Geocomposite Capillary Barrier Drain Geocomposite Capillary Barrier Drain (GCBD) for limiting moisture changes (GCBD) for limiting moisture changes

in pavementsin pavementsNCHRP Highway IDEA ProgramNCHRP Highway IDEA Program

John C. Stormont, PhD, PE Univ. of New MexicoJohn C. Stormont, PhD, PE Univ. of New MexicoKaren S. Henry, PhD, PE, USACEKaren S. Henry, PhD, PE, USACE--ERDCERDC--CRRELCRREL

Ruth Roberson, Minnesota DOTRuth Roberson, Minnesota DOT

OutlineOutline

1.1. Geocomposite capillary barrier drain Geocomposite capillary barrier drain 2.2. Project backgroundProject background

•• Type 1 project & resultsType 1 project & results•• Muddy roads resultsMuddy roads results

3.3. Type 2 (current) projectType 2 (current) project•• Phase 1 resultsPhase 1 results•• Phase 2 Phase 2

•• DescriptionDescription•• StatusStatus

4.4. GCBD challengeGCBD challenge

Patent No. Patent No. 6,152,653, November 6,152,653, November

20002000

GCBD DevelopmentGCBD Development

1997

IDEA Phase 2

IDEA Phase 1

Sponsors:NMDOT Sponsors:

NHCRP- IDEANYDOTVAOTNHDOT

Lab proof of concept

Sponsors:VAOT

Muddy RoadsOptimize propertiesLarge-scale lab demonstration

200420031998 1999 2000 2001 2002

Sponsors:NHCRP-IDEAMnDOTNYDOT

NM DOT

Field demo with limited measurements

2005 +

Field demo with extensive measurements and design calibration

The GCBD drains water from soils The GCBD drains water from soils beforebefore they saturatethey saturate

The GCBD is a new type of drainage geocompositeThe GCBD is a new type of drainage geocomposite

Capillary BarrierCapillary Barrier

••LargeLarge--poredpored••In fine soil above water tableIn fine soil above water table••Diverts downward infiltrating waterDiverts downward infiltrating water•• Reduces upward, unsaturated flowReduces upward, unsaturated flow

Transport layerTransport layer

Accepts water at higher Accepts water at higher suctions than the suctions than the capillary barrier, and is capillary barrier, and is more conductive than the more conductive than the adjacent fine soiladjacent fine soil

soil

soil

transport layertransport layer

capillary barrier (geonet)capillary barrier (geonet)

separator (geotextile)separator (geotextile)

1.1. Downward moving water is Downward moving water is stopped by capillary barrierstopped by capillary barrier

Subgrade

2.2. The transport layer The transport layer conducts waterconducts water

3.3. Water Water drains laterally drains laterally in the transport in the transport layer due to layer due to slopeslope

How a GCBD works (in a road)How a GCBD works (in a road)

Base

GCBD has multiple functions GCBD has multiple functions ––each improves performanceeach improves performance

•• Drainage (unsaturated, Drainage (unsaturated, saturated)saturated)Accelerates drying of baseAccelerates drying of base

•• Capillary barrier to upward Capillary barrier to upward flowflow

•• ReinforcementReinforcement•• SeparatorSeparator

Applicable to paved and Applicable to paved and unpaved roadsunpaved roads

Capillary Barrier Capillary Barrier Prevents wetting from Prevents wetting from shallow water table or shallow water table or freezefreeze--induced water induced water

movementmovement

ReinforcementReinforcement

Maintains Maintains distinct distinct interface interface between base between base and subgrade and subgrade

SeparationSeparation

Increases base Increases base bearing bearing capacitycapacity

Reduces Reduces stress reaching stress reaching subgradesubgrade

NCHRP Highway IDEA Type 1 ProjectNCHRP Highway IDEA Type 1 Project

1.1. Selected optimal transport Selected optimal transport layerlayer

2.2. Rained on cracked Rained on cracked pavementpavement

•• GCBD drained water from GCBD drained water from unsaturated base courseunsaturated base course

•• Accelerated base course Accelerated base course dryingdrying

•• Protected subgrade from Protected subgrade from wettingwetting

020

4060

80100

120

CSFM

F300TG

1000C

FMC

FHNYLSO

RBX

HTXTG

LASSNW

FGTC

M5

FGW

KTR

11TC

M1

GEO

9EG

LASS

Cap

illary

rise

(cm

)

Dense-Graded BaseAsphalt

SubgradeGeotextile

Ditch DrainHoleTensiometer

GCBD or Separator (Control Section)

1

0

0 3 61 2 4 5

Hei

ght (

m)

Length (m)

Separator

TransportLayer

NetExperimental Experimental apparatusapparatus

Suction head 13 mm Suction head 13 mm above interface, 1 hr. above interface, 1 hr. storm (10 year storm (10 year design storm)design storm)

0

100

200

300

400

500

600

0 1 2 3 4 5 6Elapsed time (days)

25 26 27 29 32

0

100

200

300

400

500

600

25 26 27 29 32

AC

-P

AV

EM

EN

T

BA

SE

SU

BG

RA

DE

GC

BD

CRACK

26 25

29

2728

303132

Vermont Agency of TransportationVermont Agency of TransportationUniversity of VermontUniversity of VermontERDCERDC--CRRELCRRELGeo Design Geo Design -- John LensJohn LensApplied Research AssociatesApplied Research Associates

Muddy Roads, Windsor, VTMuddy Roads, Windsor, VT

CESeparatorCMGCBDCW

75’ 100’

Weighted CBR, 0-3 inches depth

0

5

10

15

20

25

30

35

40

45

4/6/2003 4/8/2003 4/10/2003 4/12/2003 4/14/2003 4/16/2003

CB

R

GCBDControl-WestControl-Middle

Spring thaw, 2003, GCBDSpring thaw, 2003, GCBD

IDEA Type 2 Project IDEA Type 2 Project –– GCBD for GCBD for limiting moisture changes in limiting moisture changes in

pavementspavements

Facilitate transfer of GCBD technology into Facilitate transfer of GCBD technology into practice practice –– paved roadspaved roads

1.1. GCBD connection to edge drain pipe and GCBD connection to edge drain pipe and construction details (completed)construction details (completed)

2.2. MnMn Road test section installationRoad test section installation•• FHWA pooled fund FHWA pooled fund –– TPF 5(126)TPF 5(126)−− MI, NY, MNMI, NY, MN•• Construction JuneConstruction June--August, 2006August, 2006

Engineer Research and Development CenterUS Army Corpsof Engineers

Laboratory testing of GCBD-edgedrain pipe configuration

Water added at surface cracks

Base Course Material

Sub Grade MaterialGravel

TGLASSGeo GridTGLASS

Tensiometers

Pavement

Water collected from edgedrain pipe

-100

0

100

200

300

400

500

600

700

0 50 100 150 200

Time, minutes

Cum

mul

ativ

e W

ater

C

olle

cted

, ml

With GCBD Without GCBD

Subgrade

Base course

Fine filter aggregate

GCBD

Slotted drain pipe

Subgrade

Base course

Fine filter aggregate

GCBD

Slotted drain pipe

Optimal connection to subsurface Optimal connection to subsurface drainagedrainage

Minnesota Department of Minnesota Department of Transportation Transportation –– MnRoadMnRoad ProjectProject

+OWP

+IWP

CL

-IWP

-OWP

400 }{TGeo

400 }{

TNo Geo

Sensor Cabinet

N

E

S

W

Sensor Cabinet

Research PlanResearch Plan

100

TNoGeo

4" HMA

Clay Loam

6” DGB6”

10”

13”

24”

8”Sensor Locations

HDS

CS616 ECH2OTE

MnRoadMnRoadInstrumentationInstrumentation

GCBD ChallengeGCBD Challenge

•• Who will license the patent?Who will license the patent?

•• Transport layer manufacturerTransport layer manufacturer•• Geotextile manufacturerGeotextile manufacturer•• Geonet manufacturerGeonet manufacturer•• Do we need venture capital?Do we need venture capital?