastructure coverage of a major rehabilitation project in South Sudan.

View Publication
ISSUE 03
Roads & Bridges
Research · Unpaved Roads
2011
RESEARCH ROAD
TESTING
Jie Han · Sanat K. Pokharel
Xiaoming Yang · Jitendra Thakur
RESEARCH IN THE PRESS

Unpaved Roads: Tough Cell

A University of Kansas research overview covering plate-load, cyclic loading and full-scale moving-wheel testing of NPA-reinforced unpaved road sections.

Testing Covered
Multiple full-scale and laboratory test methods

Stiffness, bearing capacity and permanent deformation were among the performance characteristics examined.

Read Article
ISSUE 04
Revista Vial
Technology · NPA
2019
TECHNOLOGY NPA
SYSTEMS
Diego Skok
July 3, 2019
INTERNATIONAL COVERAGE

Nano-Polymeric Alloy (NPA) Cellular Confinement

An overview of the development of NPA cellular confinement technology, with infrastructure examples including airports, railways and port facilities.

Technology Focus
NPA applications across infrastructure sectors

The original article was published in Spanish; this website summary is presented in English.

Read Original Article
ISSUE 05
Revista Vial
Railway · Argentina
2019
RAILWAY FOUNDATION
DESIGN
Diego M. Skok · Carmine Russo
August 21, 2019
PROJECT CASE COVERAGE

San Martín Railway Embankment Foundations

A case study of the San Martín railway viaduct in Buenos Aires, where Neoloy® reinforcement was incorporated into the embankment foundation system over soft clay.

Engineering Focus
Soft-soil support and embankment load transfer

The original article was published in Spanish; the visitor-facing summary here remains in English.

Read Original Article
ISSUE 06
Geosynthetics Magazine
Railway · Permafrost
2021
EXTREME RAILWAY
REPAIR
Sanat K. Pokharel · Marc Breault
June 1, 2021
INFRASTRUCTURE CASE STUDY

NPA Cellular Confinement for Railway Repair in a Permafrost Region

Coverage of the Hudson Bay Railway repair near Churchill, Manitoba, following flood damage and challenging permafrost conditions.

Reported Repair Duration
5 Weeks

Repair duration reported in the published case study.

Read Article
ISSUE 07
Geosynthetics Magazine
Heavy Loads · Working Platform
2020
HYBRID HEAVY
LOADS
Sanat Pokharel · Timothy Yii
Marc Breault · Meisam Norouzi
WORKING PLATFORM CASE STUDY

High-Strength Cellular Confinement and Geogrid Hybrid Reinforcement

A case study of a compressor-station working platform on soft subgrade in Alberta using a hybrid system combining NPA cellular confinement and biaxial geogrid.

22.8% Total project cost savings
42.3% Granular fill savings
Read Article
01 / 07

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