Short summary presentation of rd v1

R&D with World Leading Researchers Evaluation of Neoweb pavement in dynamic wheel load testing Impact of Neoweb on track maintenance cycles Contribution of Neoweb to load bearing and s

PRS Research

R&D with World

Leading Researchers

Evaluation of Neoweb

pavement in dynamic

wheel load testing

Impact of Neoweb on track maintenance cycles

Contribution of Neoweb to load bearing and stress distribution

Evaluate reinforcement performance of Neoweb

in road-base test site

Department of Transportation

(DOTs) of Kansas, Iowa,

Missouri, Nebraska & NY;

Civil Engineering Dept.,

Kansas State University, USA

Transport Technology Center, Inc (TTCI), Association of American Railroads (AAR);

Facility for Accelerated Testing (FAST), Colorado, USA

Institute of Geotechnical Engineering, Clausthal University, Germany

KOAC-NPC Road Testing & Certification Institute, Holland

R&D with World

Leading Researchers

Neoweb demonstration

project – Chennai-Tada

Highway, India

Earth-quake simulation

on shaking table with Neoweb gravity wall

Neoweb load support under static & cyclic loading

Circular track bed infrastructure testing

• L&T ECC – India's largest

construction firm

• IIT – India Institute of

Technology, Madras

• NHAI – National Highway

Authority of India

Dept of Civil Engineering and Mechanics, University of Delaware, USA, National Institute of Rural Engineering,T sukuba, Japan

Civil, Environmental, and Architectural Engineering Dept., Univ of Kansas,

USA

Proving & testing center, Sherbinka Station, Russian Railway Research Institute

(VNII ZhT)

Clausthal University, Germany

Institute of Geotechnical Engineering

Phase I - Road Experiment - Laboratory Testing

Dynamic load tests with frequency of 1 cycle/sec;

Max load Fmax - 300 kN/m²; Min load Fmin - 25 kN/m²

Clausthal University Road Experiment

Phase I – Test Results – On Dry Sand

Load Settlement – Dry Sand Results of Dynamic Plate Tests

• Load-bearing capacity of geocell reinforced soil improved up to 5x

• Settlementcan be reduced due

to geocell mattress up to 80%

• Vertical stressesin subgrade can be reduced up to 40%

* Dependent on infill material & cell height

REINFORCED

UNREINFORCED

Clausthal University Road Experiment

Phase II – Rehabilitation of K27

Road Sections

Clausthal University Road Experiment

Phase II – Test Results

‹ Influence of Geocell Mattress on

Subgrade Stresses

› Static Plate Loading on Top

of Granular Layer

fi Back Calculation Results – Unreinforced Layer vs Reinforced Layer

• Modulus Ratio: E sb Reinforced 100 [MPa] / E sb Unreinforced 500 [MPa] = 5

Clausthal University Road Experiment

Phase III – Dynamic Loads & Falling

Weights Deflectometer (FWD) Measurements

FWD measurements after long-term heavy trafficking:

• Layer modulus for Neoweb reinforced 40 cm layer =

70 cm unreinforced layer

• Field results confirmed by back calculations

Differences between stresses in reinforced & unreinforced sections are ~ 34-40%

Dynamic Trafficking

FWD Measurements

Deflections of 70 cm base = 40 cm Neoweb reinforced base

KOAC - NPC

Geosynthetics Road-Base Trial, Holland

KOAC – NPC Test Program

• Objectives

– Evaluate leading “geogrids”

performance in road base

– PRS only geocell /

manufacturer

• Test Assumption

– Reinforcement can only be

measured accurately only by

in-situ testing

• Special Controlled Site

– Large, enclosed hangar

protected from weather

1.5m 1.5m

1.5m

1.5m

4 m

4 m

1 2

2  test locations  within  section

Road Base Thickness Reduction

Factor – HIGH QUALITY INFILL

Deflections

Shape of deformation curve is primary parameter to derive reinforcement effect/graph

Back-calculation

Iterative procedure used to determine modulus of pavement layer

ROAD BASE THICKNESS  REDUCTION FACTOR STATION

10A1 10A3

Unprecedented Results

• Neoweb Roadbase Thickness Reduction Factors exceeded all previously known values - 0.73 mean!

– Factor for geogrids historically never exceeded 0.5

– Factor in this Trial for all geogrids was lower than 0.5

• Test evaluation for all products was therefore limited to 0.5!

Testing - Conclusions

Test Results

1 Only product that was able to be

tested with inferior infill

2 Highest Road Base Thickness

Reduction Factor of any tested

product *

– High quality infill – avg 43%

– Inferior quality infill – 31.5%

( * value limited to maximum of 50% by

testing organization)

3 Neoweb performance above and

beyond geogrid capabilities

Conclusions

1 High engineering stiffness and strength

2 Decreased subgrade stress

3 Increased bearing capacity

4 Long term durability

5 Reduced pavement thickness

– Lowers costs – Saves aggregate resources – Faster installation

– Reduces environmental impact