Bitumen ageing Studying the ageing behaviour relations of an adjusted artificial ageing protocol

130 Pages·2016·13.38 MB·English

Department of Materials Science and Engineering
Bitumen ageing
Studying the ageing behaviour relations of an adjusted
artificial ageing protocol
W.H. de Goeij
Supervisor : Dr. ir. D.Q. van Lent
Professor : Prof. dr. ir. H.E.J.G. Schlangen
Specialisation : Materials Engineering and Applications
Type of report : MSc. Thesis
Date : August 29, 2016

Bitumen ageing -
Studying the ageing behaviour relations of an
adjusted artificial ageing protocol
by
W.H. de Goeij
to obtain the degree of Master of Science
at the Delft University of Technology,
to be defended publicly on Wednesday September 07, 2016 at 16:00
Student number: 1199714
Project duration: August 24, 2015 – September 07, 2016
Thesis committee: Prof. dr. ir. H.E.J.G. Schlangen, TU Delft, chairman
Prof. dr. ir. J. Sietsma, TU Delft,
Dr. ir. D.Q. van Lent, TNO, supervisor
Ir. G.C. Leegwater TU Delft

Contents
I Literature Review 5
1 Literature review 7
1.1 Introduction to bitumen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.1.1 Chemical composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.1.2 Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2 Bitumen rheology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.2.1 Bitumen viscoelasticity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.2.2 Simulation and modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.3 Bitumen ageing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.3.1 Historical context. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.3.2 Ageing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.3.3 Simulation of ageing - Ageing methods . . . . . . . . . . . . . . . . . . . . 24
1.3.4 The effects of ageing - Physical tests . . . . . . . . . . . . . . . . . . . . . 27
1.3.5 The effects of ageing - Chemical test . . . . . . . . . . . . . . . . . . . . . 29
1.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
II Experimental research 31
2 Materials and methods 33
2.1 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.1.1 Artificial ageing tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.2 Material characterizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.2.1 Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.2.2 Chemical composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
2.2.3 Chemical characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3 Ageing with time and temperature 49
3.1 Experimental set-up test 1A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.2 Experimental set-up test 1B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.3 Test results of experiments 1A and 1B . . . . . . . . . . . . . . . . . . . . . . . . 51
3.3.1 Rheological characterization - DSR . . . . . . . . . . . . . . . . . . . . . . 51
3.3.2 Characterization - FTIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
3.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
4 Ageing with time and pressure 61
4.1 Experimental set-up test 2A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.2 Experimental set-up test 2B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
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4.3 Test results of the rheological characterizations . . . . . . . . . . . . . . . . . . . 63
4.3.1 Observations regarding the DSR-results . . . . . . . . . . . . . . . . . . . 63
4.3.2 Discussion of the DSR-results . . . . . . . . . . . . . . . . . . . . . . . . . 69
4.4 Test results of the chemical characterizations . . . . . . . . . . . . . . . . . . . . 72
4.4.1 Observation and discussion regarding the FTIR-results . . . . . . . . . . . 72
5 Ageing with thickness and pressure 77
5.1 Experimental set-up test 3A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
5.2 Experimental set-up test 3B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
5.3 Test results of the rheological characterizations . . . . . . . . . . . . . . . . . . . 79
5.3.1 Observations regarding the DSR-results . . . . . . . . . . . . . . . . . . . 79
5.3.2 Discussion of the DSR-results . . . . . . . . . . . . . . . . . . . . . . . . . 84
5.4 Test results of the chemical characterizations . . . . . . . . . . . . . . . . . . . . 86
5.4.1 Observation and discussion regarding the FTIR-results . . . . . . . . . . . 86
5.5 Experimental set-up test 3C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
5.5.1 Test results of the rheological characterization . . . . . . . . . . . . . . . 92
5.5.2 Test results of the chemical characterization . . . . . . . . . . . . . . . . . 93
5.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
6 Interrelations between the various tests 97
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
6.1.1 Comparing test 2A & test 2B - Analysis and discussion . . . . . . . . . . 97
6.1.2 Comparing test 2A & test 3A - Analysis and discussion . . . . . . . . . . 99
6.1.3 Comparing test 3A & test 3B - Analysis and discussion . . . . . . . . . . 100
6.1.4 Comparing test 2B & test 3B - Analysis and discussion . . . . . . . . . . 102
6.1.5 Overpressure - Analysis and discussion . . . . . . . . . . . . . . . . . . . . 103
6.2 Blackspace diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
6.3 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
6.3.1 Regarding physical hardening . . . . . . . . . . . . . . . . . . . . . . . . . 111
6.3.2 Regarding equivalent ageing . . . . . . . . . . . . . . . . . . . . . . . . . . 112
6.3.3 Reflection on the practical consequences of this research . . . . . . . . . . 112
6.4 Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
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List of Figures
1.1 Functional groups in bitumen [1] . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2 Schematic illustration of the shift of molecular components towards more polar
fractions upon oxidation [2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.3 Damper system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.4 Spring system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.5 Phenomena: Creep upon constant stress and relaxation under constant strain. . . 12
1.6 Viscoelastic response of bitumen under a static load [3]. . . . . . . . . . . . . . . 13
1.7 Mass-damper systems: The upper system represents the Kelvin-Voigt model and
the lower system the Maxwell model. . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.8 1-D representation of the bitumen-aggregate-atmosphere system [4]. . . . . . . . 18
1.9 Distribution of the dissolved oxygen as a function of γ [4]. . . . . . . . . . . . . . 20
1.10 Aging of bitumen through different stages of its service life [3] . . . . . . . . . . . 22
1.11 Changeofthecomponentialcompositionduringmixing, layingandservicelifetime
[3] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1.12 Overview of ageing methods and their specific conditions [5] . . . . . . . . . . . . 25
1.13 Rotating Thin Film Oven (RTFO) [6] . . . . . . . . . . . . . . . . . . . . . . . . 25
1.14 Pressure Aging Vessel (PAV) [7] . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.15 Dynamic Shear Rheometer (DSR) at TNO laboratory . . . . . . . . . . . . . . . 29
1.16 The instrumental process of sample analysis displayed in five consecutive steps [8] 30
2.1 The set-up and backbone (red thread) of this research . . . . . . . . . . . . . . . 33
2.2 Left: The ’customized’ PAV; Right: Metal-tray entrance and accompanying
restriction of the cylinder’s internal diameter . . . . . . . . . . . . . . . . . . . . 35
2.3 The temperature controller displays the pre-set (lower) and measured (upper)
temperature for each thermocouple position. TC-1 indicates the atmosphere
temperature within the vessel and TC2-5 indicate the temperature of the steel
vessel measured at 4 different locations (i.e. cylinder core, upper and lower flanges) 36
2.4 Six square parallel plates (85x85mm) serving as Petri-dish-levels made from
stainless steel, connected through a coppered steel wire and positioned to the 7
cm with TIG-welds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.5 A needle-tip thermocouple (green) positioned in the middle of the cylinder to
give the temperature of the gas medium inside the vessel. Right: A manometer,
gas release tap (black) and safety pressure relief valve set at 45 bar (yellow) to
monitor and control pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
2.6 Schematic illustration of the DSR operation mode [3] . . . . . . . . . . . . . . . . 39
2.7 Left: Sinusoidal load [3]. Right: Relation between geometry and load [9] . . . . . 40
2.8 Relation between |G∗| and δ [3] . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.9 A graphical representation of the Iatroscan SARA-fraction of the Q8 70/100
bitumen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
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Page vi List of Figures
2.10 Background scan after multiple cleaning operations . . . . . . . . . . . . . . . . . 46
2.11 The effect of solvents and propellants (cleaning operations) on the middle-range
spectral characterization of the material . . . . . . . . . . . . . . . . . . . . . . . 46
2.12 The referential ’fingerprint’ or characterization of the 70/100 bitumen . . . . . . 47
2.13 Carbonyl spectral range: the area under the ’baseline’ indicates no sign of ageing 48
2.14 Sulfoxide spectral range: the area above the ’baseline’ indicates increasing absorp-
tion, i.e. ageing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.1 Build-in sample and its outer perimeter . . . . . . . . . . . . . . . . . . . . . . . 49
3.2 The complex modulus of test 1A at -20◦C and p measured after 6 different
atm
time intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
3.3 The phase angle of test 1A at -20◦C and p measured after 6 different time
atm
intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.4 Strain sweep at 20◦C and p indicating the LVR . . . . . . . . . . . . . . . . . 53
atm
3.5 The norm and phase angle of the complex modulus of test 1A at 20◦C . . . . . . 54
3.6 Hardening rate rate at 20◦C at ω=1 rad/s . . . . . . . . . . . . . . . . . . . . . . 55
3.7 Hardening rate at 20◦C at ω=10 rad/s . . . . . . . . . . . . . . . . . . . . . . . . 55
3.8 Hardening rate at 20◦C at ω=100 rad/s . . . . . . . . . . . . . . . . . . . . . . . 56
3.9 the norm and phase angle of the complex modulus of test 1A at 60◦C . . . . . . 57
3.10 A minimal amount of bitumen has leaked from around the upper perimeter after
approx. 120 hours of ageing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
3.11 The norm and phase angle of the complex modulus of test 1B, showing no
indication of ageing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
4.1 Ageing of bitumen in a separate furnace under pressurized conditions. . . . . . . 61
4.2 Vacuum pump, desiccator and a control pressure gauge . . . . . . . . . . . . . . 62
4.3 Complex modulus of test 2A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
4.4 Phase angle of test 2A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
4.5 The norm and phase angle of the complex modulus of the reference sample . . . 66
4.6 Both samples are aged for 168 hours at 21 bar and show bubble formation. The
left picture is taken after 23 minutes and the right after 2 hours after being
depressurized . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4.7 Left: The left picture displays the desiccation and porosity of the bitumen after
beingagesfor168hoursat21bar. Right: Therightpictureshowstheaccumulated
nitrogen and holes on the outside perimeter of the build-in sample . . . . . . . . 67
4.8 The norm and phase angle of the complex modulus of test 2B . . . . . . . . . . . 68
4.9 The periodic time-curvature of sample 0.1 bar aged for 480 hours and its mean
value that corresponds with sample 0.35 bar aged for 480 hours . . . . . . . . . . 69
4.10 Example of an mastercurve in which 2 demarcated frequency ranges, parallel and
deviating slopes are displayed [2] . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
4.11 FTIR-results of test 2A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.12 Reference shift in order to determine the carbonyl area . . . . . . . . . . . . . . . 74
4.13 FTIR-results of test 2B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
5.1 Pool formation after ageing in which the flattened bitumen after application was
covered with glass cups to restrict the amount of accumulated bitumen . . . . . . 78
5.2 Distribution of oxygen products over different thicknesses under equal ageing
conditions based on the dissolved oxygen distribution of van Oort (1953) . . . . . 78
5.3 Complex modulus of test 3A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
5.4 Phase angle of test 3A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
5.5 Complex modulus of test 3B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
5.6 Phase angle of test 3B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
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List of Figures Page vii
5.7 Marginal differences in thickness w.r.t. the target thickness . . . . . . . . . . . . 85
5.8 FTIR-results of test 3A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
5.9 The carbonyl range of test 3A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
5.10 The sulfoxide range of test 3A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
5.11 FTIR-results of test 3B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
5.12 Carbonyl range of test 3B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
5.13 Sulfoxide range of test 3B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
5.14 Variation of thickness at 21 bar and after 480 hours of ageing . . . . . . . . . . . 92
5.15 FTIR-results of test 3C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
5.16 Carbonyl range of test 3C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
5.17 Sulfoxide range of test 3C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
6.1 The complex modulus of all overpressurized samples . . . . . . . . . . . . . . . . 103
6.2 The phase angle of all overpressurized samples . . . . . . . . . . . . . . . . . . . 105
6.3 The empirical derived hypothesis about ageing behaviour of 70/100 bitumen. . . 106
6.4 The Blackspace diagram with this research’s ageing relations next to Hagos (2008)
and Liu (2011) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
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