The objective of this task is to develop a mix design procedure for the various types of FDR Determine what works and what does not work Each type of FDR has separate mix design
◦ Unstabilized ◦ Mechanically stabilized: add virgin aggregate ◦ Stabilized FDR with Portland Cement ◦ Stabilized FDR with Fly Ash ◦ Stabilized FDR with Asphalt Emulsion ◦ Stabilized FDR with Asphalt Emulsion with 1% Lime ◦ Stabilized FDR with Foamed Asphalt with 1% Portland Cement
◦ Source: Good and Poor ◦ Quality: Dirty and Clean ◦ RAP: 0, 25, 50, and 75%
FDR SourceGradation FDR Type UnstabilizedStabilized with PC (3, 5, 7 %) Stabilized with Fly Ash (10, 12, 15 %) Stabilized with Asphalt Emulsion (3, 4.5, 6 %) Stabilized with Asphalt Emulsion (3, 4.5, 6 %)+ Lime Stabilized with Foamed Asphalt (2.5, 3, 3.5 %) + PC Good Clean -Moisture-density -Mr and CBR -Moisture-density - Comp strength -Moisture sensitivity -Moisture-density - Comp strength -Moisture sensitivity -Moisture-Density Superpave Gyratory - Density with Corelok -Moisture sensitivity -Moisture-Density -Superpave Gyratory - Density with Corelok -Moisture sensitivity -Moisture-Density -Superpave Gyratory -Density with Corelok -Moisture sensitivity Dirty SAME Poor Clean SAME Dirty SAME
Strength: ◦ Mr and CBR for unstabilized ◦ UC for cement and fly ash stabilized ◦ TS for foamed and emulsion stabilized Moisture Susceptibility ◦ Tube Suction and ASTM D559 For cement and fly ash stabilized ◦ AASHTO T-283 for foamed and emulsion stabilized
What works and what does not What criteria to implement Repeatability and reliability Does the measurement make engineering sense
RAP 25 and 50% content did not significantly impact the Mr The 75% RAP improved the Mr of the Poor source Relationship between Mr and CBR is un- reliable for FDR: Use Mr
FDR+PC & FDR+FA ◦ Dry UC:300 – 400 psi ◦ Tube Suction:max 9 FDR+Foamed & FDR+Emulsion ◦ Dry TS at 77F:min 30 psi ◦ TS Ratio:min. 70%
Material - %Rap%PCDry UC (psi)Tube Suction GC-25% GC-50% GC-75% GD-25% GD-50% GD-75% PC-25% PC-50% PC-75% PD-25% PD-50% PD-75%
UC strength between 300 and 400 psi is achievable in most cases Higher UC with higher PC content in all cases Variability of the UC test is acceptable Tube Suction test maybe applicable
Material -% Rap%FADry UC (psi)Tube Suction GC-25% GC-50% GC-75% GD-25% GD-50% GD-75% PC-25% PC-50% PC-75% PD-25% PD-50% PD-75%
UC strength between 300 and 400 psi is achievable except for the Poor-Dirty material Higher UC with higher FA in most cases Variability of the UC is acceptable Tube Suction test maybe applicable
Material –%Rap%EmulsionDry TS(psi)Wet TS(psi)TSR (%) NO LIME GD-25% GD-50% GD-75% PD-25%4.530Disintegrate PD-50%4.550Disintegrate PD-75%4.551Disintegrate 1% LIME GD-25% GD-50% GD-75% PD-25% PD-50% PD-75%
Could not design the clean materials: too little fines The TS is a good indicator The repeatability of the TS is very good Lime was effective
Material - %Rap%ACDry TS(psi)Wet TS(psi)TSR (%) GC-25%3.0* GC-50%3.0* GC-75%3.0* GD-25% GD-50% GD-75% PC-25% PC-50% PC-75% PD-25% PD-50% PD-75%
Could not design without the PC The TS is a good indicator The repeatability of the TS is very good
Be consistent with AASHTO Design Guides ◦ AASHTO 1993 ◦ AASHTO MEPDG
Unstablised: Resilient modulus (Mr) FDR+PC & FDR+FA: Modulus of Rupture (MR) FDR+Foamed & FDR+Emuslion: Dynamic Modulus (E*)
Material - %Rap%PCDry UC (psi)MR (psi) GC-25% GC-50% GC-75% GD-25% GD-50% GD-75% PC-25% PC-50% PC-75% PD-25% PD-50% PD-75%540979
Material - %Rap%FADry UC (psi)MR (psi) GC-25%Rap GC-50%Rap GC-75%Rap GD-25%Rap GD-50%Rap GD-75%Rap PC-25%Rap10558 PC-50%Rap PC-75%Rap12327 PD-25%Rap PD-50%Rap PD-75%Rap156348
|E*| master curve: Modulus of HMA at any combination of loading rate & temperature. Time Stress Strain Time time shift = / = 0 sin(ωt) = 0 sin(ωt- ) 00 00 |E*| = σ 0 /ε 0 34