Chemo-mechanics of ageing on bituminous materials

Ageing of bitumen is a complex process. It is accompanied by major chemical and mechanical changes. In this study, Fourier Transform Infrared (FTIR) spectrometer and Dynamic Shear Rheometer (DSR) tests were utilized to investigate the effect of ageing on the chemical and mechanical properties of bituminous materials. Bitumen films with thickness of 2 mm were exposed to laboratory ageing at various conditions. Specifically, different combinations of ageing time, temperature and pressure were applied on the materials. The FTIR tests results were used to quantify the changes in the chemical functional groups and to calculate ageing indices (carbonyl index and sulfoxide index) of bitumen. In addition, the DSR tests results were analysed to determine the evolution of the rheological properties of bitumen. A linear relationship was made between the ageing indices and complex shear modulus, providing thus a chemo-mechanics framework to describe bitumen ageing. The results were validated by using data of field aged samples. Finally, the influence of ageing on the parameters of two viscoelastic models was determined

Chemo-mechanics of ageing on bituminous materials

Ageing of bitumen is a complex process. It is accompanied by major chemical and mechanical changes. In this study, Fourier Transform Infrared (FTIR) spectrometer and Dynamic Shear Rheometer (DSR) tests were utilized to investigate the effect of ageing on the chemical and mechanical properties of bituminous materials. Bitumen films with thickness of 2 mm were exposed to laboratory ageing at various conditions. Specifically, different combinations of ageing time, temperature and pressure were applied on the materials. The FTIR tests results were used to quantify the changes in the chemical functional groups and to calculate ageing indices (carbonyl index and sulfoxide index) of bitumen. In addition, the DSR tests results were analysed to determine the evolution of the rheological properties of bitumen. A linear relationship was made between the ageing indices and complex shear modulus, providing thus a chemo-mechanics framework to describe bitumen ageing. The results were validated by using data of field aged samples. Finally, the influence of ageing on the parameters of two viscoelastic models was determined.Pavement Engineerin

Smart sensors in asphalt: monitoring key process parameters during and post construction

The Fibre Bragg Gratings (FBG) technology based on integrated photonics, offers specific benefits including thermal mapping, damage detection, shape- and distributed sensing. This makes it useful for determining pavement behaviour during extreme weather conditions e.g. freeze-thaw cycles when harsh winter conditions could damage the asphalt surfacing layer. However, the harsh construction environment and traffic loading highlights the high-risk challenge of installing the sensor into the asphalt layer in a noninvasive manner so that the key parameters are accurately measured during and after construction.Pavement Engineerin