DUPONT ELVALOY RESEARCH REPORT STUDY OF PMA BINDERS & MIXES USING CITGO ASPHALT

Transcription

1 INTRODUCTION A study was undertaken using a Citgo Savannah and a limestone aggregate to investigate the impact 4 different polymer additives on both the binder and on mixes produced from those binders. Figure 1 summarizes the polymer additives used in this study. Through the use of a TAInstruments AR-2 rheometer with special software to perform repeated creep and recovery tests on binders, we were able characterize and compare the modified binders for this study. The repeated creep and recovery test has been proposed as a new protocol 1 to better predict binder performance in mixes with respect to permanent deformation. In addition, using the AR-2, we were able to develop a torsional creep stress test which we performed on slices of each mixture. The failure profile of each specimen is similar to that of simple performance tests proposed by Witczak 2. By allowing the mixture specimens to strain until failure, we were able to compare the relative performance capabilities of each mixture. We found that binder elasticity as measured by either cumulative strain or phase angle is strongly correlated to mixture resistance to creep failure. Furthermore we were able to arrive at a recommendation for a phase angle value that appears (for these mixes made with these binders) to be related to a superior level of mixture performance. 1 Bahia, et. al NCHRP report 459 P. 53 and following, published 21 2 Witczak, M.W.; Bonaquist, R; Von Quintus, H; and Kaloush, K; Specimen Geometry and Aggregate Size Effects in Uniaxial Compression and Constant Height Shear Tests, Association of Asphalt Paving Technolgists, 2, Vol 69, Page 1

2 FIGURE 1 AN INVESTIGATION INTO THE CUMULATIVE STRAIN PROPERTIES OF CITGO CONTAINING 4 DIFFERENT POLYMERS. A FURTHER INVESTIGATION INTO THE RESISTANCE TO PERMANENT DEFORMATION OF HMA MIXES PRODUCED FROM THESE POLYMER BLENDS MATERIALS INVESTIGATED CITGO BASE SBS NON CROSS LINKED SBS CROSS LINKED ELVALOY RET (REACTIVE ETHYLENE TERPOLYMER) ETHYLENE VINYL ACETATE (EVA) Page 2

3 FIGURE 2 BINDER SAMPLE LOADED INTO RHEOMETER FOR REPEATED CREEP AND RECOVERY TEST TO DETERE CUMULATIVE STRAIN OF BINDER. NCHRP report 459 (pp. C.IV.1-C.IV.4) outlines the test method. We used a 25 mm test specimen, 1 mm thickness, 3 Pa of Stress and applied 1 cycles of a 1 second period of stress application followed by a 9 second period of zero stress per cycle. Page 3

4 FIGURE 3 CITGO (GA),, 67 C, 3 PA, CUM CRT FROM TOP DOWN BASE SBS ELVAX SBS CROSSLINKED ELVALOY 5. % strain global time (s) 165 CUMULATIVE STRAIN OF BINDERS USED IN THIS STUDY. The repeated creep test was performed at 67 C & 3 Pa of stress using a 1 second stress application and a 9 second period of zero stress. The results shown here are the strains at the end of 1 cycles. As can be seen from these results, all polymer additives considerably reduce the total accumulated strain of the binder. Page 4

5 FIGURE 4 CITGO (GA), PMA BLENDS, 67 C, 3 PA, CUM CRT FROM TOP DOWN SBS ELVAX SBS CROSSLINKED ELVALOY 8. % strain global time (s) 16 CUMULATIVE STRAIN OF JUST THE POLYMER MODIFIED BINDERS. These results show that there is a difference in accumulated strain based on the different polymer additives. Page 5

6 FIGURE 5 PMA BLENDS WITH CITGO (GA),, 67 C, 3 PA, CUM CRT FROM TOP DOWN SBS ELVAX SBS CROSSLINKED ELVALOY 8. % strain global time (s) 165 SAME RESULTS FROM PREVIOUS FIGURE WITH BROADER LINES TO MAKE CUMULATIVE STRAIN RESULTS EASIER TO OBSERVE. Page 6

7 FIGURE 6 PMA BLENDS WITHCITGO (GA),, 67 C, 3 PA, CYCLE FROM TOP DOWN SBS SBS CROSSLINKED ELVAX ELVALOY % strain global time (s) 61. CYCLE 1 OF CREEP RECOVERY TEST FOR THE POLYMER MODIFIED BINDERS. The upwards rising portion of the test cycle results from the 1 second stress application. During the 9 seconds of zero stress the binder is allowed to recover some of the strain that was caused by the stress application. The more elastic the binder at the test temperature the more of the strain imparted will be recovered. Page 7

8 FIGURE 7 MIX SLICE MOUNTED IN AR-2 RHEOMETER IN PREPARATION FOR STATIC CREEP TESTING. Specimens typically measure 5 mm in length, 12 mm in width and 6.3 mm in thickness. The test consists of a constant torsional stress being applied until the specimen strain reaches 12%. At 12% strain the specimen will have generally reached the tertiary flow region shown on the previous plot. Page 8

9 FIGURE 8 EXAMPLE OF SPECIMENS WHICH HAVE BEEN TESTED TO FAILURE USING A STATIC CREEP TEST AS PERFORMED IN THE AR-2. Page 9

10 FIGURE TYPICAL FLOW TIME FAILURE CURVE TERTIARY FLOW % strain SECONDARY FLOW REGION FAIURE REGION PRIMARY FLOW 2. REGION OF PLASTIC FLOW OF MIX global time (s) 175 TYPICAL RESULTS OF A STATIC CREEP TEST PERFORMED ON A MIXTURE SPECIMEN USING A DYNAMIC SHEAR RHEOMETER. During this test a specimen (see Figure 11) is tested using a constant torsional stress and resulting strain is monitored. As the plot in the figure shows, there is an initial period of rapid strain development (Primary flow) followed by a period of when the strain increases at a linear rate (Secondary flow), and lastly the specimen begins to fail as the rate of change of strain increases quite rapidly (Tertiary flow). See Witczak s paper referenced in footnote 2 for more detailed discussion of this type of mix failure profile. Page 1

11 FIGURE 1 CITGO (GA) 64-22, CONTROL, THICK, 1, 5,PA, 67 C, CRT 12. CONTROL ELVAX SBS BLEND SBS CROSSLINKED 1. ELVALOY % strain CITGO (GA) 64-22, CONTROL, THICK, 1, 5,PA, 67 C, CRT-1c SBS CROSSLINKED, CITGO (GA) 76-22, 5d IDT, THICK, 1, 5,PA, 67 C, CRT-1c DH115B SBS CITGO (GA) 76-22, 5d IDT, THICK, 1, 5,PA, 67 C, CRT-4c DH115A ELVAX 15W CITGO (GA) 76-22, 5d IDT, THICK, 1, 5,PA, 67 C, CRT-3c DH114A ELVALOY CITGO (GA) 76-22, 5d IDT, THICK, 1, 5,PA, 67 C, CRT-2c global time (s) 7. STATIC CREEP TEST RESULTS FOR EACH OF THE MIXES MADE WITH THE BINDERS INDICATED. The creep test has been described earlier and as can be seen the shapes of the failure curves correspond to the typical curve described in the previous Figure. All specimens were cut from gyratory pills that had been aged for 5 days at 85 C. The mix tests were conducted at 67 C with a constant stress application of 5, Pa until the specimens had reached a strain of 12%. For this test summarization the more creep resistant mixes require a longer test time to fail. Page 11

12 FIGURE 11 CUMULATIVE STRAIN %, RESIDUE 67 C 1E Log1(Y) = X EMS = R 2 =.95 ELVALOY SBS X-LINK SBS EVA CONTROL PHASE ANGLE AT G*/SIN(d) AT 67 C 4/23/1 18:49:3 C:\PlotITW\MIX AND BINDER CREEP\CITGO CUMULATIVE STRAIN AS FUNCTION OF PHASE ANGLE.spf CORRELATION OF THE CUMULATIVE STRAIN OF THE RESIDUE TO THE PHASE ANGLE OF THE BINDER OBTAINED FROM THE TEST ON THE RESIDUE. The cumulative strain of the binder decreases as the phase angle decreases. The EVA binder does not follow the relationship as exactly as do the elastic binders. However, the EVA binder with a 7 degree phase angle has a cumulative strain that is below the functional line defined by the other binders. Page 12

13 FIGURE 12 TORSIONAL FLOW TIME OF MIX AT 67 C ELVALOY FLOW TIME FAILURE AT 67 C, 5, Pa STRESS CORRELATED TO PHASE ANGLE OF BINDER RESIDUE SBS X-LINK SBS EVA UPPER LEFT HAND CORNER IS BETTER MATERIAL LONGEST TIME TO MIX FAILURE RELATED TO LOWEST PHASE ANGLE Log1(Y) = X EMS = R 2 =.991 CONTROL PHASE ANGLE RESIDUE, 1 RAD/SEC, 67 C 4/26/1 1:8:34 C:\PlotITW\MIX AND BINDER CREEP\CITGO TORSIONAL FLOW TIME AS FUNCTION OF PHASE ANGLE.spf FUNCTIONAL RELATIONSHIP BETWEEN FLOW TIME FAILURE OF THE MIX SAMPLES AND THE PHASE ANGLE OF THE BINDERS USED TO PRODUCE THE MIXES. This relationship is quite precise and shows that for all the binders the lower the phase angle of the binder used the make the mix the longer it takes for the mix to fail in the creep test. The longer it takes for the mix to fail in the creep test, the more resistant to permanent deformation the mix should be in service. Page 13

14 FIGURE 13 1E+4 5 CORRELATION OF η OF BINDERS TO PHASE ANGLE CITGO POLYMER MODIFIED BINDERS Log1(Y) = X EMS = R 2 =.913 η OF CYCLE 67 C 1 5 ELVALOY SBS X-LINK SBS EVA CONTROL PHASE 67 C 4/26/1 1:1:48 C:\PlotITW\MIX AND BINDER CREEP\CITGO CORRELATION OF ETA ZERO OF BINDERS TO PHASE ANGLE.spf FUNCTIONAL RELATIONSHIP OF THE ZERO SHEAR VISCOSITY OF THE BINDER AT CYCLE 1 TO THE PHASE ANGLE OF THE BINDER. The zero shear viscosity of the mix is functionally related to the binder phase angle. Lower phase angles are strongly correlated to the high zero shear viscosities. Page 14

15 FIGURE DH114A, Citgo 7-22 (GA),.8% 417,.5% SPA,, 67 C, 3 PA, CUM CRT % strain Discrete retardation spectrum J: E-3 m^2/n n: 2719 Pa.s J1: E-4 m^2/n t1:.2365 s J2: E-7 m^2/n t2: 8.51E-3 s J3: E-6 m^2/n t3:.4583 s J4: 2.26E-5 m^2/n t4:.2386 s J5: 1.768E-9 m^2/n t5:.2214 s J6: 8.947E-6 m^2/n t6:.238 s Je: 1.63E-4 m^2/n standard error:.7788 End condition: Max. iterations exceeded Zero shear viscosity = 2719 Pa*s global time (s) 111 PLOT SHOWING AN EXAMPLE OF A SINGLE CREEP RECOVERY CYCLE OF THE BINDER. Also shown is the calculation of the zero shear viscosity based on the stress portion of the test cycle. Page 15

16 FIGURE 15 TORSIONAL FLOW TIME OF MIX AT 67 C FLOW TIME TO FAILURE CORRELATED TO SHRP STIFFNESS Log1(Y) = Log1(X) EMS = R 2 =.619 LACK OF CORRELATION BETWEEN SHRP STIFFNESS AND MIX FAILURE TIME CONTROL SBS X-LINK ELVALOY G*/SIN(d) OF 67 C SBS EVA 4/24/1 9:7:56 C:\PlotITW\MIX AND BINDER CREEP\CITGO TORSIONAL FLOW TIME AS FUNCITON SHRP STIFFNESS.spf CORRELATION OF THE TORSIONAL FLOWTIME OF THE MIX TO THE SHRP TEST PROPERTY OF EACH BINDER. Since all of the binders were manufactured to a PG grade of 76, it is reasonable that the 1 radians/sec of the residues of the modified binders should be very similar. It is easy to see from this data that there is a low correlation between the test property and the Torsional Flowtime of the mix. Page 16

17 FIGURE 16 1 CORRELATION BETWEEN MIX FLOW TIME TO FAILURE AND THE CUMULATIVE % STRAIN OF THE BINDER TORSINAL FLOW TIME, 5 KPa, 67 C ELVALOY SBS X-LINK SBS EVA Log1(Y) = Log1(X) EMS = R 2 =.93 UPPER LEFT IS REGION OF BETTER PERFORMANCE LONG TIMES TO MIX FAILURE CORRELATED TO TOTAL CREEP STRAIN OF BINDER CONTROL E+4 BINDER CUMULATIVE STRAIN, 3 Pa, 67 C, 4/24/1 9:14:27 C:\PlotITW\MIX AND BINDER CREEP\CITGO, LOG CREEP STRAIN VS FLOW TIME 3 Pa STRESS.spf TORSIONAL FLOWTIME TO FAILURE OF THE MIXES AS A FUNCTION OF THE CUMULATIVE STRAIN OF THE BINDERS. The lower the cumulative strain of the binders the longer it takes for the mix specimens to fail during the static creep test. In this relationship the EVA once again does not fit the functional relationship as closely as do the elastomeric binders. However, based on the cumulative strain of the EVA binder, the mix produced from it should have required a longer time to creep failure. Therefore, from this data, I conclude that the improvement that an EVA might impart to a binder does not translate into the same amount of improvement in mix performance. Note that for the other, elastomeric modifiers there is a direct relationship between the cumulative strain of the binder and the creep behavior of the mix. For this plot the Evlaoy modified binder had the lowest binder cumulative strain and the highest time to failure of the mix made from the modified binder. Page 17

18 MasterCurve CITGO HZ.1% STRAIN 1 1 G* MasterCurve CITGO HZ.1% STRAIN MasterCurve DH115B KRATON + BUTAPHALT IN CITGO BASE 1-115B, CITGO (GA) 76-22, 5d IDT, THICK, I, STEP TEMP, ARES (SeqTest 1) MasterCurve PG #1 114A ELVALOY USING CITGO BASE MasterCurve CITGOFLEX PG 76-22, 1 HZ,.1%STRAIN G* ( ) [Pa] ( ) [ ] Temp [ C] 9. 2.

19 FIGURE 17 7 CORRELATION BETWEEN MIX FLOW TIME TO FAILURE AND THE CUMULATIVE % STRAIN OF THE BINDER Y= 965 * (X^(-.4193)) + (-227.7) TORSIONAL FLOW TIME, 5 KPa, 67 C ELVALOY 6 5 4SBS X-LINK 3 2 EVA 1 SBS INTESECTION OF TANGENTS OCCURS AT % STRAIN WHICH CALCULATES TO A SEC FLOW TIME CONTROL BINDER CUMULATIVE STRAIN, 3 Pa, 67 C, 1/14/1 22:46:17 C:\PlotITW\MIX AND BINDER CREEP\CITGO NONLIN FIT OF CREEP STRAIN VS FLOW TIME 3 Pa STRESS.spf NONLINEAR FUNCTIONAL RELATIONSHIP BETWEEN TORSIONAL FLOW TIME AND CUMULATIVE STRAIN OF THE BINDER. A tangent is drawn from the terminal ends of the nonlinear plot. The intersection of the two tangents occurs at a binder cumulative strain of % strain. Using the nonlinear function this % strain calculates to a torsional flowtime value of seconds. It is my thought that through this analysis it may be possible to determine a minimal phase angle of the binder that can be related to mix performance. Page 18

20 FIGURE 18 FLOW TIME FAILURE AT 67 C, 5, Pa STRESS CORRELATED TO PHASE ANGLE OF BINDER RESIDUE 7 Y= 2.832e+13 * (X^(-6.26)) + (-55.22) TORSIONAL FLOW TIME OF MIX AT 67 C ELVALOY SBS X-LINK SBS A 25 SEC FLOW TIME PLOTS TO A 66 PHASE ANGLE AND THE INTERSECTION OF TANGENTS OCCURS AT A 65.6 PHASE ANGLE EVA CONTROL PHASE ANGLE RESIDUE, 1 RAD/SEC, 67 C 1/9/1 1:11:16 C:\PlotITW\MIX AND BINDER CREEP\CITGO NONLIN FIT TORSIONAL FLOW TIME AS FUNCTION OF PHASE ANGLE.spf NONLINEAR FUNCTIONAL RELATIONSHIP BETWEEN TORSIONAL FLOWTIME OF THE MIX TO THE PHASE ANGLES OF THE RESIDUE OF THE BINDERS USED IN THE MIXES. A 25 second flowtime value (as determined from Figure 17) when plotted on the curve equals a phase angle of 66 degrees. Based on this analysis a case could be made that a phase angle of 66 degrees or less is related to mixes which are resistant to permanent deformation. Using an alternative approach, a tangent is drawn from terminal ends of the nonlinear plot. The intersection of those 2 tangents occurs at a phase angle of 65.6 degrees. Since these 2 values are very similar, a phase angle of 66 degrees is a good choice as the critical phase angle based on this method of analysis. By critical phase angle I am referring to a binder phase angle that can be related to improved resistance to permanent deformation of mixes made from those binders Page 19

21 FIGURE 19 FLOW TIME FAILURE AT 67 C, 5, Pa STRESS CORRELATED TO PHASE ANGLE OF BINDER RESIDUE 7 Y= 2.832e+13 * (X^(-6.26)) + (-55.22) TORSIONAL FLOW TIME OF MIX AT 67 C ELVALOY SBS X-LINK Coefficient of Determination :.9856 Fitted Equation: Y= 2.832e+13 * (X^(-6.26)) + (-55.22) SBS EVA CONTROL PHASE ANGLE RESIDUE, 1 RAD/SEC, 67 C 1/14/1 21:47:15 C:\PlotITW\MIX AND BINDER CREEP\CITGO NONLIN FIT TORSIONAL FLOW TIME AS FUNCTION OF PHASE ANGLE.spf NONLINEAR FUNCTIONAL RELATIONSHIP OF TORSIONAL FLOWTIME TO FAILURE OF THE MIXES TO THE PHASE ANGLES OF THE RESIDUES. Although the analysis from the previous 2 Figures provided a binder phase angle value that could be related to mix performance, an alternative analysis of the nonlinear relationship shown above should also be able to provide a binder phase angle value related to mix performance. It would be worthwhile to determine how similar these predicted phase angle values are. The plan for this second analysis is to utilize the nonlinear functional relationship, determine the plot of the first derivative of this function and then from that first derivative plot determine a phase angle value that is related to significant change in the calculated slope of the function shown above. Page 2

22 FIGURE 2 PLOT OF FIRST DERIVATIVE VS. PHASE ANGLE TO DETERE A TARGET PHASE ANGLE THAT CAN BE RELATED TO MIX PERFORMANCE FOR CITGO MIXES VALUE OF FIRST DERIVATIVE AT PHASE ANGLE PHASE ANGLE OF 7-71 IS THE POINT AT WHICH THE 1ST DERIVATIVE LINE BEGINS TO DECREASE FIRST DERIVATIVE = ( *1^14)*(X^(-7.26)) PLOT OF FIRST DERIVATIVE OF NON LIN FIT OF FLOW TIME VS. PHASE ANGLE NONLIN FIT IS Y= 2.832e+13 * (X^(-6.26)) + (-55.22) 1ST DERIVATIVE IS Y= ( *1^14)*(X^(-7.26)) PHASE ANGLES OF BINDERS USED IN MIXES 1/11/1 15:28:1 C:\PlotITW\MIX AND BINDER CREEP\CITGO 1ST DERIVATIVE OF FLOWTIME VS PHASE ANGLE.spf FIRST DERIVATIVE PLOT OF NONLINEAR FUNCTIONAL RELATIONSHIP FROM FIGURE 19. At a phase angle value of approximately 72 degrees the first derivative plot (actually the slope of the function from the plot in Figure 19) begins to deviate noticeably from a straight line. This is also the value where the slope of the nonlinear function from Figure 19 begins to increase rapidly. Based on this analysis for this data set a phase angle value of 72 degrees or less for the binder residue should be required for mixes that one would expect to be resistant to permanent deformation. From the earlier analysis we arrived at a critical phase angle of 66 degrees and from this analysis a phase angle of 72 degrees. While these are similar that are not identical. This is to be expected based on the varied methods of analysis. A reasonable choice would be the average of these two approaches, which results in a critical phase angle of 69 degrees or less for a binder that one should expect will produce a mixture resistant to permanent deformation. Page 21

23 REPORT SUMMARY In this report a single limestone aggregate was used to produce mixes with 5 different binders. The 5 binders were a Citgo Savannah and 4 PG modified binders made from the PG base. The 4 modifiers used were an EVA, a SBS without crosslinking, a SBS that was crosslinked, and Elvaloy 417. Different levels of polymer were used for each additive, but in all instances a PG was manufactured. A major goal of this study was to investigate the impact of the different modifiers on the newly developed cumulative strain test for PG binders. This test is emerging as an alternative to conventional testing at 1 radians/sec because it is able to differentiate the presence of polymer modification in a binder by measuring the amount of strain that a binder will accumulate during a 1 cycle test of repeated stress applications. In general any of a wide variety of polymer modifiers will alter a neat binders strain behavior so that it is less resistant to strain accumulation than an unmodified version of the same binder. Within modifiers however we have seen in this study that binders which meet the same PG grade can have different levels of accumulated strain. In this study the Elvaloy 417 modifier outperformed both SBS crosslinked and non-crosslinked systems as well as an EVA system. It is worth noting that the SBS crosslinked product performed better than the non-crosslinked system. The real message one should take away from this analysis is that regardless of the additive type, it is the ability of that modifier to alter fundamental performance properties of the binder that really matters. Based on the mixture creep failure tests that we performed in mixtures produced from the different binders, the cumulative strain test appears to be one those fundamental performance tests. We were able to develop in our laboratory a mixture performance test using mix slices cut from gyratory specimens. These small slices are tested in static creep test in a suitable dynamic shear rheometer. We were able to show that mixes which exhibit long times to failure in this creep test are also those mixes which are produced from asphalt binders which have low values of accumulated strain as well as low phase angle values for the asphalt binder. Furthermore, in other research studies within our laboratory we have been able to correlate field rutting of mixtures to the creep results we have obtained using the same test employed in this study. In that study projects with low levels of rutting exhibited long flowtime to failure values. Therefore it is logical to suggest that mixes in this study which have longer flowtime to failure values should also be more resistant to permanent deformation. Lastly, using the data developed in this study two different analyses were performed to arrive at a binder phase angle value that could be related to mixes that are resistant to permanent deformation. It appears as though for these PG binders that mixes produced with binders with a phase angle of less than 7 degrees and preferably less than 68 degrees are going to be less prone to rapid creep strain failure and therefore less prone to permanent deformation. Page 22

24 APPENDIX The following pages contain SHRP PG grading reports on all of the Citgo Savannah blends that were produced, tested and reported in the foregoing pages. Also the SHRP PG grading reports for several blends made using Citgo s Paulsboro asphalt are included. The Paulsboro binder blends were made and tested, but the follow up mix work was not performed. Page 23

25 915 Commercial Court Onalaska, WI 5465 (68) Test Date: 3/19/21 Sample: CITGO 67-22, SAVANNAH, GA, BASE Flash Point, COC, Deg C Mass Loss, Wt. % Brookfield Viscosity, Pa.s TEST SHRP PERFORMANCE GRADE ANALYSIS C _kPa Min 23 Deg C Max 1. Max 3.215%.578 Solubility Wt. % Specific Gravity UNAGED PAV USING RESIDUE 2.2 kpa G*XSin(d) 5 kpa -S 3_MPa -m.3 Pressure Aging Vessel Temperature: 1 TEST SPECIFICATION RESULT TEST SPECIFICATION RESULT HANDLING AND SAFETY PROPERTIES MIX PERFORMANCE PROPERTIES <<SHRP TEMP Penetration Min 99% NA Direct Tension Strain 1_mm/min 1.% Stress 1mm/min MPa SAMPLE PG Passing Temp for PAV : ( )/2+4=24.65 Precise SHRP DELTA: =96.9 PAV-DS PAV- PAV- REGRESSION RESULTS PAV PARAMETER = 1 = 2.2 = 5 = 3 =.3 PHASE ANGLES When 1/J"=1: When 1/J"=2.2: When G"=5: TEMP AGING TEMP Precise SHRP Grade CRITICAL CRACKING TEMPERATURE For Pavement Constant=16 For Pavement Constant= G*/Sin(d) 1.85 G*/Sin(d) RATIO: Test #561 1/16/21

26 915 Commercial Court Onalaska, WI 5465 (68) Test Date: 2/5/21 Sample: Citgo 76-22, Savannah, GA, Superflex, A Flash Point, COC, Deg C Mass Loss, Wt. % Brookfield Viscosity, Pa.s TEST SHRP PERFORMANCE GRADE ANALYSIS C _kPa Min 23 Deg C Max 1. Max 3 UNAGED PAV USING RESIDUE 2.2 kpa G*XSin(d) 5 kpa Solubility Wt. % Specific Gravity -S 3_MPa -m.3 Pressure Aging Vessel Temperature: 1 TEST SPECIFICATION RESULT TEST SPECIFICATION RESULT HANDLING AND SAFETY PROPERTIES MIX PERFORMANCE PROPERTIES <<SHRP TEMP Penetration Min 99% NA Direct Tension Strain 1_mm/min 1.% Stress 1mm/min MPa SAMPLE PG Passing Temp for PAV : ( )/2+4=29.9 Precise SHRP DELTA: =17.2 PAV-DS PAV- PAV- REGRESSION RESULTS PAV PARAMETER = 1 = 2.2 = 5 = 3 =.3 PHASE ANGLES When 1/J"=1: When 1/J"=2.2: When G"=5: TEMP AGING TEMP Precise SHRP Grade CRITICAL CRACKING TEMPERATURE For Pavement Constant=16 For Pavement Constant= G*/Sin(d) G*/Sin(d) 3.96 RATIO: Test #546 1/16/21

27 915 Commercial Court Onalaska, WI 5465 (68) Test Date: 1/25/21 Sample: Flash Point, COC, Deg C Mass Loss, Wt. % Brookfield Viscosity, Pa.s TEST C SHRP PERFORMANCE GRADE ANALYSIS A-Citgo ( Savanah, GA ), 5% Elvax 15W 1._kPa Min 23 Deg C Max 1. Max 3.214% 1.66 Solubility Wt. % Specific Gravity UNAGED PAV USING RESIDUE 2.2 kpa G*XSin(d) 5 kpa -S 3_MPa -m.3 Pressure Aging Vessel Temperature: 1 TEST SPECIFICATION RESULT TEST SPECIFICATION RESULT HANDLING AND SAFETY PROPERTIES MIX PERFORMANCE PROPERTIES <<SHRP TEMP Min 99% NA Direct Tension Strain 1_mm/mi n Stress 1mm/min MPa SAMPLE Passing Temp for PAV : ( )/2+4=32 Precise SHRP DELTA: =16.8 PAV-DS PAV- PAV- REGRESSION RESULTS PAV PARAMETER = 1 = 2.2 = 5 = 3 =.3 PHASE ANGLES When 1/J"=1: When 1/J"=2.2: When G"=5: TEMP AGING TEMP Precise SHRP Grade CRITICAL CRACKING TEMPERATURE For Pavement Constant=16 For Pavement Constant=18 PG G*/Sin(d) 1.76 G*/Sin(d) RATIO: Temp G*/Sin(d)@ 76C Test #549 1/16/21

28 915 Commercial Court Onalaska, WI 5465 (68) Test Date: 1/25/21 Sample: Flash Point, COC, Deg C Mass Loss, Wt. % Brookfield Viscosity, Pa.s TEST C SHRP PERFORMANCE GRADE ANALYSIS A, Citgo 7-22 (Savannah, GA),.8% 417,.5% SPA TEST SPECIFICATION RESULT TEST SPECIFICATION RESULT 1._kPa Min 23 Deg C Max 1. Max 3.28% 1.92 Solubility Wt. % Specific Gravity UNAGED PAV USING RESIDUE 2.2 kpa MIX PERFORMANCE PROPERTIES HANDLING AND SAFETY PROPERTIES G*XSin(d) 5 kpa <<SHRP TEMP S 3_MPa Min 99% NA -m.3 Pressure Aging Vessel Temperature: 1 Direct Tension Strain 1_mm/mi n Stress 1mm/min MPa SAMPLE Passing Temp for PAV : ( )/2+4=31.7 Precise SHRP DELTA: =11.8 PAV-DS PAV- PAV- REGRESSION RESULTS PAV PARAMETER = 1 = 2.2 = 5 = 3 =.3 PHASE ANGLES When 1/J"=1: When 1/J"=2.2: When G"=5: TEMP AGING TEMP Precise SHRP Grade CRITICAL CRACKING TEMPERATURE For Pavement Constant=16 For Pavement Constant=18 PG G*/Sin(d) 1.92 G*/Sin(d) RATIO: Temp G*/Sin(d)@ 76C Test #544 1/16/21

29 915 Commercial Court Onalaska, WI 5465 (68) Test Date: 1/25/21 Sample: Flash Point, COC, Deg C Mass Loss, Wt. % Brookfield Viscosity, Pa.s TEST C SHRP PERFORMANCE GRADE ANALYSIS B, Citgo (Savanah, GA), 2% Kraton 1116, 1% Kraton 1118 (on Ross mixer),.1% Butaphalt TEST SPECIFICATION RESULT TEST SPECIFICATION RESULT 1._kPa Min 23 Deg C Max 1. Max 3.171% UNAGED PAV USING RESIDUE 2.2 kpa HANDLING AND SAFETY PROPERTIES MIX PERFORMANCE PROPERTIES G*XSin(d) 5 kpa <<SHRP TEMP Solubility Wt. % Specific Gravity -S 3_MPa Min 99% NA -m.3 Pressure Aging Vessel Temperature: 1 Direct Tension Strain 1_mm/mi n Stress 1mm/min MPa SAMPLE Passing Temp for PAV : ( )/2+4=29.55 Precise SHRP DELTA: =17.5 PAV-DS PAV- PAV- REGRESSION RESULTS PAV PARAMETER = 1 = 2.2 = 5 = 3 =.3 PHASE ANGLES When 1/J"=1: When 1/J"=2.2: When G"=5: TEMP AGING TEMP Precise SHRP Grade CRITICAL CRACKING TEMPERATURE For Pavement Constant=16 For Pavement Constant=18 PG G*/Sin(d) G*/Sin(d) 3.16 RATIO: Temp G*/Sin(d)@ 76C Test #545 1/16/21

30 APPENDIX 1 The following pages contain fatigue test results and frequency sweep test results on the Citgo Savannah mixes. The torsional fatigue test results show that the mixes modified with Elvaloy Citgoflex, and SBS all have essentially the same resistance to fatigue, which is better than the fatigue resistance of the control (base) binder. It is worth noting that the fatigue resistance of the Elvax blend is actually not as good as that of the control. This is particularly interesting when one considers that the G*xSin(delta) stiffness of the Elvax PAV residue was actually lower than any of the other binders at 22 C. This stiffness data is shown in the table below. TABLE A1 Binder formulation G*xSin(delta) of PAV residue at 22 C CCT TEMP OF PAV RESIDUE Citgo PG control 3497 kpa C PG made with Elvaloy 363 kpa C PG Citgoflex blend 3835 kpa C PG SBS blend 3679 kpa C PG Elvax blend 2715 kpa C It can be seen from Table A1 that although the Elvax reduced the PAV residue stiffness it did not improve the Critical Cracking Temperature relative to the control binder. In fact the addition of the Elvax caused the bituminous mix made from the Elvax modified binder to exhibit reduced fatigue resistance (SEETORSIONAL FATIGUE TAB) while not improving the low temperature properties. In contrast, all of the elastomeric binders did not appreciably alter the PAV residue stiffness. However, they all did improve the Critical Cracking temperature by 2 to 3.5 C and an examination of the torsional fatigue plot shows that all of the elastomeric binders also improved the fatigue resistance of the bituminous mixes made from those binders. All of the polymer additives did result in an increase of PG grade to that of a PG 76. However, as we saw earlier in this report the phase angle of the Elvax modified binder was not reduced to the same extent as the phase angles of the elastomer modified binders. Furthermore the discussion in Figures 17-2 makes the argument that the Elvax modified mix is borderline in terms of high temperature mix performance relative to the elastomer modified mixes. Also appended to this report are the results of frequency sweep tests conducted on the various mixes. From these results it is possible to observe that the G* (complex modulus) of all the mixes is nearly the same for all modifiers. The PG control mix has a modulus value similar to that of the other mixes. Since all of these mixes had been aged for 5 days at 85 C, it is safe to conclude that the stiffness of these mixes due to aging resulted in mixes with very similar properties. However the results based on creep testing, clearly showed that the lower the phase angle of the binder used in a mix, the longer it took that mix to fail. There is clearly a difference between mix stiffness as measured by G* and the resistance of that mix to creep failure. The binder phase angle and the mixture creep test seems to provide a basis for determining that resistance to failure. Page 24

31 FATIGUE RESULTS FOR MIXES PRODUCED WITH CITGO PG AND POLYMER MODIFIED BINDERS BLENDED FROM THE SAME BASE 1E+6 5E+5 1E+5 CYCLES TO FAILURE 5E+4 1E CONTROL, 64-22; R 2 =.83 CITGOFLEX; R 2 =.87 ELVALOY, 114A; R 2 =.83 SBS, 115B; R 2 =.84 ELVAX, 115A; R 2 = MICROSTRAIN 1/16/1 12:6:4 E:\(A)Rhios6_21\DUPONT 21\CITGO-21\DUPONT-CITGO MIX\FATIGUE RESULTS CITGO POLYMER MIX STUDY.spf

32 1 1 MasterCurve CITGO HZ.1% STRAIN G* MasterCurve CITGO HZ.1% STRAIN MasterCurve DH115B KRATON + BUTAPHALT IN CITGO BASE 1-115B, CITGO (GA) 76-22, 5d IDT, THICK, I, STEP TEMP, ARES (SeqTest 1) MasterCurve PG #1 114A ELVALOY USING CITGO BASE MasterCurve CITGOFLEX PG 76-22, 1 HZ,.1%STRAIN 1 9 G* ( ) [Pa] G* = 5.984x1 7 [Pa] Temp = [ C] 1 8 G* = 4.551x1 7 [Pa] Temp = [ C] Temp [ C] 9.

33 5x1 8 MasterCurve CITGO HZ.1% STRAIN G* MasterCurve CITGO HZ.1% STRAIN MasterCurve DH115B KRATON + BUTAPHALT IN CITGO BASE 1-115B, CITGO (GA) 76-22, 5d IDT, THICK, I, STEP TEMP, ARES (SeqTest 1) MasterCurve PG #1 114A ELVALOY USING CITGO BASE MasterCurve CITGOFLEX PG 76-22, 1 HZ,.1%STRAIN G* ( ) [Pa] 1 8 G* = 5.984x1 7 [Pa] Temp = [ C] G* = 4.551x1 7 [Pa] Temp = [ C] 2x Temp [ C] 75.

34 915 Commercial Court Onalaska, WI 5465 (68) Test Date: 2/7/2 Sample: Flash Point, COC, Deg C Mass Loss, Wt. % Brookfield Viscosity, Pa.s TEST SHRP PERFORMANCE GRADE ANALYSIS C Citgo 64-22, Paulsboro, NJ; Base for modification, FHWA study for DuPont TEST SPECIFICATION RESULT TEST SPECIFICATION RESULT 1._kPa Min 23 Deg C Max 1. Max 3.16%.46 Solubility Wt. % Specific Gravity UNAGED PAV USING RESIDUE 2.2 kpa MIX PERFORMANCE PROPERTIES HANDLING AND SAFETY PROPERTIES G*XSin(d) 5 kpa <<SHRP TEMP Penetration -S 3_MPa Min 99% NA -m Pressure Aging Vessel Temperature: 1 Direct Tension Strain 1_mm/min 1.% <<Temp at which PAV residue must be <5 to meet PG grade Stress 1mm/min MPa SAMPLE PG Passing Temp for PAV : ( )/2+4=23.4 Precise SHRP DELTA: =92.6 PAV-DS PAV- PAV- REGRESSION RESULTS PAV PARAMETER = 1 = 2.2 = 5 = 3 =.3 PHASE ANGLES When 1/J"=1: When 1/J"=2.2: When G"=5: TEMP AGING TEMP Precise SHRP Grade CRITICAL CRACKING TEMPERATURE For Pavement Constant=16 For Pavement Constant= G*/Sin(d) G*/Sin(d) RATIO: Test #144 1/16/21

35 915 Commercial Court Onalaska, WI 5465 (68) Test Date: 12/22/2 Sample: Flash Point, COC, Deg C Mass Loss, Wt. % Brookfield Viscosity, Pa.s TEST C SHRP PERFORMANCE GRADE ANALYSIS C, CITGO 76-22, PAULSBURO, NJ 1._kPa Min 23 Deg C Max 1. Max 3.137% Solubility Wt. % Specific Gravity UNAGED PAV USING RESIDUE 2.2 kpa G*XSin(d) 5 kpa -S 3_MPa -m.3 Pressure Aging Vessel Temperature: 1 TEST SPECIFICATION RESULT TEST SPECIFICATION RESULT HANDLING AND SAFETY PROPERTIES MIX PERFORMANCE PROPERTIES <<SHRP TEMP Min 99% NA Direct Tension Strain 1_mm/mi n Stress 1mm/min MPa SAMPLE Passing Temp for PAV : (8.3-24)/2+4=32.15 Precise SHRP DELTA: =14.3 PAV-DS PAV- PAV- REGRESSION RESULTS PAV PARAMETER = 1 = 2.2 = 5 = 3 =.3 PHASE ANGLES When 1/J"=1: When 1/J"=2.2: When G"=5: TEMP AGING TEMP Precise SHRP Grade CRITICAL CRACKING TEMPERATURE For Pavement Constant=16 For Pavement Constant=18 PG G*/Sin(d) G*/Sin(d) RATIO: Temp G*/Sin(d)@ 76C Test #511 1/16/21

36 915 Commercial Court Onalaska, WI 5465 (68) Test Date: 1/19/21 Sample: Flash Point, COC, Deg C Mass Loss, Wt. % Brookfield Viscosity, Pa.s TEST C SHRP PERFORMANCE GRADE ANALYSIS B, Citgo 7-22 (Paulsboro, NJ), 5% Elvax 15W 1._kPa Min 23 Deg C Max 1. Max 3.157% Solubility Wt. % Specific Gravity UNAGED PAV USING RESIDUE 2.2 kpa G*XSin(d) 5 kpa -S 3_MPa -m.3 Pressure Aging Vessel Temperature: 1 TEST SPECIFICATION RESULT TEST SPECIFICATION RESULT HANDLING AND SAFETY PROPERTIES MIX PERFORMANCE PROPERTIES <<SHRP TEMP Min 99% NA Direct Tension Strain 1_mm/mi n Stress 1mm/min MPa SAMPLE Passing Temp for PAV : ( )/2+4=34.55 Precise SHRP DELTA: =14.3 PAV-DS PAV- PAV- REGRESSION RESULTS PAV PARAMETER = 1 = 2.2 = 5 = 3 =.3 PHASE ANGLES When 1/J"=1: When 1/J"=2.2: When G"=5: TEMP AGING TEMP Precise SHRP Grade CRITICAL CRACKING TEMPERATURE For Pavement Constant=16 For Pavement Constant=18 PG G*/Sin(d) 1.91 G*/Sin(d) RATIO: Temp G*/Sin(d)@ 76C Test #542 1/16/21

37 915 Commercial Court Onalaska, WI 5465 (68) Test Date: 1/19/21 Sample: Flash Point, COC, Deg C Mass Loss, Wt. % Brookfield Viscosity, Pa.s TEST C SHRP PERFORMANCE GRADE ANALYSIS A, Citgo 7-22 (Paulsboro,NJ),.8% 417,.5% SPA TEST SPECIFICATION RESULT TEST SPECIFICATION RESULT 1._kPa Min 23 Deg C Max 1. Max 3.257% 1.62 Solubility Wt. % Specific Gravity UNAGED PAV USING RESIDUE 2.2 kpa MIX PERFORMANCE PROPERTIES HANDLING AND SAFETY PROPERTIES G*XSin(d) 5 kpa <<SHRP TEMP S 3_MPa Min 99% NA -m.3 Pressure Aging Vessel Temperature: 1 Direct Tension Strain 1_mm/mi n Stress 1mm/min MPa SAMPLE Passing Temp for PAV : ( )/2+4=32.85 Precise SHRP DELTA: =15.9 PAV-DS PAV- PAV- REGRESSION RESULTS PAV PARAMETER = 1 = 2.2 = 5 = 3 =.3 PHASE ANGLES When 1/J"=1: When 1/J"=2.2: When G"=5: TEMP AGING TEMP Precise SHRP Grade CRITICAL CRACKING TEMPERATURE For Pavement Constant=16 For Pavement Constant=18 PG G*/Sin(d) G*/Sin(d) RATIO: Temp G*/Sin(d)@ 76C Test #55 1/16/21

38 915 Commercial Court Onalaska, WI 5465 (68) Test Date: 1/19/21 Sample: Flash Point, COC, Deg C Mass Loss, Wt. % Brookfield Viscosity, Pa.s TEST C SHRP PERFORMANCE GRADE ANALYSIS C, Citgo 7-22 (Paulsboro, NJ), 2% Kraton 1116, 1% Kraton 1118 (w/ross mixer),.1% Butaphalt TEST SPECIFICATION RESULT TEST SPECIFICATION RESULT 1._kPa.171% UNAGED PAV USING RESIDUE Min 23 Deg C Max 1. Max kpa MIX PERFORMANCE PROPERTIES HANDLING AND SAFETY PROPERTIES G*XSin(d) 5 kpa <<SHRP TEMP Solubility Wt. % Specific Gravity -S 3_MPa Min 99% NA -m.3 Pressure Aging Vessel Temperature: 1 Direct Tension Strain 1_mm/mi n Stress 1mm/min MPa SAMPLE Passing Temp for PAV : ( )/2+4=31.5 Precise SHRP DELTA: =15.2 PAV-DS PAV- PAV- REGRESSION RESULTS PAV PARAMETER = 1 = 2.2 = 5 = 3 =.3 PHASE ANGLES When 1/J"=1: When 1/J"=2.2: When G"=5: TEMP AGING TEMP Precise SHRP Grade CRITICAL CRACKING TEMPERATURE For Pavement Constant=16 For Pavement Constant=18 PG G*/Sin(d) G*/Sin(d) RATIO: Temp G*/Sin(d)@ 76C Test #543 1/16/21