Surfactants And Interfacial Phenomena

https://arpi.unipi.it/bitstream/11568/798598/2/polacco%20798598.pdf

A review of the fundamentals of polymer-modified asphalts: Asphalt/polymer interactions and principles of compatibility

Morphology, rheology, and physical properties of polymer-modified asphalt binders

Molecular dynamics study of oxidative aging effect on asphalt binder properties

http://eprints.um.edu.my/8811/1/Investigation_of_the_possibility_of_using_waste_cooking_oil_as_a_rejuvenating_agent_for_aged_bitumen.pdf

Investigation of the possibility of using waste cooking oil as a rejuvenating agent for aged bitumen

This paper gives a mathematical-based procedure in order to construct master-curves from complex-modulus measurements. The method is based on the Kramers-Kronig relations linking modulus and phase angle of a complex function. Three pure bitumens, one polymer-modified-binder and two mixtures are chosen to validate the possible use of this methodology and apply it. Assumptions which are needed to apply this procedure, are verified on complex-modulus data measured from these materials. Hence, master-curves can be built without introducing error from manual adjustement. The method seems to be suitable for binders and mixtures as soon as their behaviour is in agreement with the time-temperature equivalency principle. In conclusion, some interpretations of the WLF constants are given.

/pdf/a-mathematical-based-master-curve-construction-method-1qusft1xha.pdf

A mathematical-based master-curve construction method applied to complex modulus of bituminous materials

Physico-chemical analysis of five hard bitumens: Identification of chemical species and molecular organization before and after artificial aging

In the past years a wide discussion has been held among asphalt researchers regarding the existence and interpretation of observed microstructures on bitumen surfaces. To investigate this, the RILEM technical committee on nano bituminous materials 231-NBM has conducted a round robin study combining differential scanning calorimetry (DSC) and Atomic Force Microscopy (AFM). From this, methods for performing DSC and AFM tests on bitumen samples and determination of the influence of wax on the observed phases, taking into account thermal history, sample preparation and annealing procedure, are presented and critically discussed. DSC is used to measure various properties and phenomena that indicate physical changes such as glass transition temperature (T g) and phase transition such as melting and crystallization. In the case of existence of wax, either natural or synthetic, it can further indicate the melting point of wax, that could be used to determine wax content. The results from seven laboratories show that T g temperatures obtained from the heating scans are more repeatable and easier to obtain in comparison to the cooling scans. No significant difference was noted for T g's obtained from the first and second heating scans. AFM is an imaging tool used to characterize the microstructures on a bituminous surface. Using AFM three phases in the materials with wax could be distinguished. The changes in the phases observed with AFM for increases in temperature were correlated with the DSC curve, and it could be established that the so called "Bee" structure disappeared around the melting peak in the DSC curve. Thus, this research has confirmed the relation between the microstructures on a bitumen surface and the wax content. cop. 2013 RILEM.

/pdf/laboratory-investigation-of-bitumen-based-on-round-robin-dsc-3azr5j97j4.pdf

Laboratory investigation of bitumen based on round robin DSC and AFM tests

This paper evaluates the applicability of different shifting techniques for constructing complex modulus master curves using the time-temperature superposition principle (TTSP). A database of complex modulus results of unmodified bitumens, polymer modified bitumens (PMBs), bitumen-filler mastics, unaged and aged bitumens was used together with a Generalized Logistic Sigmoidal Model to assess the validity of seven different shifting approaches. Except for the Laboratoire Central des Ponts et Chaussees (LCPC) method, the construction of master curves was done using the Generalised Logistic Sigmoidal Model and non-linear least squares regression optimization with the aid of the Microsoft Excel Spreadsheet Solver function. The goodness-of-fit for the various shifting techniques and functions was assessed through graphical and statistical methods. From the study, it was found that a numerical shift approach using non-linear least squares produced the best fit between experimental and predicted data in terms of both graphical and goodness-of-fit statistics. The ranking of the other shifting techniques consisted of the LCPC approach, followed by the William, Landel and Ferry (WLF), Modified Kaelble, Viscosity Temperature Susceptibility (VTS), Arrhenius and Log-Linear methods. However, most of the equations are basically empirical and they are not expected to be strictly obeyed by any materials. Discrepancies were still evident, even for the better functions, for those materials that demonstrated a deviation from the thermorheological simplicity of the rheological behaviour as found for highly structured bitumens following high degrees of polymer modification and/or oxidative ageing.

A comparative study of the influence of shift factor equations on master curve construction

A non-linear viscoelastic viscoplastic model is proposed for the tensilebehaviour of aramid fibres, based on an analysis of the deformationmechanisms of these materials. This model uses the macroscopicformulation developed by Schapery together with the plasticity conceptof Perzyna. A simple identification procedure for the model parametershas been developed using creep/recovery cycles at different load levels.The identification reveals that two of the four parameters of theviscoelastic model (g 1 and a σ) are independent of stresslevel. This may be due to the simple and regular nature of the fibrestructure. The model enables the parameters which characterise thenon-linear reversible viscoelasticity to be identified independentlyfrom those which characterise the viscoplasticity. The model predictionsare compared to experimental data for a more complex load sequence andreasonable correlation is obtained.

Emmanuel Chailleux

Papers

A mathematical-based master-curve construction method applied to complex modulus of bituminous materials

Physico-chemical analysis of five hard bitumens: Identification of chemical species and molecular organization before and after artificial aging

Laboratory investigation of bitumen based on round robin DSC and AFM tests

A comparative study of the influence of shift factor equations on master curve construction

Modelling the Non-Linear Viscoelastic and Viscoplastic Behaviour of Aramid Fibre Yarns