2018 Pavement Workshop Flexible Session May 23 24

2018 Pavement Workshop Flexible Session May 23 -24, 2018 Tensile Strength Ratio (AASHTO T 283) Testing Brett Trautman, PE Physical Laboratory Director Construction and Materials Division Missouri DOT + 46 Associate Members 1

History in Missouri § Been performing on field samples for over 15 years - Allows contractors options (hydrated lime, antistrips, etc…) - Samples taken at the asphalt plant - Material retain for dispute resolution purposes § Sampling Frequency - QC: 1 sample per 10, 000 tons - QA: 1 sample per 50, 000 tons

History in Missouri § Incentive/Disincentive pay factors - Price adjustment based on QC data - Need favorable comparison between QA and QC test results § The following pay adjustment table used:

Molding Process § Samples received at the Central Laboratory § Bucket place into oven set at 5 deg. C below the molding temperature - Achieve a workable mix - Max. time limit of 2 hours § Weigh out material for molding specimens - Use quartering method

Molding Process § Samples then placed into an oven set at the molding temperature - Max. time limit of 2 hours § Samples compacted to 95 mm - Achieve 7. 0 +/- 0. 5% air voids § Trial specimen molded to verify the mix weight is correct - Prevent wasting material

Mix Designs TYPE AGG SIZE BINDER DES VOIDS MODIFIED NDES SPWEB 340 C 12. 5 58 H-34 4. 0 0 SPWED 440 E 4. 8 58 H-28 4. 0 0 SPWEA 440 E 9. 5 58 H-28 4. 0 0 SPWEB 450 E 12. 5 58 H-28 5. 0 50 SPWEB 440 E 12. 5 58 H-28 4. 0 0 SPWEC 440 E 19. 0 58 H-28 4. 0 0 SPWEB 430 E 12. 5 58 H-28 3. 0 0 SPWED 430 I 4. 8 58 E-34 2. 0 -3. 0 50 UTBWC - - - 0

EA 44 0 E SP W EB 34 0 C SP W EB 43 0 E SP W EB 44 0 E SP W EB 45 0 E SP W EC 44 0 E SP W ED 43 SP 0 I W ED 44 0 E U TB W C W SP No. of Gyrations Average No. of Gyrations 60 50 30 20 50 40 34 26 33 24 25 20 16 Mixtures 12 10 0

Average Air Voids 12 Wet Set Air Voids, % 11 10. 8 10. 9 Dry Set 10 9 8 7 6. 8 7. 2 7. 4 7. 1 7. 2 7. 0 7. 2 6. 9 7. 0 6. 8 6. 9 6 SP W EA 44 SP 0 E W EB 34 SP 0 C W EB 43 SP 0 E W EB 44 SP 0 E W EB 45 SP 0 E W EC 44 0 E SP W ED 43 SP 0 I W ED 44 0 E U TB W C 5 Mixtures

EA 44 SP 0 E W EB 34 SP 0 C W EB 43 SP 0 E W EB 44 SP 0 E W EB 45 SP 0 E W EC 44 0 E SP W ED 43 SP 0 I W ED 44 0 E U TB W C SP W Saturation, % Average Saturation (Conditioned Set) 85 80 78 79 78 Mixtures 80 78 77 75 72 70

W EA 44 SP 0 E W EB 34 0 C SP W EB 43 0 E SP W EB 44 0 E SP W EB 45 SP 0 E W EC 44 0 E SP W ED 43 SP 0 I W ED 44 0 E U TB W C SP Tensile Strength Ratio (TSR) 110% 100% 99% 98% 95% 90% Mixtures 96% 94% 91% 85% 80% 71% 70% 60%

EB 34 0 C SP W EB 43 0 E SP W EB 44 0 E SP W EB 45 0 E SP W EC 44 0 E SP W ED 43 SP 0 I W ED 44 0 E U TB W C SP W EA 44 0 E W SP Tensile Strength, lbs. /in. 2 Conditioned and Unconditioned Tensile Strengths 120 110 100 90 80 70 60 50 40 30 Conditioned Unconditioned Mixtures

Questions