ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 1 MODELS FOR PERMANENT DEFORMATION FOR BITUMINOUS BOUND MATERIALS IN FLEXIBLE PAVEMENTS Deliverable 11

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 2 SURVEY PRESENTATION: Survey Models Test Types Required Laboratory Test Data Further Steps Discussion and Questions Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 3 SURVEY MODELS Routine LevelAdvanced Level Francken / BRRCSHRP – Level II SPDM / ShellErkens / Delft SHRP – Level IMaxwell model / ISTU DBN / ENTPE Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 4 SUMMARY TEST TYPES DSR Tests (Binder)Francken Shear Tests (SST)SHRP Uniaxial Creep Test Erkens Uniaxial Dynamic Test SPDM Triaxial Creep TestDBN Triaxial Dynamic Test Francken, ISTU Uniaxial Tension TestErkens Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 5 Survey Models Test Types Required Data Further Steps REQUIRED LABORATORY TESTS LAB TEST MODEL Uniaxial CreepTest Uniaxial Rep.Load Test TriaxialDynamic Test Triaxial CreepTest UniaxialTension Test RSST-CH(SST) FS-S (SST) VolumetricTest (SST) Uniaxial StrainTest (SST) DSR Tests Francken / BRRC XX SPDM / Shell X(X) SHRP – Level I XX SHRP – Level II XXX ACRe / Delft XX Maxwell model / ISTU X(X) DBN / ENTPE X... test performed at ISTU–Lab... SHELL... TRL

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 6 FURTHER STEPS Literature study ( models ) Calibration of selected models Validation of the selected models Selection of potential models for validation Data Lausann e Data Nantes Data DART Laboratory Test Data Deliverable 11 Deliverable 28 Survey Models Test Types Required Data Further Steps Selection of models for validation ?

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 7 FURTHER STEPS Survey Models Test Types Required Data Further Steps Activity of PartnerSchedulePartner Pre-selection of models for validation WP5 Designation of required laboratory test data WP5 Selection of historical data - Nantes Test Trackuntil LCPC Material transport and specimen preparationuntil ISTU Laboratory Tests at ISTUfrom ISTU-Lab Other laboratory tests (SHELL, TRL, DRI, LCPC)from all WPP Analysis of test track datafrom ISTU Calibration (FE-code implementation and simulations) spring 2005ISTU ValidationSummer 2005ISTU Deliverable ISTU

Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 8 Permanent Deformation Model by Francken/BRRC Survey Models Test Types Required Data Further Steps Basic principles: Material model Based on triaxial dynamic tests

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 9 Survey Models Test Types Required Data Further Steps Francken / Basic principles:

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 10 Francken / Basic principles: Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 11 Key equations: Survey Models Test Types Required Data Further Steps  p...plastic deformation  1...amplitude of vertical stress  3...lateral stress E p...plastic deformation modulus N...number of load repetitions f...load frequency f()... coefficient, dependent on the void content E*...complex elastic modulus E ∞...purely elastic or „glassy“ modulus R*...reduced modulus T...temperature V A...aggregate content [Vol %] V B...binder content [Vol %] F*...reduced shear modulus (binder) Francken / Key equations

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 12 Input parameters for the model: Complex elastic modulus E* Complex shear modulus G* of the binder Aggregate content [vol. %] Binder content [vol. %] Survey Models Test Types Required Data Further Steps Francken / Input parameters Triaxial test DSR and vol. asphalt characteristics

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 13 Rutting Prediction within the SHELL Pavement Design Method (SPDM) Survey Models Test Types Required Data Further Steps Basic principles: Rutting prediction model Multi layer theory (BISAR) Based on the ratio of the stiffness of the asphaltic mix and its bituminous binder Uniaxial repeated load tests or RSST-CH for determination of input parameters SPDM-PC program for the calculation of rut depths

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 14 Key equations: Survey Models Test Types Required Data Further Steps S mix,v Stiffness of the mix S bit,v Viscous component of the stiffness of the bituminous binder b, q... Parameters, specific for a certain asphaltic mix, determined by creep tests  0...Bitumen viscosity at the average paving temperature W eq...ESALs t w...Wheel loading time (traffic speed) h...Rut depth k...Coefficient k=C m Z 0, dynamic factor C m = 1 by default Z 0...Configuration factor  0...Contact stress of the standard wheel  av,0...Average stress in the asphalt layer resulting from one standard wheel pass h...Thickness of the asphalt layer SPDM / Key equations

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 15 Survey Models Test Types Required Data Further Steps SPDM / Input parameters Input parameters for the model: Traffic: axle loads, wheels per axle, axles per day and line, contact stress, rate of traffic growth per year, design period, loading time Climate: MMAT (Mean Monthly Air Temperature in °C) Material characteristics: penetration of the bitumen at 25°C, softening point of the bitumen, polymer modified bitumens: viscosities at two temperatures, mix composition (Vol.% bitumen, Vol.% aggregate), creep characteristics (parameters q and b) Structure: total thickness of asphalt layers, thickness of sub- base, Poisson’s ratio of asphalt layers, of the sub-base and of the subgrade, modulus of elasticity of the sub-base and the subgrade

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 16 Rutting prediction model within the Strategic Highway Research Programme (SHRP) – Level I Basic principles: Rutting prediction model RSST-CH for determination of the input parameters Traffic and climate assumptions included into model Survey Models Test Types Required Data Further Steps kPa ,00010,000 RSST Belastungszyklen WT 8-1 WT 8-3 WT 9-1 5% RSST load cycles Permanent shear deformation  p

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 17 Compare N supply with N demand Select pavement structural section Select trial mix From simple shear test(s) at T c select N supply for predetermined allowable rut depth Select multiplier M for N demand to reflect design reliability and variabilities in N supply and N demand Traffic, Environment N supply < M ∙ N demand Mix not satisfactory Mix satisfactory Determine critical temperature T c Compute M ∙ N demand Convert estimated traffic to N demand at T c N supply  M ∙ N demand SHRP Level I / Basic principles

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 18 SHRP Level I / Key equations Key equations: Survey Models Test Types Required Data Further Steps N demand... applied traffic demand TCF...temperature conversation factor (to be determined for specific climatic conditions) SF...empirically determined shift factor (traffic wander, construction variability, differences between field and laboratory stress conditions, etc.) N supply...estimated load repetitions to a limiting prescribed rut depth M...reliability factor

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 19 Input parameters for the model: ESALs Temperature in form of a temperature equivalency factor Chosen reliability N supply from RSST-CH for allowable rut depth Survey Models Test Types Required Data Further Steps SHRP Level I / Input parameters

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 20 Basic principles: Based on a rheological model (see figure) FS-S, volumetric tests (SST) and uniaxial strain test (SST) for the determination of the input parameters FE analysis Permanent deformation model within the Strategic Highway Research Programme (SHRP) – Level II Maxwell model Elastoplastic branch... E0E0 E1E1 EnEn 11 nn P0P0 Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 21 Select pavement structural section Select trial mix Perform suite of tests to define mix parameters for constitutive relationship Estimate rut depth for N demand using FE solution Compare rd calc with rd allow Traffic Environment rd calc  rd allow Mix not satisfactory Mix satisfactory Response model SHRP Level II / Basic principles

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 22 Survey Models Test Types Required Data Further Steps Input parameters for the model: Traffic and climate data see Level I Parameters for the rheological model: SHRP Level II / Input Parameters Type of parameter Name of parameter Test Nonlinear Elastic Parameters C 2, C 4, C 9 Simple Shear Constant Height (Creep) C 1, C 3, C 6 and C 7 Uniaxial Strain C 5 and C 8 Volumetric Viscoelastic Parameters G*, , a T Simple Shear Constant Height (Frequency Sweep) Plastic Parameters,  y,  Simple Shear Constant Height (Creep)

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 23 Asphalt Concrete Response model (ACRe) by Erkens / Delft Basic principles: Material model Based on Desai model (figure) Uniaxial creep tests and uniaxial tension tests for the determination of the input parameters FE analysis Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 24 Survey Models Test Types Required Data Further Steps ACRe / Key equations and input parameters Key equations: I 1...first invariant of the stress tensor p...isotropic stress J 2...second deviatoric stress invariant J 3...third deviatoric stress invariant , , , n, R: model parameter

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 25 Permanent Deformation Prediction Based on a Generalized Maxwell Model Basic principles: Rheological Material model Decomposition of the Stress Tensor  Pressure volume part of the material behavior is assumed to be governed by a linear elastic model  Deviatoric parts are assumed to satisfy a viscoelastic model of a Generalized Maxwell Model Frequency sweep shear tests (FS-S) or dynamic triaxial tests at different frequencies and temperatures FE analysis Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 26 Survey Models Test Types Required Data Further Steps Constitutive Equations Deviatoric Part Volumetric Part Stress Tensor Representation K0K0 Linear elastic model G0G0 G1G1 G2G2 GnGn 11 22 nn    Generalized Maxwell model REPRESENTATION & CONSTITUTIVE EQUATIONS Permanent Deformation Prediction Based on a Generalized Maxwell Model

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 27 DATA FITTING MATERIAL MODEL MATERIAL TESTING PARAMETER elastic: G 0, G 1,... G n viscous:  1,  2,...  n RESULTS G*()  () G‘() G“() RELATIONSHIP (Tschoegl, 1988) FS-S - TEST  G*G* GENERALIZED MAXWELL MODEL G0G0 G1G1 G2G2 GnGn 11 22 nn    Permanent Deformation Prediction Based on a Generalized Maxwell Model Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 28 Survey Models Test Types Required Data Further Steps 28 x y z PERSPECTIVE VIEW OF THE FE - MESH REPRESENTATION OF A PAVEMENT IN A 3D FE - SYSTEM Permanent Deformation Prediction Based on a Generalized Maxwell Model

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 29 TIRE FOOTPRINT VERTICAL CONTACT STRESS (FE – LOAD PATTERN) Radial Tire kPa VERTICAL CONTACT STRESS (TRANSPOSED SIM MEASUREMENT) VRSPTA MEASUREMENT FE – LOAD INPUT Permanent Deformation Prediction Based on a Generalized Maxwell Model LOAD MODEL

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 30 Survey Models Test Types Required Data Further Steps mm 140 mm Pavement Load cycles Normal stresses  22 SIMULATION RESULTS Permanent Deformation Prediction Based on a Generalized Maxwell Model

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 31 Permanent Deformation Model by Di Benedetto and Neifar (DBN) / ENTPE Survey Models Test Types Required Data Further Steps Basic principles: Material model Based on a generalized Kelvin-Voigt (KV) model Calibration of the KV model by means of the Huet- Sayegh model and a viscoplastic criterion by Di Benedetto Triaxial creep tests for the determination of the input parameters Computer program EP 1 V1V1 EP 2 V2V2 EP N VNVN EP 0 V N+ 1 EP 1 EP 2 EP N E0E0  1 (T) 2 (T) N (T) (a) (b)

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 32 DBN / Basic principles Survey Models Test Types Required Data Further Steps (a) Huet-Sayegh model Used for calibration in the small strain domain (b) viscoplastic criterion by Di Benedetto Used for model calibration in case of viscoplastic flow

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 33 Survey Models Test Types Required Data Further Steps DBN / Key equations Key equations: Minimisation of: E* model...complex elastic modulus of the DBN model E* Say...complex elastic modulus of the Huet-Sayegh model n...chosen number of KV bodies ...pulsation (=2f with frequency f) i...complex number T...temperature ...viscosity as function of the temperature  p...stress  c,  c, ...functions of the temperature  0...1%/min a T …temperature translation factor (a)(b)

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 34 Survey Models Test Types Required Data Further Steps DBN / Input parameters Input parameters for the model: 3 constants for the WLF equation:C 1, C 2, T S 5 constants for the linear domain:k, h, , E ∞ Say, E 0 Say 3 constants for plastic flow: C, ,  C

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 35 DSR Visco-elastic behaviour 4 – 40 °C fatigue behaviour (SuperPave) 40 – 85 °C permanent deformation (SuperPave) Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 36 MACHINE LAYOUT PICTURE Simple Shear Tester Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 37 RSST-CH h = 0  perm. shear deformation  Haversine shear wave; typically 0,1sec on and 0,6sec off Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 38 FS-S  ss h=0 Sinusoidal deformation wave, typically 10, 5, 2, 1, 0.5, 0.2, 0.1, 0.05, 0.02 and 0.01 Hz Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 39 Uniaxial and Triaxial Tests Creep tests The applied axial load is constant, so that specimen failure does not result from sudden load pulses. Most of these tests are run in compression states of stress. Repeated Load Tests A block pulse waveform that is not symmetric is applied to the specimen. One load cycle contains a load period and a rest period. Dynamic/Cyclic Load Tests Axial symmetric load curves are applied to the test specimen. Tests can be run in tension-compression as well as in compression only. Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 40 Survey Models Test Types Required Data Further Steps Test Types / Uniaxial and Triaxial Tests

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 41 Survey Models Test Types Required Data Further Steps 1,0 m (39.4 in.) 1,5 m (59.1 in.) 3,1 m (122.1 in.) 980 kg -10 to +65 °C (14 to 149 °F) SERVO-HYDRAULIC TRIAXIAL TESTING MACHINE WBL0/050HH Testing Equipment at ISTU Vienna

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 42 Simulation of traffic load with constant cell pressure dynamic, sinusoidal axial load dynamic, oscillating cell pressure – phase displaced but of same frequency; designed to prevent radial expansion completely or in part PHASE LAG  CELL PRESSURE AXIAL LOAD RADIAL REACTION Testing Equipment at ISTU Vienna SERVO-HYDRAULIC TRIAXIAL TESTING MACHINE WBL0/050HH

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 43 stainless steel shell, up to 20 bar tension and compression – axial load compression resistant grommets installation volume measurement cell (for exact volume measuring) possible linear controlled LVDT’s for radial strains (inside) axial strain measuring with LVDT’s (inside/outside) TRIAXIAL CELL Testing Equipment at ISTU Vienna Survey Models Test Types Required Data Further Steps

ISTU Institute for Road Construction and Maintenance – Vienna University of Technology SAMARIS – Presentation Draft Deliverable 11 – WP5 Meeting Roskilde, Denmark – 23/02/04 44 Uniaxial Tension Test Survey Models Test Types Required Data Further Steps Test specimen shape used by Erkens in her ACRe model