Modern Techniques for Concrete Pavement Design

Transcription

1 Modern Techniques for Concrete Pavement Design Robert Rodden, P.E. Director of Technical Services & Product Development American Concrete Pavement Association

2 km of Paved Roadway by Country kilometers Source: CIA s World Factbook

3 km of Paved Roadway per km 2 AREA 3,00 2,84 2,50 2,00 1,50 1,41 1,35 1,81 1,62 1,00 0,50-0,45 0,49 0,16 0,05 0,04 0,02 kilometers Source: CIA s World Factbook

4 m of Paved Roadway per PERSON 16,0 14,0 12,0 14,0 15,0 14,8 11,9 10,0 8,0 6,0 7,5 5,4 7,9 8,0 4,0 2,0-1,3 1,2 0,4 meters Source: CIA s World Factbook

5 GDP per m of Paved Roadway $ $ $8.000 $6.000 $4.000 $2.000 $ $5.694 $5.092 $4.240 $3.379 $3.765 $3.868 $2.626 $1.924 $2.064 $1.064 $- meter Source: CIA s World Factbook

6 Opportunity is Knocking on the Door

7 Concrete Pavements

8 123 Yrs of Success and Performance

9 Where are Concrete Pavements? Australia Austria Belgium Bolivia Brazil Canada Chile China Costa Rica Czech Republic Dominican Republic Ecuador El Salvador France Germany Ghana Guatemala Honduras India Indonesia Iran Italy Japan Kenya Kingdom of Bahrain Mexico Netherlands New Zealand Nicaragua Norway Pakistan Peru Poland Portugal Puerto Rico Russia South Africa South Korea Spain Sweden Switzerland Taiwan Thailand Turkey Uruguay United Kingdom USA and others ACPA isn t aware of yet...

10 ...If You Should be or Are on the List GET INVOLVED!!!

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13 Pavement Engineering

14 Pavement Engineering the art of molding materials we do not wholly understand into shapes we cannot precisely analyze so as to withstand forces we cannot assess in such a way that the community at large has no reason to suspect our ignorance.

15 Design for What?

16 DOWEL BARS Belgium

17 CLIMATE Chile PANEL WIDTH Peru Bolivia TRAFFIC CURING Guatemala

18 China Understand Heavy Traffic! 640,000 km added in the last 4 years!?!?!? 70%+ is Concrete

19 CONSTRUCTION METHOD El Salvador Spain CURB AND GUTTER Mexico USA SHOULDER GEOMETRICS

20 REINFORCEMENT USA

21 South Africa DRAINAGE

22 SURFACE TEXTURE Kenya

23 JOINT SPACING USA

24 Bolivia MATERIALS Ecuador Dominican Republic ETC

25 Precast Concrete Pavement in the US

26 Precast Concrete Pavement in Indonesia 35 km Built Using this Method

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29 Have to Also Consider Performance!

30 Design How?

31 Much Variety in Design Methods DARWin-ME, WinPAS/AASHTO 93 TCPavements cncpave VENCON2.0 Custom Catalog IRC Guide StreetPave, PCA Method IP-07/2004 CHAUSSEE2 FAARFIELD, AirPave, ACI 330, etc. USA, Canada Chile, Guatemala, Peru South Africa Belgium, Netherlands Germany India Australia, Portugal, USA, Canada, Uruguay Brazil Canada USA

32 AASHTO 93/WinPAS

33 AASHO Road Test ( ) Included both concrete and asphalt designs Included a wide range of axle loads and pavement crosssections

34 Subgrade = Clay Soil

35 AASHO Test Traffic Max Single Axle Max Tandem Axle

36 Some AASHO Results Average Serviceability of Surviving Sections

37 AASHTO Design Procedures & Changes AASHO Interim Guide for the Design of Rigid and Flexible Pavements 1972 AASHTO Interim Guide for the Design of Pavement Structures Consolidate + update 1981 Revised Chapter III on Portland Cement Concrete Pavement Design Minor revisions 1986 Guide for the Design of Pavement Structures - Major revisions to subgrade support; added overlays, reliability, LCCA, pavement management 1993 Revised Overlay Design Procedures Addressed deficiencies in 86 overlay design; basis of WinPAS 2010 DARWin-ME TM Mechanistic principles added

38 Concrete Pavement Design Equation Standard Normal Deviate Overall Standard Deviation PSI Depth D Log Log(ESALs) = Z R * s o * Log(D + 1) * Modulus of Drainage ( D+1) Rupture Coefficient Terminal Serviceability [ 0.75 S' ] c * C d * D ( p t )*Log EMPIRICAL DESIGN * J * D ( E c / k ) Load Transfer Modulus of Elasticity Change in Serviceability 0 25 Modulus of Subgrade Reaction

39 WinPAS Makes it Easy

40 PCA/StreetPave

41 StreetPave s Origins PCA thickness design methodology for JPCP first published in 1966 used slab stress/fatigue as the sole design criterion for determining thickness updated in 1984 failure by erosion (pumping) edge support

42 StreetPave s Origins StreetPave released in 2005 by ACPA tailored for streets and roads improvements included: enhanced concrete fatigue model w/reliability component ability to analyze tridem axles in the traffic spectrum new recommendations for dowel bars, joint spacing, subgrade/subbase moduli, etc. side-by-side design comparison to asphalt sections

43 Fatigue Total Damage Cumulative damage: FD total = FD single + FD tandem + FD tridem where, FD total = total fatigue damage, % FD single = fatigue damage from single axle loads, % FD tandem = fatigue damage from tandem axle loads, % FD tridem = fatigue damage from tridem axle loads, % MECHANISTIC DESIGN but validated

44 Predicted log (N) Fatigue - Model Comparison Stress ratio, SR StreetPave 50 percent) StreetPave 90 percent) PCA

45 Faulting Total Erosion Cumulative erosion: ED total = ED single + ED tandem + ED tridem where, ED total = total erosion damage, % ED single = erosion damage from single axle loads, % ED tandem = erosion damage from tandem axle loads, % ED tridem = erosion damage from tridem axle loads, % EMPIRICAL DESIGN

46 StreetPave Design Inputs Design Life Reliability % Slabs Cracked Traffic Volume Load Growth Distribution K-value Subgrade & Subbase(s) Thickness Modulus Edge Support Dowel Bars Concrete Strength Modulus of Elasticity

47 StreetPave12 Overlays Traffic Subgrade Doweling Etc.

48 TCPavements

49 Influence of Slab Geometry on Stresses 4,5m x 1m 2.25 m x 1 m Maximun tensile stress = Kg/cm2 Maximun tensile stress = 5.22 Kg/cm2 Principal stresses on the top of the slab, Red is tensile strength Deformation of the slab

50 Position of the Loads and Dimension of the Slabs AASHTO Design TCP Design

51 Slabs Sizes and Thickness For Same Top Stress (2.5 MPa) Thickness: 250 mm (10 ) Concrete Slabs 4,5m x 3,6m Thickness: 160 mm (6,3 ) Concrete Slabs 1.8m x 1.8 m

52 Characteristics of TCP Design Small slabs (1.4 to 2.4) meters long (5ft-8ft) Less curl/warp; smaller crack width Granular base (fines < 8%) 15 cm thick Less pumping/faulting potential Normal or fiber reinforced concrete Geotextile between the subgrade and base, if needed Thin joint cut (<2.5 mm wide) No joints sealing Optimized dowel bar system or no dowels Lateral confinement with curb, shoulder, vertical steel pins or FRC Widened outer lane

53 TCP Design Cumulative fatigue damage, like StreetPave Islab 2000 runs for stresses; NCHRP 1-37 for fatigue ESALs used for simplicity Environment considered in calculations MECHANISTIC DESIGN but validated

54 MEPDG/DARWin-ME

55 Mechanistic-Empirical Design + = Mechanistic Elements Empirical Elements Pavement Performance Prediction

56 M-E Design Basics Mechanistically: Calculate critical pavement response (i.e., stresses, strains, and deflections) due to: Traffic loading. Environmental conditions. Accumulate damage over time. MECHANISTIC + EMPIRICAL DESIGN Empirically: Relate damage over time to pavement distresses through calibrated models, e.g.: Cracking, Faulting, Roughness in JPCP. Punchouts, Crack Width, Roughness in CRCP. Accumulate damage over time.

57 INPUTS, INPUTS, INPUTS!!!!

58 INPUTS, INPUTS, INPUTS!!!!

59 OUTPUTS, OUTPUTS, OUTPUTS!!!

60 Agencies Licensing/Evaluating DARWin-ME Software as of 9/8/11 Licensing: 16 DOTs 6 Canadian Provinces Evaluating: 8 DOTs Other Licensee s: FHWA ACPA Cement Assoc of Canada Cemex 8 Consultants City of LA 4 Universities Alaska Hawaii DE

61 Agencies Licensing/Evaluating DARWin-ME Software as of 4/25/12 Licensing: 29 DOTs 5 Canadian Provinces Evaluating: 4 DOTs Other Licensee s: FHWA ACPA Cement Assoc of Canada Cemex 19 Consultants City of LA 14 Universities APA of IN Maricopa County Alaska Hawaii 5 PAID LICENSES OUTSIDE US & CANADA; Several countries looking at applicability DE

62 BALANCING ACT

63 Design is More than Just Inputs!

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65 The Digital Toolbox

66 Webinars and On-Demand Learning Troubleshooting Design Software Safety by the Paving Train The Paving Process Curing Joint Design and Layout Constructing Smooth Pavements LCCA Testing Procedures Concrete Overlays Recycling Stringless Paving Subgrades/Subbases Distress Prevention ETC..

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69 COMING SOON!! Concrete Pavement Wiki wiki.acpa.org

70 Thank you! QUESTIONS? Robert Rodden, P.E. (company site) apps.acpa.org (free apps site) resources.acpa.org (resources site)