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TCP Design(THIN CONCRETE PAVEMENTS)

Juan Pablo Covarrubias

Washington2008

Type of Pavement we are Talking About

PERFORMANCE OF CONCRETE PAVEMENTSThe basic performance principles of Concrete Pavements

In Chile, the slabs are always curled with the edges lifted up, day and night.

DEFORMATION OF A SLAB15 cm thick, 4 m. long

EFFECT OF SUBGRADE STIFFNESSArmaghani 1993

EFFECT OF SUBGRADE STIFFNESSNot bonded (polyethylene)

EFFECT OF SLAB LENGTHcantilever1/3 Lcantilever1/3 Lcantilever1/4 Lcantilever1/4 LLength 4,5 m. cantilever = 1,13 mLength 1,8 m. Cantilever = 0,45 m

EFFECT OF SLAB LENGTH ON SHRINKAGE AND CURLINGa > 1

EFFECT OF SLAB LENGTH ON CURLING

450 cm x350 cmThickness= 18 cmDelta T=-14 C LinearCurling = 2.41 mm140 cm x175 cmThickness= 18 cmDelta T=-14 C LinearCurling = 0.49 mm

SLAB LENGTH AND CURLINGHolland 20023,8 m4,5 m

EFFECT OF TIE BARS ON CRACKING OF SLABSHiller and Springenschmid, 2004

Development of the Designby TCPavementsResearch at the University of IllinoisGenerate Design Method.Coordinate tests at international level

Loads of Trucks on SlabsMinimum Requirement for TCP design:Maximum slab length less than L Maximum slab width less than Dx (1/2 lane)

LOADING OF LONG AND SHORT SLABS

Efect of Loads and Slab Geometry on Stresses

One Axel at the EdgeX

LOADS AND STRESSES ON A SLAB WHITH ROCKING

RELATION: length - thickness - tensile stress

Sheet4

Sheet1

RELACION TENSION - LARGO DE LOSA

L (cm)Lh (cm) (kg/cm2)ancho (cm)Momento (kg/cm2)P por eje para apoyar losa

500500155335014944052310.41

50012673501196504184

5001080350996603487

5008100350797752790

45045020323501614246277

45015433501211324708

4501254350968403766

4501065350807483138

450881350646612511

45025263502018197846

4004001534350956264184

4001243350765323348

4001051350638382790

400864350510482232

3502020350976154882

3503501526350732203661

3501233350586242929

3501039350488292441

350849350391371953

1751751571751835458

1751281751466366

17510101751227305

175812175989244

120120153120862215

120124120693172

120105120573143

12086120464115

L (cm)Lh (cm)ancho (cm)Momento (kg/cm2)

450450.0020350161424

450.0015350121132

450.001235096840

450.001035080748

450.00835064661

3503502035097615

350.001535073220

350.001235058624

350.001035048829

350.00835039137

175175.00151751835

175.00121751466

175.00101751227

175.008175989

120120.0015120862

120.0012120693

120.0010120573

120.008120464

5002535030763010767

500203502461378613

500153501846496460

500123501477625168

500103501230744307

5008350984923445

450253502492249690

450203501993307752

450153501495405814

450123501196504651

45010350997603876

4508350797753101

400253501969198613

400203501575246891

400153501181325168

40012350945394134

40010350788473445

4008350630592756

350253501507147537

350203501206186029

35015350904244522

35012350724303618

35010350603363015

3508350482452412

1752517537741884

1752017530151507

1751517522661131

175121751818904

175101751519754

175817512111603

120251201772886

120201201422709

120151201063532

12012120854425

12010120714354

1208120575284

L (cm)height (cm) (kg/cm2)width (cm)Moment (MPa)Axel load for (kg)

5002535030763010767

500203502461378613

500153501846496460

500123501477625168

500103501230744307

5008350984923445

450253502492249690

450203501993307752

450153501495405814

450123501196504651

45010350997603876

4508350797753101

400253501969198613

400203501575246891

400153501181325168

40012350945394134

40010350788473445

4008350630592756

350253501507147537

350203501206186029

35015350904244522

35012350724303618

35010350603363015

3508350482452412

1752517537741884

1752017530151507

1751517522661131

175121751818904

175101751519754

175817512111603

120251201772886

120201201422709

120151201063532

12012120854425

12010120714354

1208120575284

Sheet2

Length (m)Length (cm)Thickness (cm)Moment (MPa) (MPa)

4.5450252492242.4

4.5450201993303.0

4.5450151495404.0

4.5450121196505.0

4.545010997606.0

4.54508797757.5

1.751752537740.4

1.751752030150.5

1.751751522660.6

1.751751218180.8

1.751751015190.9

1.751758121111.1

Sheet3

EFFECT OF SLAB LENGTH ON CURLING AND OWN WEIGHT STRESSES

450 cm x350 cmThickness= 18 cmDelta T=-14 C LinearTop Tensile stress= 1.40 MPa140 cm x175 cmThickness= 18 cmDelta T=-14 C LinearTop Tensile stress= 0.18 MPa

Project in GuatemalaSlabs 4,5 m x 3,5 m x 24 cm

Project in Guatemala Slabs 1,8 m x 2,1 m x 15 cm

Summary Guatemala Project Thin slabs with 30 cm widening

FINITE ELEMENTS ANALISIS

Thicknesses for Same Stresses and Slab Lengthcmcm

LOAD POSITION AND SLAB SIZE

Top and Bottom Stresses for Length and Thickness

CHARACTERISTICS of TCP DesignSmall slabs (1,8 by 2.4 meters)Granular base (fines < 6%) 15 cm thickImpermeable layer between the sub grade and sub base, if neededThin joint cut (2 mm thick)No joints sealing No dowel bars or tie barsLateral confinement with curb, shoulder or vertical steel pinsWidened outer lane (30 cm)

DesignDesign method being used:

Design with AASHTO with normal slab size (4.5 m long)Determine by finite elements the stresses within the concrete of the slab for the AASHTO designCalculate slab thickness by iteration with ISLAB2000 with the new configuration of slab size and wheel positions (one set of wheels on each slab) to obtain the same stresses than the AASHTO design.

The result, by using this new design approach, is a thinner concrete pavement with the same stresses as AASHTO design

Construccion Cost

TCPH TradicionalAsfaltoEE DiseoEspesorCosto Km-PistaEspesorCosto Km-PistaH-TCP% AhorroEspesorCosto Km-PistaAsf-TCP% Ahorro 50,000 8cm $ 69,041 - --- 5cm $ 71,808 $ 2,767 4% 100,000 8cm $ 75,000 - --- 7cm $ 86,000 $ 11,000 13% 1,250,000 10cm $ 81,715 15cm $ 113,400 $ 31,685 28% 9cm $ 101,803 $ 20,089 20% 3,000,000 12cm $ 94,389 18cm $ 132,411 $ 38,022 29% 10cm $ 116,165 $ 21,776 19% 15,000,000 15cm $ 113,400 22cm $ 160,000 $ 46,600 29% 13cm $ 137,389 $ 23,989 17% 68,000,000 18cm $ 132,411 28 cm $ 195,782 $ 63,371 32% 18cm $ 186,889 $ 54,478 29% 160,000,000 22 cm $ 157,759 30 cm $ 208,456 $ 50,696 24% 22cm $ 216,885 $ 59,126 27%

*Prices from Chile

Long Term Costs:

Research at U. de Illinois

Sub Grade CBR 3%

Geotextile and Granular Base

Granular Base less 6% Fines

Concrete Slabs finished

ATLAS Machine

Experiences

Constructed Projects

Guatemala

BM3 Acceso CA9 Sur (Puente Villalobos)DescriptionStart Year: end 2005Length: 1.68km120.000.000 Esals15 years designCiudad de Guatemala, GuatemalaHighwayPavement structure21 cm thickGranular base and asphalt base14.40m to 21.60m Witdh

GuatemalaRuta CA-01 Occidente Ciudad San Cristobal - San Lucas (Road to Antigua)DescriptionYear 2006Length: 11.07km80.000.000 EsalsCiudad de Guatemala Sacatepquez, GuatemalaHighwayPavement Structure17cm thickGranular base and asphalt base14.40m Witdh

Configuration of Sugar Cane Vehcle (VCMEM)

Hoja1

MODELADO DE VEHICULO TIPO

TOTAL

No. de Ejes11111117

No. de Neumticos288444434

Peso eje (TON)6242020202020130

LIBRAS

6.614.114.19999

ESAL0.68301345548.39399132854.048028225624.386526444124.386526444124.386526444124.3865264441110.671138786

1.00E+08

22

4545454.54545455

3863636.36363636

FEQ (Losa e=29 pt=2)0.25512.56.076.076.076.076.0743.105

FEQ (Losa e=26 pt=2)0.255512.46.066.066.066.066.0642.9555

FEQ (Losa e=29 pt=2.5)0.25512.112.145.2545.2545.2545.25205.455

FEQ (Losa e=26 pt=2.5)0.25511.95.925.925.925.925.9241.755

FEQ (Losa e=29 pt=2)0.25512.512.449.5249.5249.5249.52223.235

FEQ (Losa e=26 pt=2)0.255512.212.248.0748.0748.0748.07216.9355

29

31

30.2

Hoja1 (2)

MODELADO DE VEHICULO TIPO

TOTAL

No. de Ejes11111117

No. de Neumticos288444434

Peso eje (TON)6242020202020130

LIBRAS

6.614.114.19999

ESAL0.68301345548.39399132854.048028225624.386526444124.386526444124.386526444124.3865264441110.671138786

1.00E+08

22

4545454.54545455

3863636.36363636

FEQ (Losa e=29 pt=2)0.25512.56.076.076.076.076.0743.105

FEQ (Losa e=26 pt=2)0.255512.46.066.066.066.066.0642.9555

FEQ (Losa e=29 pt=2.5)0.25512.112.145.2545.2545.2545.25205.455

FEQ (Losa e=26 pt=2.5)0.25511.95.925.925.925.925.9241.755

FEQ (Losa e=29 pt=2)0.25512.512.449.5249.5249.5249.52223.235

FEQ (Losa e=26 pt=2)0.255512.212.248.0748.0748.0748.07216.9355

29

31

30.2

VCMAN

ESQUEMA DEL VEHCULO VCMAN

TOTAL

Nmero de Ejes11111117

Nmero de Neumticos288888850

Peso Mximo (Ton)6242020202020130

Ejes Equivalentes a 18,000 lbs0.25512.56.076.076.076.076.0743.105

Longitud (m)18101038

VCMEC

VCMAM

TOTAL



Peso Mximo (Ton)62420202020202020170

Ejes Equivalentes a 18,000 lbs0.25512.56.076.076.076.076.076.076.0755.245


VCMEM

TOTAL



Peso Mximo (Ton)6292525252525160

Ejes Equivalentes a 18,000 lbs0.263115.915.915.915.915.9111


Tensions with Sugar Cane Vehicle (VCMEM)

ConclutionTCP design allows for:Reduction in thickness, reducing construction costs and keeping the normal performance as traditional designIncrease of axel loads, reducing transportation costs, congestion and contamination.

THANK YOU

www.tcpavements.com

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