October 2018 KDOT ASPHALT UPDATE Continue with bond testing 339 miles for FY 2019 as of December letting Intent establish a tack procedure that produces a good bond tack coat quality ID: 759826
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Slide1
Blair Heptig
KAPA/KDOT Fall ForumOctober 2018
KDOT ASPHALT UPDATE
Slide2Continue with bond testing339 miles for FY 2019 as of December lettingIntent – establish a tack procedure that produces a good bond (tack coat quality)
Fiscal YearCenterline Miles with Bond Test201834720173452016802015399201455920132912012189201167
BOND TEST
Slide3New products/approved alternates on bond test projectsCBC-1HT (eTac) from ErgonOthers?Spray paverUse when overlaying PCCP or UBAS67 centerline miles in FY 2018
TACK
Slide4CORES
Bond test special provision revisedStart paying for bond test coresNew Engineer determines testing frequency“Bond Core” bid item, $90 set price for each 6” core
Slide5CORES
Section 602 special provision revisedPay for density dispute cores Decreased from 1.5 times the price of calibration cores (1.5 x $45 = $67.50) to 1 times the price (1 x $45 = $45)Concerns from Construction – documentation issuesDidn’t want to make a dispute core bid item at this time
Slide6SURFACE QUALITY
Section 602 special provisionConsidered changing requirement for minimum number of rollers from 2 minimum @ 275 tph to 2 minimum @ 250 tphNo change at this time – continue to monitor
Slide7Overlay bumpsProfilograph uses a minimum scallop length of 2 ftKDOT to check with straight edge“Tears” or roller marks/cracksTexture issues
SURFACE QUALITY
Slide8RCI
Section 614 special provision revisedChanged target air voids in design from 4.5% to a range of 4.5% – 5.0% Target remains 4.5% during productionMinimize aggregate blend changes
Slide9Increase of minimum VMA requirement0.1% for every 1% RAS used in the mixHandled on project by project basis – Modified RequirementsMay not use on some high volume 3% air voids projects or SR-9.5A mixes with 3% air voids
RAS
Slide10RAS
Working with KAPA on developing requirements to weigh RAS at the plantCurrently control RAP/RAS proportions by calibrationAssess variability in feed and weightsGoal is to implement in FY 2020Likely weigh depletion (load cells) or weigh bridge
Slide11MIX DESIGN
1,681,847 total tons of HMA let in FY 2018
Commercial grade = 79,637 tons
UBAS = 59,485 tons
RCI = 21,093 tons
4% air voids = 723,314 tons
3% air voids = 798,318 tons (47%)
Higher percentage of 3% air voids projects in FY 2019
FY 2019 EFT trial projects in District 2
Slide12MIX DESIGN
NCHRP Report 567
3%
Va
, 94% density
4%
Va
, 93%
density
Slide13Why not on 4% air voids projects?Targets may not be achievableConsiderationsRoad structureFWD dataDistress dataActionAction historyAngularity?%Gmm at Nini?Gyratory revolutions?RAP?
INCREASED IN-PLACE DENSITY
Slide14INCREASED IN-PLACE DENSITY
2017K-25 Logan County7/75/115 rev40% max RAPNo SSG limitRelax FAA and %Gmm @ Nini (92.0%)
2018
US-77 Geary County
7/75/115 rev
15% max RAP
K-27 Wallace County
Both lifts (12.5A and 19A)
7/75/115 rev
25% max RAP
Slide15INCREASED IN-PLACE DENSITY
2019K-9 Phillips Co. & Smith Co.Surface lift only (not 19A)7/75/115 rev40% max RAPNo SSG limitRelax FAA and %Gmm @ Nini (92.0%)I-70 Thomas Co.Both lifts (12.5A) 8/100/160 rev25% max RAPRelax %Gmm @ Nini (91.5%)
2019
US-24 Cloud Co.
Surface lift only (not base 12.5A)
7/75/115 rev
20% max RAP
US-283 in Trego Co. and Graham Co.
Surface lift only (not 19A)
7/75/115 rev
40% MAX RAP
Slide16ASPHALT BINDERS
Recycling agents (rejuvenators)Used in several shoulder mixesMonitoring mainline mixes2014 project on US-160 in Labette Co. & Montgomery Co.2015 project on K-232 in Lincoln Co. & Ellsworth Co.2018 project K-57, K-244 and K-244S in Geary County2019 projectsShoulder mix on US-81 in Republic Co.Mainline mix on K-266 in Republic Co.Evoflex, Hydrogreen and Delta S options
Slide17ASPHALT BINDERS
REOBs (re-refined engine oil bottoms)FHWA checked binder prequalification samples using X-ray fluorescence spectroscopy (XRF) No REOBs detectedDeveloping protocol to check for REOBsAsh testΔTc – after 20 hr PAV and after 40 hr PAVXRF – trial tests being performed at KSU
Slide18PERFORMANCE TESTING
Collecting data on field produced mixes
Goal – assess how mix properties affect performance
Volumetrics
Aggregate properties
Compaction
Recycled materials
Binder grades
Additives
Potentially modify “recipe” based on the results
Can equivalent mix be produced for lower price?
Can durability be improved for the same or similar price?
Slide19TOOLBOX
Surface treatments Mastic surface treatment (Onyx)Centerline rumble strip sealProducts – mastic, tack, rejuvenator, rejuvenating emulsion, striping material Scrub seal
Slide20QUESTIONS?
Thank you!