《道路与桥梁建筑材料》课程教学课件（PPT讲稿）self healing

AreDurableAsphalt Pavements Self Healing?QIUJ.**,VANDEVENM.F.C.*WUS.**,YUJ.**MOLENAARA.A.A.(*DelftUniversityofTechnology,theNetherlands)(**Wuhan Universityof Technology,People'sRepublicof China)fuDelfte

Delft University of Technology Are Durable Asphalt Pavements Self Healing? QIU J. **, VAN DE VEN M.F.C. *, WU S. **, YU J. **, MOLENAAR A.A.A. * ( * Delft University of Technology, the Netherlands) ( ** Wuhan University of Technology, People’s Republic of China)

What is self healing?>>Continuous loadingDiscontinuous loadinglogNlog8Healingexistsinbitumenand istimeand temperature dependent!!TUDelft

2 | 15 What is self healing? Continuous loading Discontinuous loading logN log  Healing exists in bitumen and is time and temperature dependent !!

How can we measure healing?>Simple>Countable crackM>QuantitativeSelfHealingofBituminous BindersARe-BEFBEAMB2TUDelft

3 | 15 How can we measure healing? Self Healing of Bituminous Binders ➢Simple ➢Countable crack ➢Quantitative

Direct tension test with loading-healing-reloading (LHR) procedureHealingLoadingReloadingReloadingLoadingHealing10mm/min10mm/min5min,30mindisplacementanddisplacementspeedat0-C3hoursat20~Cspeedat OrCBOFrelodingahal×100%H%Unloadatpost-peakFiuobaetargetelongationTEaneTUDelft4|15Test time

4 | 15 Direct tension test with loading-healing￾reloading (LHR) procedure Loading Healing Reloading Test time Load 10mm/min displacement speed at 0oC Loading Healing Reloading 10mm/min displacement speed at 0oC Floading Freloading % 100% reloading loading F H F =  5min, 30min and 3 hours at 20oC Unload at post-peak target elongation TEafter Test time Load 10mm/min displacement speed at 0oC Loading Healing Reloading 10mm/min displacement speed at 0oC Floading Freloading % 100% reloading loading F H F =  5min, 30min and 3 hours at 20oC Unload at post-peak target elongation TEafter

Test samples used>Before loading>Total failure160140120100Z06040200.51.52.53.524.535/15Displacement[mm]

5 | 15 Test samples used ➢Before loading ➢Total failure 0 20 40 60 80 100 120 140 160 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 Displacement [mm] Force [N]

single-crack width (SCW)TEafter1mm2mm3mm3.5mmTotallybrokenSCW10mm30mm50mm100mm

6 | 15 single-crack width (SCW) TEafter 1mm 2mm 3mm 3.5mm Totally broken SCW - 10 mm 30 mm 50 mm 100 mm

LHR test results100ANe908070X60PBmas-1mmPBmas-2mm50X-PBmas-3mm40-PBmas-3.5mmx-PBmas-totallybroken30XSBSmas-1mmSBSmas-2mm20SBSmas-3mm100SBSmas-3.5mm-x-SBSmastotallybroken011010000.010.1100Healingtimeat20degree[hours]TUDelft7/15

7 | 15 LHR test results 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 100 0.01 0.1 1 1 0 100 1000 Healing time at 20degree[hours] Healing percentage by 10mm/min strength[%] PBmas-1mm PBmas-2mm PBmas-3mm PBmas-3.5mm PBmas-totally broken SBSmas-1mm SBSmas-2mm SBSmas-3mm SBSmas-3.5mm SBSmas totally broken

LHR results cont.>Samples heal slower at a higherTEafter.>PBmas and SBSmas>AttheTEafterlessthan2mm,theSBSmashealsbettercomparedtothePBmas,evenafteronly5minutesofhealingtime.>AttheTEafterabove2mm,thePBmasstartstohealbetterthan the SBSmas.TUDelft8/15

8 | 15 LHR results cont. ➢Samples heal slower at a higher TEafter. ➢PBmas and SBSmas ➢At the TEafter less than 2mm, the SBSmas heals better compared to the PBmas, even after only 5 minutes of healing time. ➢At the TEafter above 2mm, the PBmas starts to heal better than the SBSmas

Contributions of healing at differentcrack phasesTypical healing curve100100Viscous healing componentElastic healing componeintcontributioncontribution00UncrackedSmallcrackphaseLarge crack phaseCrackphasesphaseSCW<10μm10μm<SCW<100μmSCW=0C9/15TUDelft

9 | 15 Contributions of healing at different crack phases Healing efficiency % 0 100 Uncracked phase SCW=0 Small crack phase SCW<10m Large crack phase 10m<SCW<100m Crack phases 0 100Healing contributions % Viscous healing component contribution Elastic healing component contribution Typical healing curve Healing efficiency % 0 100 Uncracked phase SCW=0 Small crack phase SCW<10m Large crack phase 10m<SCW<100m Crack phases 0 100Healing contributions % Viscous healing component contribution Elastic healing component contribution Typical healing curve

Healing Contributions>The contribution of the elastic component decreaseswith the increase of the scW, but the viscouscomponent increases>uncrackedphase(SCW=0):Undamaged,healing duetotheelasticcomponent(instantaneouselasticrecoveryanddelayedelastic recovery)>smallcrackphase(SCW=0-10micron):Healingduetoboththe elastic and theviscous components.>largecrackphase(SCW=10-100micron):Healingduetotheviscous component (viscousflowanddiffusion)2TUDelft10/15

10 | 15 Healing Contributions ➢The contribution of the elastic component decreases with the increase of the SCW, but the viscous component increases ➢uncracked phase (SCW=0): Undamaged, healing due to the elastic component (instantaneous elastic recovery and delayed elastic recovery) ➢small crack phase (SCW=0-10 micron): Healing due to both the elastic and the viscous components. ➢large crack phase (SCW=10-100 micron): Healing due to the viscous component (viscous flow and diffusion)