Replacement of Elastic Recovery (AASHTO T301) and Force Ductility (AASHTO 300) Tests by DSR-Based Tests

Transcription

1 Replacement of Elastic Recovery (AASHTO T301) and Force Ductility (AASHTO 300) Tests by DSR-Based Tests LTRC Project No. 11-2B (Emulsions) Southern Plains Transportation Center (SPTC) Project No (Binders) By N. Wasiuddin Louisiana Tech University

2 Objectives: Characterization of asphalt emulsion residues with DSR tests: Strain sweep Frequency sweep Temperature sweep Multiple Stress Creep and Recovery (MSCR) Evaluation of correlations with: Elastic recovery Force ductility

3 Why PG-Plus tests: To identify the presence of polymers and quantify its beneficial effects PG-Plus tests: Elastic Recovery Force Ductility are being used by LA DOTD Phase Angle Toughness and Tenacity, etc.

4 States that are using PG-Plus tests (Green States as prepared in Google chart)

5 Elastic Recovery Test (AASHTO T301) and Force Ductility Test (AASHTO T300) Elastic Recovery and Force Ductility molds Ductility Bath Force Ductility sample under test Elastic Recovery sample after severing

6 Elastic Recovery Measurements: Primary shape of briquette 20 cm After pulling apart Sever at the middle after 5 minutes (20- X) cm Elastic Recovery % = (20 X) * After 1 hour

7 Force Ductility Measurements: The ratio of f 2 /f 1 or f 2 at 30 cm f1 In case of two maximum points f1 In case of one maximum point f2 f2

8 Survey of Elastic Recovery Test Methods: State Modified PG Binder Modified Emulsion Asphalt California AASHTO AASHTO T51(25 c) T301(20cm&25 c) West Virginia AASHTO - T301(20cm&25 c) Kentucky AASHTO T301(10cm&25 c) AASHTO T301(10cm&4 c) New Jersey ASTM D6084(20cm&25 c) AASHTO T301(20cm&10 c) Tennessee AASHTO T301(20cm&25 c) AASHTO T301(20cm&10 c) Texas ASTM TEX-539-C(20cm&10 c) D6084(20cm&10 c) Louisiana AASHTO T301(10cm&25 c)-2016 AASHTO T301(20cm&10 c)

9 Survey of Force Ductility Test Methods (Illinois): Test SBS PG SBS PG SBS PG SBS PG SBS PG Force Ratio (f2/f1), 4⁰c, 50mm/min., 300 mm elongation, minimum

10 Survey of Force Ductility Test Methods (Louisiana): Test PG 76-22m PG 70-22m CRS-2P SS-1P PAC 15 Force Ratio (f2/f1), 4⁰c, 50mm/min., 300 mm elongation, minimum Force Ductility, 4⁰c, 50mm/sec, 300 mm elongation, kg, minimum 0.3 _ _

11 Strain (%) MSCR Test Parameters (ASTM D7405): Stress Levels of 100 and 3200 Pa, 10 Cycles, Creep Stress 1s, Recovery 9s Percent of Recovery (%) = (Ƴr / Ƴp ) x 100 Non-Recoverable Creep Compliance (Jnr) = Ƴu /ơ One Cycle of MSCR Test Ƴp peak strain Ƴr recovered strain Ƴu unrecovered strain Time (s)

12 Why MSCR test instead of PG-Plus tests: Different states apply different methods and criteria for Elastic Recovery and Force Ductility tests MSCR Test uses the same DSR device : No additional cost Easy and time saving Repeatability Less variability due to operator Small Mechanistic

13 20 Asphalt Emulsions were investigated Polymer Modified Emulsions: PME CHFRS-2P CRS-2P (E) CRS-2P (B) CMS-1P SS-1L Polymer Modified Hard Pen Base Emulsions: CSS-1HP SS-1HP Hard Pen Base Emulsions: SS-1H (B) SS-1H (U) NTSS-1HM (C) NTSS-1HM (B) NTSS-1HM (U) FOG SEAL Non Polymer Modified Non Hard Pen Base Emulsions: CRS-2 (E) CRS-2 (B) CRS-2 (U) SS-1 (E) SS-1 (B) SS-1 (U)

14 Experimental Plan Emulsions SS-1 (E) SS-1 (B) SS-1 (U) SS-1H (B) SS-1H (U) SS-1HP SS-1L CRS-2 (E) CRS-2 (B) CRS-2 (U) CRS-2P (E) CRS-2P (B) CHFRS-2P CMS-1P CSS-1HP PME NTSS-1HM (B) NTSS-1HM (C) NTSS-1HM (U) Fog Seal Strain Sweep Temp.: 52 C and 70 C Strain: 2%, 12%, 22%, 32%, 42% and 52% 3 mat samples Freq. Sweep Temp. Sweep MSCR Elastic Recovery and Force Ductility Temp.: 10 C, 25 C, 58 C and 70 C Ang. Freq.: 0.1 rad/s 100 rad/s 3 mat samples Temp.: from 52 C to 94 C at 6 C intervals Strain and Ang. Freq.: 12% and 10 rad/s 3 mat samples and 3 DSR mold samples Temp.: 10 C, 25 C, 58 C, 70 C and one equal-stiffness temperature (2.2 kpa stiffness) Stress: 0.1kPa, 3.2 kpa (0.1kPa, 0.2 kpa, 0.5 kpa and 3.2 kpa at 2.2 kpa stiffness temp.) 3 mat samples for 0.1 and 3.2 kpa and 3 mat samples 2 for 0.2 and 0.5 kpa Temp. Elastic Recovery: 10 C and 25 C Temp. Force Ductility: 4 C 2 mat Samples for Elastic Recovery and 2 mat samples for Force Ductility

15 Recovering Residue from Emulsified Asphalt: Low temperature evaporative technique (ASTM D7497) Elastic Recovery Test : 24 hours at 25⁰C forced oven + 24 hours at 60⁰C forced oven DSR-based Test : 24 hours at 25⁰C forced oven + 24 hours at 60⁰C forced oven Force Ductility Test : 6 hours at 60⁰C forced oven

16 Sample preparation for Elastic Recovery and Force Ductility Tests:

17 Sample preparation for DSR-based Tests :

18 Strain Sweep Test: Strain Sweep Test was conducted at two temperatures, 52⁰C and 70⁰C, and six strains, 2%, 12%, 22%, 32%, 42% and 52% Drop from Initial G*% = 100* (G* 2% - G* 52% )/(G* 2% ) The lower the drop, the higher the strain tolerance Indication of linearity Drop from initial G* can be used as a criteria to estimate aggregate loss in chip seals

19 Strain Sweep Test: Polymer Modified Emulsions: PME CHFRS-2P CRS-2P (E) CRS-2P (B) CMS-1P SS-1L The maximum of tolerance at 52⁰C and 70 ⁰C are 12.9% and 16.4% respectively for SS-1L The minimum of tolerance at 52⁰C and 70 ⁰C are 3.4% and 1.9% respectively for CMS-1P

20 Strain Sweep Test: Hard Pen Base Emulsions: SS-1H (B) SS-1H (U) NTSS-1HM (C) NTSS-1HM (B) NTSS-1HM (U) FOG SEAL NTSS-1HM(C), NTSS-1HM(B) and FOG SEAL could not reach 52% strain at 52⁰C The maximum of tolerance at 52⁰C and 70 ⁰C are 44.2% and 43.3% respectively for NTSS-1HM(U) and NTSS-1HM(B) The minimum of tolerance at 52⁰C and 70 ⁰C are 15% and 1.2% respectively for SS-1H(U)

21 Strain Sweep Test: Polymer Modified and Hard Pen Base Emulsions: CSS-1HP SS-1HP The maximum of tolerance at 52⁰C and 70 ⁰C are 22.5% and 7.5% respectively for CSS-1HP The minimum of tolerance at 52⁰C and 70 ⁰C are 9.6% and 3.7% respectively for SS-1HP

22 Strain Sweep Test: Non Polymer Modified and Non Hard Pen Base Emulsions: CRS-2 (U) CRS-2 (E) CRS-2 (B) SS-1 (E) SS-1 (B) SS-1 (U) The maximum of tolerance at 52⁰C and 70 ⁰C are 6.7% and 3.8% respectively for SS-(E) The minimum of tolerance at 52⁰C and 70 ⁰C are 2.7% and 0.4% respectively for CRS-2(B) and SS-1(B)

23 Strain Sweep Test: In Summary: Higher drop from initial G* or lower strain tolerance will result in increase of aggregate loss in chip seals Asphalt emulsions prepared of hard pen base asphalt have higher drop from initial G* or lower strain tolerance

24 Frequency Sweep Test: Master curve was constructed at 25⁰ C based on conducted frequency sweep tests at 10⁰C, 25⁰C, 58⁰C and 70⁰C. Master curve is used to understand the overall rheological behavior of asphalt emulsions. Master Curve

25 Master Curve: NTSS-1HM (C), NTSS- 1HM (U) and Fog Seal show high G* values in a wide range of frequencies

26 Master Curve: NTSS-1HM (B) shows high G* value in a wide range of frequencies

27 Frequency Sweep Test: In Summary: Hard Pen Base Emulsions show higher G* value and lower strain tolerance

28 Temperature Sweep Test: Temperature Sweep Test of DSR was conducted on emulsion residues from 52⁰C to 94⁰C at 6⁰C intervals. Results of Temperature Sweep Test include: Diagram of G*/Sin(δ) versus Temperature Diagram of Phase Angle(δ) versus Temperature

29 Temperature Sweep Test: G*/Sin(δ) versus Temperature CSS-1HP NTSS-1HM (B) Hard Pen Base emulsions including NTSS-1HM (B) and CSS-1HP have the higher G*/Sin δ than other emulsions.

30 Temperature Sweep Test: G*/Sin(δ) versus Temperature NTSS-1HM (U) NTSS-1HM (C). FOG SEAL Hard Pen Base emulsions such as NTSS-1HM (C), NTSS-1HM (U) and Fog Seal have the higher G*/Sin δ than other emulsions.

31 Temperature Sweep Test: Phase Angle(δ) versus Temperature When temperature increases, phase angle increases to a maximum and then decreases. the maximum phase angle of all the non-hard pen polymer modified asphalt emulsion residues fall between 75⁰ to 85⁰.

32 Temperature Sweep Test: Phase Angle(δ) versus Temperature When temperature increases, phase angle increases to a maximum and then decreases. the maximum phase angle of all the non-hard pen polymer modified asphalt emulsion residue falls between 75⁰ to 85⁰.

33 Elastic Recovery Test (AASHTO T301): Average Elastic Recovery (%) 10⁰C 25⁰C Modified Emulsions Modified Emulsions

34 MSCR Test Results: Emulsions Creep Stress 0.1 kpa Percent Recovery (MSCR) Creep Stress 3.2 kpa 10 C 25 C 58 C 70 C 10 C 25 C 58 C 70 C Polymer Modified Emulsions CMS-1P CRS-2P (B) CRS-2P (E ) SS-1L PME CHFRS-2P Polymer Modified and Hard Pen Base Asphalt Emulsions CSS-1HP SS-1HP

35 MSCR Test Results: Emulsions Creep Stress 0.1 kpa Percent Recovery (MSCR) Creep Stress 3.2 kpa 10 C 25 C 58 C 70 C 10 C 25 C 58 C 70 C Non-Polymer Modified and Non-Hard Pen Base Asphalt Emulsions SS-1 (B) SS-1 (E ) SS-1 (U) CRS-2 (U) CRS-2 (B) CRS-2 (E )

36 Emulsions MSCR Test Results: Creep Stress 0.1 kpa Percent Recovery (MSCR) Creep Stress 3.2 kpa 10 C 25 C 58 C 70 C 10 C 25 C 58 C 70 C Hard Pen Base Asphalt Emulsions SS-1H (U) SS-1H (B) NTSS-1HM (U) NTSS-1HM (C ) NTSS-1HM (B) > >100 > > >100 > >100 > FOG SEAL >100 > >

37 MSCR Test Results: Emulsions 2.2 kpa Stiffness (G*/sinδ) Temperatures C) Creep Stresses (kpa) R 2 Value for Log(stress) vs. Percent Recovery Polymer Modified Emulsions CRS-2P (E) 63 C SS-1L 61 C CHFRS-2P 67 C CMS-1P 55 C CRS-2P (B) 59 C PME 62 C Polymer Modified and Hard Pen Base Asphalt Emulsions CSS-1HP 80 C SS-1HP 66 C

38 MSCR Test: Emulsions 2.2 kpa Stiffness (G*/sinδ) Temperatures C) Creep Stresses (kpa) R 2 Value for Log(stress) vs. Percent Recovery Non-Polymer Modified and Non Hard Pen Base Asphalt Emulsions CRS-2 (U) 56 C CRS-2 (B) 57 C CRS-2 (E) 57 C SS-1 (U) 57 C SS-1 (B) 57 C SS-1 (E) 57 C

39 MSCR Test Results: Emulsions 2.2 kpa Creep Stresses (kpa) Stiffness (G*/sinδ) Temperatures C) Hard Pen Base Asphalt Emulsions R 2 Value for Log(stress) vs. Percent Recovery SS-1H (U) 68 C SS-1H (B) 68 C Fog Seal 94 C NTSS-1HM (U) 79 C NTSS-1HM (B) 96 C NTSS-1HM (C) 90 C

40 Correlation between MSCR parameters and Elastic Recovery Coefficient of Determination (R 2 ) for Linear Correlation Between Percent Recovery (MSCR) and Elastic Recovery (AASHTO T301) MSCR Temperature 58 C 70 C 2.2 kpa Stiffness Temperature MSCR Creep Stress Elastic Recovery Temperature (AASHT T301) 10 C 25 C 0.1 kpa kpa kpa kpa kpa kpa

41 Correlation between MSCR parameters and Elastic Recovery Coefficient of Determination (R 2 ) for Linear Correlation Between Non-Recoverable Creep Compliance, J nr (MSCR) and Elastic Recovery (AASHTO T301) MSCR Temperature 58 C 70 C 2.2 kpa Stiffness Temperature MSCR Creep Stress Elastic Recovery Temperature (AASHTO T301) 10 C 25 C 0.1 kpa kpa kpa kpa kpa kpa

42 Linear correlation between percent recovery (MSCR at 58 C) and elastic recovery

43 Linear correlation between percent recovery (MSCR at 2.2 kpa temperature) and elastic recovery

44 Linear correlation between percent recovery (MSCR at 70 C) and elastic recovery

45 Force Ductility Test: Emulsions Max. Force, f 1 (lb) Force at 30 cm, f 2 (lb) f 2 /f 1 Force at 35 cm (lb) Avg. St. Dev. Avg. St. Dev. Avg. St. Dev. Avg. St. Dev. Polymer Modified Emulsions CHFRS-2p CMS-1p CRS-2P (E ) PME SS-1L Non-Polymer Modified and Non-Hard Pen Base Asphalt Emulsions CRS-2 (U) CRS-2 (E ) SS-1 (U) SS-1 (B) SS-1 (E ) sample sample sample sample

46 Force Ductility Test: Emulsions Max. Force, f 1 (lb) Force at 30 cm, f 2 (lb) f 2 /f 1 Force at 35 cm (lb) Avg. St. Dev. Avg. St. Dev. Avg. St. Dev. Avg. St. Dev. Hard Pen Base Asphalt Emulsions SS-1H (U) SS-1H (B) Fog Seal sample NTSS-1HM (U) NTSS-1HM (B) Polymer Modified and Hard Pen Base Asphalt Emulsions CSS-1HP SS-1HP

47 Force Ductility Test:

48 Force Ductility Test:

49 Force Ductility Test:

50 Force Ductility Test:

51 Force Ductility Test:

52 Force Ductility Test:

53 Force Ductility Test: Force Ductility Test Parameter Linear Correlation with Phase Angle Phase Angle Testing Temperature 58 C 70 C 2.2kPa Temp. Average R 2 Force at 30 cm, f 2 (lb) f 2 /f Force at 35 cm (lb) Average R Linear Correlation with Percent Recovery Force Ductility Test Parameter Percent Recovery (at 0.1 kpa Creep Stress) Testing Temperature 58 C 70 C 2.2kPa Temp. Average R 2 Force at 30 cm, f 2 (lb) f 2 /f Force at 35 cm (lb) Average R

54 Recommendations: MSCR (ASTM D7405) has been recommended to replace Elastic Recovery test (AASHTO T301) to identify the presence of polymer. Residue should be prepared according to ASTM D7497. Test Minimum Percent Recovery, 58⁰C, 0.1 kpa creep stress Specifications 25 Minimum Percent Recovery, MSCR, 58⁰C, 3.2 kpa creep stress 9

55 Recommendations: Percent recovery of MSCR and phase angle can be used to replace force ductility requirements (AASHTO T300). Test Specifications Minimum Percent Recovery, MSCR at 58⁰C, 0.1kPa creep stress 30 & Maximum Phase angle, 58⁰C, 12% strain, 10 rad/sec 81⁰

56