Provided by the author(s) and University College Dublin Library in accordance with publisher poli... more Provided by the author(s) and University College Dublin Library in accordance with publisher policies. Please cite the published version when available.
The number of commercial vehicles using Irish roads has increased considerably in recent years, l... more The number of commercial vehicles using Irish roads has increased considerably in recent years, leading to higher demands being placed on pavement materials and increased use of polymer modified bitumens. This has also coincided with significant changes in Governmental policy which has produced large increases in Irish recycling rates. Improved recycling levels are set to provide Ireland with a new challenge: to find potential uses for the large quantities of recycled polymer that are becoming available. Towards this end, the potential of developing a recycled polymer modified binder was investigated. The polymers most commonly recycled in Ireland were identified and sourced from industry. Fundamental bitumen tests were conducted to assess the effect of the recycled polymer and a mixing methodology developed. It was found that the addition of 4% recycled HDPE into a pen grade binder produced the most promising results, and the mixing process was then optimised with respect to mixing parameters and binder additives. A developmental recycled binder was produced and compared in performance tests to binders currently used in road construction practice. Results obtained from wheel track and fatigue tests show that although the binder does not deliver equivalent performance levels to a proprietary polymer modified binder, it does out-perform traditional binders used in stone mastic asphalt. Recommendations are offered on the further development of the recycled polymer modified binder to achieve the standards currently required.
ABSTRACT Cold-mix bituminous materials offer a sustainable, cost effective alternative to traditi... more ABSTRACT Cold-mix bituminous materials offer a sustainable, cost effective alternative to traditional hot-mixes. Difficulties however can be encountered when specifying cold-mix materials due to the strong influence of time and temperature on material performance. In the field of concrete technology maturity methods are routinely used for assessing materials of known curing history. This research presents the development of a maturity approach for the assessment of cold-mix bituminous materials and its application for predicting the effect of climatic variations on in situ mixture performance. A strong correlation was observed between the calculated maturity and the measured stiffness for a range of conditioning temperatures and durations thus enabling the prediction of long and short-term material performance in situ where ambient conditions are known.
ABSTRACT: This paper presents the results of ongoing research on the mechanical performance of a ... more ABSTRACT: This paper presents the results of ongoing research on the mechanical performance of a 20mm binder course asphalt pavement mix incorporating recycled asphalt pavement (RAP). A series of binder course mixes were designed containing varying percentages of ...
... Amir Tabakovi??1, Amanda Gibney2, Michael Gilchrist3, Ciaran McNally4 ... into the bituminous... more ... Amir Tabakovi??1, Amanda Gibney2, Michael Gilchrist3, Ciaran McNally4 ... into the bituminous mixtures (Public Roads, 2005; Fitzsimons & Gibney, 2004; Khalaf, 2004; Woodward, 2004; Perez Jimenez et al, 2004; Hossain et al, 1993; Emery, 1993; Gerardu & Hendriks, 1985). ...
This paper presents the physical properties of recycled asphalt pavement ͑RAP͒ and its influence ... more This paper presents the physical properties of recycled asphalt pavement ͑RAP͒ and its influence on the mechanical performance of a binder course asphalt pavement mix. A series of binder course mixes were designed containing varying percentages of RAP. A mix made from only virgin material was selected as the control mix for the investigation. The effect of introducing RAP into the binder course mix was evaluated through a series of laboratory tests including the Marshall test, the indirect tensile stiffness modulus test, the indirect tensile fatigue test and the water sensitivity test. A circular wheel track ͑CWT͒ was developed in order to study the dynamic effects of a rolling wheel traveling over an asphalt pavement. The CWT was commissioned within a temperature controlled room along with a customized data acquisition system. The system involves the testing of rectangular slabs and allows for the investigation of dynamic tensile strain. The laboratory tests have shown that the introduction of RAP to the binder course mix resulted in an improvement in all mechanical properties. In particular, it was found that the mix containing up to 30% RAP, displayed improved fatigue resistance relative to the control mix manufactured from virgin materials.
This paper investigates the applicability of a cohesive zone model for simulating the performance... more This paper investigates the applicability of a cohesive zone model for simulating the performance of bituminous material subjected to quasi-static loading. The Dugdale traction law was implemented within a finite volume code in order to simulate the binder course mortar material response when subjected to indirect tensile loading. A uniaxial tensile test and a three-point bend test were employed to determine initial stress-strain curves at different test rates and the cohesive zone parameters (specifically, fracture energy and cohesive strength). Numerical results agree well with the experimental data up to the peak load and onset of fracture, demonstrating the value of the cohesive zone modelling technique in successfully predicting fracture initiation and maximum material strength.
ABSTRACT Cold-mix bituminous materials offer a sustainable, cost effective alternative to traditi... more ABSTRACT Cold-mix bituminous materials offer a sustainable, cost effective alternative to traditional hot-mixes. Difficulties however can be encountered when specifying cold-mix materials due to the strong influence of time and temperature on material performance. In the field of concrete technology maturity methods are routinely used for assessing materials of known curing history. This research presents the development of a maturity approach for the assessment of cold-mix bituminous materials and its application for predicting the effect of climatic variations on in situ mixture performance. A strong correlation was observed between the calculated maturity and the measured stiffness for a range of conditioning temperatures and durations thus enabling the prediction of long and short-term material performance in situ where ambient conditions are known.
Page 1. Abstract for COMPTEST conference, Porto, April 2006 DEVELOPMENT OF A COMBINED MICROMECHAN... more Page 1. Abstract for COMPTEST conference, Porto, April 2006 DEVELOPMENT OF A COMBINED MICROMECHANICS & DAMAGE MECHANICS MODEL FOR THE DESIGN OF ASPHALT PAVEMENTS A. Tabaković1,2, C. McNally1, LG Sorelli1, A. Gibney1, MD Gilchrist2* ...
ABSTRACT: This paper presents the results of ongoing research on the mechanical performance of a ... more ABSTRACT: This paper presents the results of ongoing research on the mechanical performance of a 20mm binder course asphalt pavement mix incorporating recycled asphalt pavement (RAP). A series of binder course mixes were designed containing varying percentages of ...
ABSTRACT There is a need for a method for assessing the results from changes in the potential dur... more ABSTRACT There is a need for a method for assessing the results from changes in the potential durability of road materials due to the inclusion of reclaimed and secondary component materials in the manufacture of new road materials. Such changes will have an effect on the cost of the construction maintenance, both financially to the client and environmentally to society in general, and any savings may be transitory. A site trial has been laid of mixtures with and without reclaimed asphalt and work started to assess their durability from early-life properties. The trials are being monitored for their initial performance whilst laboratory trials are concentrating on the combined effect of ageing and moisture damage on the performance of asphalt mixtures on the trial. All three strands are being used to develop life-cycle analysis models to customize them for the effect of using alternative component materials on the availability of the network and their overall financial and environmental cost, both initial and whole-life. The costs will be identified as being direct (of the construction and maintenance) and indirect (on society in general, such as congestion).
This paper investigates the applicability of a cohesive zone model for simulating the performance... more This paper investigates the applicability of a cohesive zone model for simulating the performance of bituminous material subjected to quasi-static loading. The Dugdale traction law was implemented within a finite volume code in order to simulate the binder course mortar material response when subjected to indirect tensile loading. A uniaxial tensile test and a three-point bend test were employed to determine initial stress-strain curves at different test rates and the cohesive zone parameters (specifically, fracture energy and cohesive strength). Numerical results agree well with the experimental data up to the peak load and onset of fracture, demonstrating the value of the cohesive zone modelling technique in successfully predicting fracture initiation and maximum material strength.
This paper presents the results of ongoing research on the mechanical performance of a 20mm binde... more This paper presents the results of ongoing research on the mechanical performance of a 20mm binder course asphalt pavement mix incorporating recycled asphalt pavement (RAP). A series of binder course mixes were designed containing varying percentages of RAP. A mix made only from virgin material was selected as the control mix for the investigation. The effect of introducing RAP into the binder course mix was evaluated through a series of laboratory tests including the Marshall Test, Indirect Tensile Stiffness Modulus Test, Indirect Tensile Fatigue Test and Water Sensitivity Test. A Circular Wheel Track (CWT) was developed in order to study the dynamic effects of a rolling wheel travelling over an asphalt pavement. The CWT was commissioned within a temperature controlled room along with a customised Data Acquisition (DAQ) system. The system involves the testing of rectangular slabs and allows for the investigation of the dynamic tensile strain. The dynamic tensile strain is digitally recorded and the loading effect assessed. The laboratory tests have shown that the introduction of RAP to the binder course mix resulted in an improvement in all mechanical properties. This was also observed in the dynamic tensile strain test.
Provided by the author(s) and University College Dublin Library in accordance with publisher poli... more Provided by the author(s) and University College Dublin Library in accordance with publisher policies. Please cite the published version when available.
The number of commercial vehicles using Irish roads has increased considerably in recent years, l... more The number of commercial vehicles using Irish roads has increased considerably in recent years, leading to higher demands being placed on pavement materials and increased use of polymer modified bitumens. This has also coincided with significant changes in Governmental policy which has produced large increases in Irish recycling rates. Improved recycling levels are set to provide Ireland with a new challenge: to find potential uses for the large quantities of recycled polymer that are becoming available. Towards this end, the potential of developing a recycled polymer modified binder was investigated. The polymers most commonly recycled in Ireland were identified and sourced from industry. Fundamental bitumen tests were conducted to assess the effect of the recycled polymer and a mixing methodology developed. It was found that the addition of 4% recycled HDPE into a pen grade binder produced the most promising results, and the mixing process was then optimised with respect to mixing parameters and binder additives. A developmental recycled binder was produced and compared in performance tests to binders currently used in road construction practice. Results obtained from wheel track and fatigue tests show that although the binder does not deliver equivalent performance levels to a proprietary polymer modified binder, it does out-perform traditional binders used in stone mastic asphalt. Recommendations are offered on the further development of the recycled polymer modified binder to achieve the standards currently required.
ABSTRACT Cold-mix bituminous materials offer a sustainable, cost effective alternative to traditi... more ABSTRACT Cold-mix bituminous materials offer a sustainable, cost effective alternative to traditional hot-mixes. Difficulties however can be encountered when specifying cold-mix materials due to the strong influence of time and temperature on material performance. In the field of concrete technology maturity methods are routinely used for assessing materials of known curing history. This research presents the development of a maturity approach for the assessment of cold-mix bituminous materials and its application for predicting the effect of climatic variations on in situ mixture performance. A strong correlation was observed between the calculated maturity and the measured stiffness for a range of conditioning temperatures and durations thus enabling the prediction of long and short-term material performance in situ where ambient conditions are known.
ABSTRACT: This paper presents the results of ongoing research on the mechanical performance of a ... more ABSTRACT: This paper presents the results of ongoing research on the mechanical performance of a 20mm binder course asphalt pavement mix incorporating recycled asphalt pavement (RAP). A series of binder course mixes were designed containing varying percentages of ...
... Amir Tabakovi??1, Amanda Gibney2, Michael Gilchrist3, Ciaran McNally4 ... into the bituminous... more ... Amir Tabakovi??1, Amanda Gibney2, Michael Gilchrist3, Ciaran McNally4 ... into the bituminous mixtures (Public Roads, 2005; Fitzsimons & Gibney, 2004; Khalaf, 2004; Woodward, 2004; Perez Jimenez et al, 2004; Hossain et al, 1993; Emery, 1993; Gerardu & Hendriks, 1985). ...
This paper presents the physical properties of recycled asphalt pavement ͑RAP͒ and its influence ... more This paper presents the physical properties of recycled asphalt pavement ͑RAP͒ and its influence on the mechanical performance of a binder course asphalt pavement mix. A series of binder course mixes were designed containing varying percentages of RAP. A mix made from only virgin material was selected as the control mix for the investigation. The effect of introducing RAP into the binder course mix was evaluated through a series of laboratory tests including the Marshall test, the indirect tensile stiffness modulus test, the indirect tensile fatigue test and the water sensitivity test. A circular wheel track ͑CWT͒ was developed in order to study the dynamic effects of a rolling wheel traveling over an asphalt pavement. The CWT was commissioned within a temperature controlled room along with a customized data acquisition system. The system involves the testing of rectangular slabs and allows for the investigation of dynamic tensile strain. The laboratory tests have shown that the introduction of RAP to the binder course mix resulted in an improvement in all mechanical properties. In particular, it was found that the mix containing up to 30% RAP, displayed improved fatigue resistance relative to the control mix manufactured from virgin materials.
This paper investigates the applicability of a cohesive zone model for simulating the performance... more This paper investigates the applicability of a cohesive zone model for simulating the performance of bituminous material subjected to quasi-static loading. The Dugdale traction law was implemented within a finite volume code in order to simulate the binder course mortar material response when subjected to indirect tensile loading. A uniaxial tensile test and a three-point bend test were employed to determine initial stress-strain curves at different test rates and the cohesive zone parameters (specifically, fracture energy and cohesive strength). Numerical results agree well with the experimental data up to the peak load and onset of fracture, demonstrating the value of the cohesive zone modelling technique in successfully predicting fracture initiation and maximum material strength.
ABSTRACT Cold-mix bituminous materials offer a sustainable, cost effective alternative to traditi... more ABSTRACT Cold-mix bituminous materials offer a sustainable, cost effective alternative to traditional hot-mixes. Difficulties however can be encountered when specifying cold-mix materials due to the strong influence of time and temperature on material performance. In the field of concrete technology maturity methods are routinely used for assessing materials of known curing history. This research presents the development of a maturity approach for the assessment of cold-mix bituminous materials and its application for predicting the effect of climatic variations on in situ mixture performance. A strong correlation was observed between the calculated maturity and the measured stiffness for a range of conditioning temperatures and durations thus enabling the prediction of long and short-term material performance in situ where ambient conditions are known.
Page 1. Abstract for COMPTEST conference, Porto, April 2006 DEVELOPMENT OF A COMBINED MICROMECHAN... more Page 1. Abstract for COMPTEST conference, Porto, April 2006 DEVELOPMENT OF A COMBINED MICROMECHANICS & DAMAGE MECHANICS MODEL FOR THE DESIGN OF ASPHALT PAVEMENTS A. Tabaković1,2, C. McNally1, LG Sorelli1, A. Gibney1, MD Gilchrist2* ...
ABSTRACT: This paper presents the results of ongoing research on the mechanical performance of a ... more ABSTRACT: This paper presents the results of ongoing research on the mechanical performance of a 20mm binder course asphalt pavement mix incorporating recycled asphalt pavement (RAP). A series of binder course mixes were designed containing varying percentages of ...
ABSTRACT There is a need for a method for assessing the results from changes in the potential dur... more ABSTRACT There is a need for a method for assessing the results from changes in the potential durability of road materials due to the inclusion of reclaimed and secondary component materials in the manufacture of new road materials. Such changes will have an effect on the cost of the construction maintenance, both financially to the client and environmentally to society in general, and any savings may be transitory. A site trial has been laid of mixtures with and without reclaimed asphalt and work started to assess their durability from early-life properties. The trials are being monitored for their initial performance whilst laboratory trials are concentrating on the combined effect of ageing and moisture damage on the performance of asphalt mixtures on the trial. All three strands are being used to develop life-cycle analysis models to customize them for the effect of using alternative component materials on the availability of the network and their overall financial and environmental cost, both initial and whole-life. The costs will be identified as being direct (of the construction and maintenance) and indirect (on society in general, such as congestion).
This paper investigates the applicability of a cohesive zone model for simulating the performance... more This paper investigates the applicability of a cohesive zone model for simulating the performance of bituminous material subjected to quasi-static loading. The Dugdale traction law was implemented within a finite volume code in order to simulate the binder course mortar material response when subjected to indirect tensile loading. A uniaxial tensile test and a three-point bend test were employed to determine initial stress-strain curves at different test rates and the cohesive zone parameters (specifically, fracture energy and cohesive strength). Numerical results agree well with the experimental data up to the peak load and onset of fracture, demonstrating the value of the cohesive zone modelling technique in successfully predicting fracture initiation and maximum material strength.
This paper presents the results of ongoing research on the mechanical performance of a 20mm binde... more This paper presents the results of ongoing research on the mechanical performance of a 20mm binder course asphalt pavement mix incorporating recycled asphalt pavement (RAP). A series of binder course mixes were designed containing varying percentages of RAP. A mix made only from virgin material was selected as the control mix for the investigation. The effect of introducing RAP into the binder course mix was evaluated through a series of laboratory tests including the Marshall Test, Indirect Tensile Stiffness Modulus Test, Indirect Tensile Fatigue Test and Water Sensitivity Test. A Circular Wheel Track (CWT) was developed in order to study the dynamic effects of a rolling wheel travelling over an asphalt pavement. The CWT was commissioned within a temperature controlled room along with a customised Data Acquisition (DAQ) system. The system involves the testing of rectangular slabs and allows for the investigation of the dynamic tensile strain. The dynamic tensile strain is digitally recorded and the loading effect assessed. The laboratory tests have shown that the introduction of RAP to the binder course mix resulted in an improvement in all mechanical properties. This was also observed in the dynamic tensile strain test.
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