Gordon Airey - Academia.edu (original) (raw)
Papers by Gordon Airey
... The rheological changes that occurred after aging for three base bitumens and fifteen PMB... more ... The rheological changes that occurred after aging for three base bitumens and fifteen PMB'susing conventional binder specification tests ... Authors: Airey, GD. BROWN, SF. Publication Date: 1998. Serial: Journal of the Association of Asphalt Paving Technologists ...
Construction and Building Materials, Aug 1, 2018
CRC Press eBooks, Jul 20, 2017
Springer eBooks, Sep 26, 2021
Transportation research procedia, 2016
Springer eBooks, Aug 30, 2015
Transportation Research Record, May 5, 2022
The paper describes the use of a purpose built hydraulic tension-compression apparatus to investi... more The paper describes the use of a purpose built hydraulic tension-compression apparatus to investigate the linearity limits and linear viscoelastic (LVE) rheological characteristics of a range of unmodified and modified (polymer and process) asphalt mixtures. The asphalt mixtures consist of dense bitumen macadam (DBM), hot rolled asphalt (HRA) and HRA mortar mixtures with conventional 50 pen bitumen, radial and linear SBS PMBs, EVA PMB and multigrade bitumen. Cylindrical specimens of the mixtures were subjected to sinusoidal loading conditions at temperatures between 10 and 40 degrees C, firstly, under stress sweep conditions and, secondly, under frequency sweep conditions. The results indicate that the linearity limits of behaviour for the asphalt mixtures were strain dependant and found to be between 20 and 100 microstrain for the DBM and HRA mixtures and between 50 and 150 microstrain for the HRA mortars. In general, the LVE rheological characteristics of the asphalt mixtures were similar with differences in complex modulus and phase angle only being found at intermediate temperatures and frequencies and attributed to the unique rheological characteristics of the binders. For the covering abstract see ITRD E117840.
Engineering Failure Analysis, Sep 1, 2017
Road Materials and Pavement Design, Mar 29, 2017
Construction and Building Materials, Sep 1, 2015
Materials and Structures, Jul 11, 2015
There are exchangeable uses between zero shear rate viscosity and zero frequency complex viscosit... more There are exchangeable uses between zero shear rate viscosity and zero frequency complex viscosity. However, these values are no mean similar as zero shear rate viscosity presents the resistance to flow of bitumen and zero frequency complex viscosity for the viscoelastic properties. To compare these values, three types of straight-run bitumen, 70/100, 100/150, 160/220 Pen, one artificially aged binder, and four bitumen-filler mastics are tested under viscometry and dynamic oscillation condition at 20, 40, and 60degreesC. The bitumen-filler mastics are made from bitumen 40/60 Pen, cement or gritstone filler with 35 and 65% by mass. Zero shear viscosity values (ZSV) are extrapolated from viscometry and dynamic oscillation data by using Cross model with the help of Matlab software. The comparison between these values shows that at high temperatures, 60degreesC for instance, extrapolated ZSV values from viscometry and dynamic oscillation are almost the same. However, at medium and low temperatures, these values are quite different. Especially with stiff bitumen and bitumen-filler mastics, ZSV from viscometry data is considerably higher than that from dynamic oscillation data. This is due to the difference in test configuration. In oscillation test, the strain is controlled to ensure material working in viscoelastic regime. On the contrary, unlimited strain in viscometer test might cause the higher rate of fluidity loss as the material performs under viscoplastic manner. This results in higher extrapolated ZSV. For the covering abstract see ITRD E144473.
With the advent of higher axle loads and increasing traffic volumes, there has been an increase i... more With the advent of higher axle loads and increasing traffic volumes, there has been an increase in the use of polymer modified bitumens (PMBs) and other specialised binders and, therefore, an increase in modified asphalt pavements. Such modification significantly alters the rheological properties of the binder, which are not necessaily characterised by conventional, empirical binder properties. This has led to an increasing interest in the use of fundamental rheological parameters to specify bituminous binders. One such test is the dynamic shear rheometer (DSR), considered to be the most complex and powerful instrument for characterising the flow properties of bitumen. This paper presents a statistical evaluation of the sensitivity of different sample preparation methods on DSR rheological properties. The sample preparation methods that have been evaluated include those recommended in the UK Specification for Highway Works and those described in the AASHTO standard test method for determining the rheological properties of bitumen using a DSR as recommended by the Strategic Highway Research Programme (SHRP) Researchers. For the covering abstract see ITRD E107185.
The laboratory measurement of bond strength between asphalt layers undertaken using a modified ve... more The laboratory measurement of bond strength between asphalt layers undertaken using a modified version of the Leutner shear test and a laboratory version of the torque test is described. Cores were taken from slabs prepared in the laboratory as well as from the field coring. The shear strength measured from the Leutner test was found to increase approximately in proportion to the shear displacement at the shear strength, independent of the bond condition. The shear strengths from the 20mm dense bitumen macadam / 28mm dense bitumen macadam specimens were generally found to be lower than the corresponding shear strengths of the stone mastic asphalt / 20 mm dense bitumen macadam specimens. The shear strength was found to decrease as the temperature increases and as the loading rate decreases. The peak torque values measured from the torque test for the stone mastic asphalt / 20 mm dense bitumen macadam specimens was found to be generally higher than those for the 20mm dense bitumen macadam / 28mm dense bitumen macadam specimens. The peak torque was found to reduce with increasing temperature and there was found to be a reasonably good correlation between the shear strength measured from the Leutner test and the peak torque. Results from Leutner tests on field cores showed that the shear strength at the interface between surfacing and binder course is typically higher than at the interface between binder course and base. The maximum shear strength measured using the modified Leutner shear test and the peak torque showed a similar correlation to that obtained from the laboratory manufactured specimens. For the covering abstract see ITRD E145817
CRC Press eBooks, Sep 5, 2018
... The rheological changes that occurred after aging for three base bitumens and fifteen PMB... more ... The rheological changes that occurred after aging for three base bitumens and fifteen PMB'susing conventional binder specification tests ... Authors: Airey, GD. BROWN, SF. Publication Date: 1998. Serial: Journal of the Association of Asphalt Paving Technologists ...
Construction and Building Materials, Aug 1, 2018
CRC Press eBooks, Jul 20, 2017
Springer eBooks, Sep 26, 2021
Transportation research procedia, 2016
Springer eBooks, Aug 30, 2015
Transportation Research Record, May 5, 2022
The paper describes the use of a purpose built hydraulic tension-compression apparatus to investi... more The paper describes the use of a purpose built hydraulic tension-compression apparatus to investigate the linearity limits and linear viscoelastic (LVE) rheological characteristics of a range of unmodified and modified (polymer and process) asphalt mixtures. The asphalt mixtures consist of dense bitumen macadam (DBM), hot rolled asphalt (HRA) and HRA mortar mixtures with conventional 50 pen bitumen, radial and linear SBS PMBs, EVA PMB and multigrade bitumen. Cylindrical specimens of the mixtures were subjected to sinusoidal loading conditions at temperatures between 10 and 40 degrees C, firstly, under stress sweep conditions and, secondly, under frequency sweep conditions. The results indicate that the linearity limits of behaviour for the asphalt mixtures were strain dependant and found to be between 20 and 100 microstrain for the DBM and HRA mixtures and between 50 and 150 microstrain for the HRA mortars. In general, the LVE rheological characteristics of the asphalt mixtures were similar with differences in complex modulus and phase angle only being found at intermediate temperatures and frequencies and attributed to the unique rheological characteristics of the binders. For the covering abstract see ITRD E117840.
Engineering Failure Analysis, Sep 1, 2017
Road Materials and Pavement Design, Mar 29, 2017
Construction and Building Materials, Sep 1, 2015
Materials and Structures, Jul 11, 2015
There are exchangeable uses between zero shear rate viscosity and zero frequency complex viscosit... more There are exchangeable uses between zero shear rate viscosity and zero frequency complex viscosity. However, these values are no mean similar as zero shear rate viscosity presents the resistance to flow of bitumen and zero frequency complex viscosity for the viscoelastic properties. To compare these values, three types of straight-run bitumen, 70/100, 100/150, 160/220 Pen, one artificially aged binder, and four bitumen-filler mastics are tested under viscometry and dynamic oscillation condition at 20, 40, and 60degreesC. The bitumen-filler mastics are made from bitumen 40/60 Pen, cement or gritstone filler with 35 and 65% by mass. Zero shear viscosity values (ZSV) are extrapolated from viscometry and dynamic oscillation data by using Cross model with the help of Matlab software. The comparison between these values shows that at high temperatures, 60degreesC for instance, extrapolated ZSV values from viscometry and dynamic oscillation are almost the same. However, at medium and low temperatures, these values are quite different. Especially with stiff bitumen and bitumen-filler mastics, ZSV from viscometry data is considerably higher than that from dynamic oscillation data. This is due to the difference in test configuration. In oscillation test, the strain is controlled to ensure material working in viscoelastic regime. On the contrary, unlimited strain in viscometer test might cause the higher rate of fluidity loss as the material performs under viscoplastic manner. This results in higher extrapolated ZSV. For the covering abstract see ITRD E144473.
With the advent of higher axle loads and increasing traffic volumes, there has been an increase i... more With the advent of higher axle loads and increasing traffic volumes, there has been an increase in the use of polymer modified bitumens (PMBs) and other specialised binders and, therefore, an increase in modified asphalt pavements. Such modification significantly alters the rheological properties of the binder, which are not necessaily characterised by conventional, empirical binder properties. This has led to an increasing interest in the use of fundamental rheological parameters to specify bituminous binders. One such test is the dynamic shear rheometer (DSR), considered to be the most complex and powerful instrument for characterising the flow properties of bitumen. This paper presents a statistical evaluation of the sensitivity of different sample preparation methods on DSR rheological properties. The sample preparation methods that have been evaluated include those recommended in the UK Specification for Highway Works and those described in the AASHTO standard test method for determining the rheological properties of bitumen using a DSR as recommended by the Strategic Highway Research Programme (SHRP) Researchers. For the covering abstract see ITRD E107185.
The laboratory measurement of bond strength between asphalt layers undertaken using a modified ve... more The laboratory measurement of bond strength between asphalt layers undertaken using a modified version of the Leutner shear test and a laboratory version of the torque test is described. Cores were taken from slabs prepared in the laboratory as well as from the field coring. The shear strength measured from the Leutner test was found to increase approximately in proportion to the shear displacement at the shear strength, independent of the bond condition. The shear strengths from the 20mm dense bitumen macadam / 28mm dense bitumen macadam specimens were generally found to be lower than the corresponding shear strengths of the stone mastic asphalt / 20 mm dense bitumen macadam specimens. The shear strength was found to decrease as the temperature increases and as the loading rate decreases. The peak torque values measured from the torque test for the stone mastic asphalt / 20 mm dense bitumen macadam specimens was found to be generally higher than those for the 20mm dense bitumen macadam / 28mm dense bitumen macadam specimens. The peak torque was found to reduce with increasing temperature and there was found to be a reasonably good correlation between the shear strength measured from the Leutner test and the peak torque. Results from Leutner tests on field cores showed that the shear strength at the interface between surfacing and binder course is typically higher than at the interface between binder course and base. The maximum shear strength measured using the modified Leutner shear test and the peak torque showed a similar correlation to that obtained from the laboratory manufactured specimens. For the covering abstract see ITRD E145817
CRC Press eBooks, Sep 5, 2018