__________________________________________________________________________Table of contents I
Table of contents
Chapter 1
Rheology
1
1.1 Linear viscoelasticity 1 1.1.1 Elasticity 1 1.1.2 Viscosity 2 1.1.3 Linear viscoelasticity 31.2 Time dependent experiments in shear 4
1.2.1 Two basic mechanical models 5
1.2.1.1 Maxwell Body 5
1.2.1.2 Voigt Body 5
1.2.2 Stress relaxation 6
1.2.3 Creep and recovery 8
1.2.4 Dynamic creep 13
1.2.5 Small amplitude oscillatory sweep 15
1.2.6 Viscometry 16
1.3 Mechanical models for viscoelasticity 19
1.3.1 The Burger model 19
1.3.2 The generalized Maxwell model 20
1.3.3 The generalized Voigt model 21
1.4 Time temperature superposition principle 23
1.5 Non-linear viscoelasticity 26
1.5.1 Cauchy and Finger tensors 27
1.5.2 Rubberlike liquid model 27
1.5.3 Wagner’s equation: the damping function 28
1.5.4 Separable non-linear viscoelasticity 30
1.5.5 Non-separable non-linear viscoelasticity 31
Chapter 2
Asphalt: an overview
33
2.1 Definition 33
2.2 Chemical composition 34
2.3 Structure 35
2.4 Polymer modified asphalts (PMAs) 37
2.4.1 Modifiers 38
2.4.2 SEBS-modified asphalts 39
2.5 Road paving: the problem of rutting 40
Chapter 3
Materials and methods
42
3.1 Materials 42
3.2 Preparation of PMAs 42
3.3 Physical characterization 43
__________________________________________________________________________Table of contents
II
3.3.2 Penetration test 43
3.3.3 Fluorescence microscopy 43
3.4 Rheological characterization 44
3.4.1 Samples: loading and conditioning procedure 44
3.4.2 Simple creep 45
3.4.3 Dynamic creep 45
3.4.4 Stress relaxation 45
3.4.5 Viscometry 46
3.4.6 Fitting of experimental data 46
Chapter 4
Results and discussion
50
4.1 Characterization of PMAs 50
4.1.1 Softening point test 50
4.1.2 Penetration test 51
4.1.3 Fluorescence microscopy 51
4.2 Rheological characterization 55
4.2.1 Simple creep 55
4.2.1.1 Results and discussion 55
4.2.1.2 Short cycles 65
4.2.1.3 Fitting with linear viscoelastic models 70
4.2.2 Dynamic creep 81
4.2.2.1 Results and discussion 81
4.2.2.2 Fitting with linear viscoelastic models 93 4.2.3 Note on the fitting parameters (viscosity) 103
4.3 Stress relaxation 105
