OGFC Test Sections. Structural Study - Group Experiment. Data Collection. Complimentary Sections. SEAUPG - SAVANNAH, GEORGIA November 16, 2011

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1 SEAUPG - SAVANNAH, GEORGIA November, 9 Test Sections Structurl Chrcteriztion of nd % RAP/WMA Sections Florid Albm Thiopve Krton Oklhom RAP RAP-WMA Control WMA-F WMA-Add. N N N N N N N7 N8 N9 N N S S S TLA-% 8 November, r. vid Timm, P.E. eprtment of Civil Engineering Thickness, in. 8 Albm Florid North Crolin South Crolin Tennessee FHWA PG 7- PG 7- Krton PG 7-8 (SMA) PG 7-8 % Thiopve PG - PG - (% Air Voids) % Thiopve Limerock Bse Grnite Bse Trck Soil Sele Subgrde Structurl Study - Group Experiment Sponsors AL, FL, NC, OK, SC, TN, FHWA Six Sections Control section % RAP % RAP / WMA (fom) Wrm Mix Technology A (fom) Wrm Mix Technology B (dditive) Control with surfce t Collection High Speed Weekly psses of ech truck on ech section Slow Speed reding/minute Hourly summry Performnce Weekly Rut depth Crcking FW times/month Complimentry Sections Krton Highly polymer modified mteril Thinner cross section thn control Shell Thiopve Two thicknesses Mtch control nd mtch pre-existing section Trinidd Lke Asphlt Pellets used s dditive to stiffen mixture Advntges Sfety Improved dringe, reduced splsh/spry Lower noise to db reduction Concerns Structurl contributions? Structurl coefficient? Use in M E design? Video courtesy of Buzz Powell

2 SEAUPG - SAVANNAH, GEORGIA November, Test Sections SN eff nd epth Below Surfce, in Control 9. mm PG 7-9 mm PG 7-9 mm PG 7- Crushed Aggregte Bse Averge SN eff..... control control surfce ΔSN.*.... ΔSN... eflection Testing Methodology Follow AASHTO procedure for overly design Find effective structurl number (SN eff ) Compre SN to SN Attribute differences to lyer Bckclculte structurl coefficient of Equivlent Thickness using. 7.8 in.. in.. SN.9 7 in.. SN.78 SN.78.. in. SN.9 P AC δ Aggregte Bse Subgrde Compute M R, E p nd SN eff r δ r δ.* p * SN eff M R. * P M R δ * r r + E p + M R + E p.* * E p Modulus nd Strin Chrcteriztion Bckclculte lyer properties Normlize modulus to 8F Exmine strin response Normlize to 8F etermine equivlent structure to chieve equivlent strin

3 SEAUPG - SAVANNAH, GEORGIA November, Bckclculted Modulus vs Temperture Strin t 8F nd 7 Totl Thickness How much dditionl thickness does need to hve sme strin level s t 8F? Bckclculted AC Modulus, ksi 9.e -.*T R.9 9.8e -.8*T R.9 Reference Temperture 8F Averge Longitudinl Microstrin t 8F 8 Mid-epth Pvement Temperture, F AC Modulus t 8F Equivlent Thickness etermintion t 7 Normlized Bckclculted AC Modulus, ksi 79 9 Estimted Microstrin Level. in in... in. depth to chieve strin level Totl AC epth ( + AC), in. Strin vs Temperture Rutting Longitudinl Microstrin Under Single Axles e.8*T R.89.8e.*T R.89 8 Mid-epth Temperture, F Control Rutting

4 SEAUPG - SAVANNAH, GEORGIA November, RAP/WMA Bckground WMA nd RAP re green technologies Much longer experience with RAP thn WMA Interest in higher RAP percentges Combintion of RAP nd WMA is reltively new Extensive lb studies hve been conducted Ftigue properties not ffected by WMA Generlly poorer ftigue performnce from RAP Limited full scle structurl evlutions Section -Lift Mixing Temperture ( F) WMA Technology Mix Properties % RAP NMAS Virgin Binder PG Effective AC (%) Air Voids (%) N N- None N N N- 7 Astec BG N None % RAP Sections Mix esign 8 gyrtions % ir voids Grnite nd limestone virgin ggregtes RAP mixtures hd % frctionted RAP Surfce mixture: % fine & % corse RAP Binder nd Bse mixtures: % fine & % corse Longitudinl Strin vs Temperture As Built Thicknesses Normlized F & 7 N-RAP-HMA N-RAP-WMA -Control epth from Surfce, in. No sttisticl differences between sections (α.) Averge Stndrd evition 7 8 Surfce Lift Intermedite Lift Bottom Lift

5 SEAUPG - SAVANNAH, GEORGIA November, Normlized 8F & 7 Normlized F All differences between sections significnt (α.) No sttisticl differences between RAP sections (α.) Control is sttisticlly higher thn RAP sections (α.) % 9% 8% % Averge Stndrd evition Normlized F & 7 No sttisticl differences between RAP sections (α.) Control is sttisticlly higher thn RAP sections (α.) Normlized 8F % % All differences between sections significnt (α.) % 7% AC Modulus vs Temperture Normlized F All differences between sections significnt (α.) % %

6 SEAUPG - SAVANNAH, GEORGIA November, Rutting Performnce Control % RAP % RAP WMA Summry All sections hve performed very well fter million ESAL Recommended structurl coefficient. Computed by AASHTO method Verified through strin mesurement % RAP sections hve equl or better performnce thn control No crcking Minor rutting ifferences in RAP response is greter t higher tempertures Strin No difference in strin t low temps At higher tempertures, strin decrese by up to % AC Modulus All differences were significnt (Control<RAP WMA<RAP) ifferences incresed with temperture (9 %)