La determination rapide des composes complexes d'hydrocarbures aromatiques poly-cycliques (HA... more La determination rapide des composes complexes d'hydrocarbures aromatiques poly-cycliques (HAP) dans les granulats de debris bitumineux (GDB) requiert des techniques sophistiquees de discrimination (p.e. HPLC, GC-MS, ...). La presence de HAP est due au fait que, dans le passe, le secteur routier faisait usage de produits goudronneux. Les fortes concentrations de HAP et leurs proprietes cancerigenes excluent toutefois le recyclage a chaud des GDB contenant du goudron. Il est des lors crucial pour les entrepreneurs, les producteurs d'enrobes ou les centres de recyclage de pouvoir distinguer clairement les materiaux contenant du goudron de ceux qui en sont exempts. (Marker , chroma-tographie sur papier, essai a la tache, ...) pour mettre en evidence la presence de goudron dans les GDB. Les avantages et inconvenients de ces methodes qualitatives ont ete illustres, ainsi que leurs limites de detection. Dans une seconde phase on se penche sur le developpement d'une nouvelle me...
PROCEEDINGS OF THE 4TH EURASPHALT AND EUROBITUME CONGRESS HELD MAY 2008, COPENHAGEN, DENMARK, 2008
On the E19 motorway between Brussels and Antwerp, large test sections containing nine different h... more On the E19 motorway between Brussels and Antwerp, large test sections containing nine different high-modulus asphalt base courses and one asphalt concrete base course were constructed in April 2006. This paper presents the results of the laboratory research program, which preceded the construction. The first goal of the laboratory research was the selection of the variants to be applied on the test sections. The variants cover two types of aggregate grading (one with sand skeleton and another with stone skeleton), four types of binders, the use of reclaimed asphalt and different binder contents. The second goal was to study the impact of mix design and material properties on the performance of high modulus asphalt. Workability, compactibility, resistance to permanent deformation, high stiffness, good fatigue life and limited water sensitivity were considered as the essential requirements for a long life durable base course. Performance related laboratory tests were carried out to verify these requirements. This paper discusses test results, draws conclusions on the impact of material characteristics and mix design on performance and hence provides important knowledge related to the design of high modulus asphalt mixes. For the covering abstract see ITRD E157233
PROCEEDINGS OF THE 4TH EURASPHALT AND EUROBITUME CONGRESS HELD MAY 2008, COPENHAGEN, DENMARK, 2008
Within the framework of European test methods, the determination of the indirect tensile strength... more Within the framework of European test methods, the determination of the indirect tensile strength ratio (ITSR) is put forward as a measure in order to assess the water sensitivity of asphalt mixtures. During the last 2 years, the Belgian Road Research Centre in collaboration with the Flemish Administration - Department of Mobility and Public Works has evaluated the ITSR test to predict the potential susceptibility of asphalt mixtures to water damage and associated pavement distresses such as surface ravelling. The main objective of the study is to investigate the relationship between the performance in the field and the ITSR values measured in the laboratory. This validation study should allow the establishment of the credibility of the test method and therefore provide the basis for performance related specifications. Test results related to the test sections containing nine different high modulus base courses constructed in 2006 on the heavily trafficked E19 motorway between Brussels and Antwerp are discussed, as well as a series of road works which included the application of stone mastic asphalt (SMA). For the covering abstract see ITRD E157233
Producing and paving asphalt at lowered temperatures, by adding chemical additives, creates some ... more Producing and paving asphalt at lowered temperatures, by adding chemical additives, creates some important benefits: reduced energy consumption, reduced emission of harmful gasses, increased comfort for road workers, less oxidation of the bitumen resulting in better durability. This so called warm mix asphalt can only be allowed if the performance characteristics of the pavement are not worse than those of the classic hot mix asphalt.In this research, three additives are tested on a frequently used asphalt concrete (AC 0/10), specified in the tender specifications of the Flemish region. DSR (Dynamic Shear Rheometer), R&B (Ring & Ball) temperature and Pen (Penetration) are measured on the bitumen-additive blend. Gyratory compaction, wheel tracking and ITSR (Indirect Tensile Strength Ratio) tests are performed on the asphalt mix.
The work presented in this paper describes the research activities of the task group ‘Properties ... more The work presented in this paper describes the research activities of the task group ‘Properties of filler aggregates’ with respect to the durability of Stone Mastic Asphalt (SMA) mixtures, which was conducted recently at the Belgian Road Research Centre. The main objective of this study comprises the effect of hydrated lime on the durability of SMA mixtures. The methodology developed in this study includes in an initial phase the design in the laboratory of a ‘critical’ SMA10 mixture. Such a ‘critical’ SMA10 mixture was considered to be characterised by a high water sensitivity and, therefore, a low durability. During this process, attention was paid to both the SMA composition as well as to the compaction energy applied in order to provide suitable test samples. Subsequently, by making use of such a ‘critical’ SMA10 mixture, the effect of the filler nature on the durability of the SMA mixtures was established; in particular both the modification by as well as the optimal content of hydrated lime was studied. Additionally, the possible effect of hydrated lime on the workability of latter SMA mixtures was investigated. Finally, the results obtained in the laboratory were complemented by a field study and a monitoring campaign. This survey comprises the evaluation of the impact of hydrated lime on the compactibility and the water sensitivity on test sections as well as a yearly follow up of the performance of a series of SMA10 mixtures varying in the type of filler material used.
The "Properties of Filler Aggregates" task group's research activities, conducted r... more The "Properties of Filler Aggregates" task group's research activities, conducted recently at the Belgian Road Research Centre, are presented in this paper. The task group's main objectives included investigation of filler aggregate characteristics, requirements fillers need to meet, and possible introduction of test methods capable of ensuring constant hot mix asphalt filler quality and performance. In the study's first step, there was assessment of properties of a large number of filler aggregates obtained through natural and/or recycled or manufactured material processing, through which important information was yielded about characteristic possible variability or constancy over an approximately two month production period. Research during this initial phase concentrated on filler properties linked to European standard EN 13043 specifications. Following mastics manufacture, the stiffening properties of fillers subsequently were investigated through "Delta Ring and Ball" softening temperature determination and viscosity at 60 C by DSR. With respect to asphalt mix filler performance, there was anticipation that useful information could be provided through the latter test. Finally, there was exploration of the possible impact of filter material on asphalt mix performance through Marshall characteristic measurements of an AC-14 binder course. Moreover, the latter asphalt mixes' water sensitivity were evaluated through a series of retained Marshall experiments.
Coloured asphalt pavements are increasingly used in large public areas and at dangerous intersect... more Coloured asphalt pavements are increasingly used in large public areas and at dangerous intersections such as crossroads, roundabouts or pedestrian crossings. In the former application, the role of the coloured pavement is often to give the space a particular aesthetic character or to integrate it well in its surroundings; in the latter, its major role is to enhance the safety of users by improving visibility and road legibility. However, coloured pavements are also subjected to traffic and climate-induced stresses and must, therefore, exhibit a similar mechanical performance as their uncoloured counterparts. Desired colours are obtained by using specific materials such as coloured aggregates, pigments and clear binders. However, the application of latter constituents may affect the performance and durability of coloured asphalt mixtures. Therefore, in a first step, BRRC (Belgian Road Research Centre) determined the characteristics of these particular materials such as the rheological behaviour of clear binders both at high and low temperatures and the stiffening effect of pigments acting as filler. Subsequently, the impact of the material characteristics on volumetric mix design was investigated. In a next phase their effect on the mechanical performance of coloured mixtures was studied in the laboratory. The latter performance was evaluated by testing for water sensitivity, rutting resistance and low-temperature cracking. This contribution summarizes the major findings from the study.
In Belgium, the commonly used test method for the determination of the binder content of a bitumi... more In Belgium, the commonly used test method for the determination of the binder content of a bituminous mixture is based on the extraction of the soluble bitumen with a centrifuge. This step is followed by a recovery of the solvent with a rotary evaporator when the binder is yet to be characterized. The procedures for pure binders are clearly described
La determination rapide des composes complexes d'hydrocarbures aromatiques poly-cycliques (HA... more La determination rapide des composes complexes d'hydrocarbures aromatiques poly-cycliques (HAP) dans les granulats de debris bitumineux (GDB) requiert des techniques sophistiquees de discrimination (p.e. HPLC, GC-MS, ...). La presence de HAP est due au fait que, dans le passe, le secteur routier faisait usage de produits goudronneux. Les fortes concentrations de HAP et leurs proprietes cancerigenes excluent toutefois le recyclage a chaud des GDB contenant du goudron. Il est des lors crucial pour les entrepreneurs, les producteurs d'enrobes ou les centres de recyclage de pouvoir distinguer clairement les materiaux contenant du goudron de ceux qui en sont exempts. (Marker , chroma-tographie sur papier, essai a la tache, ...) pour mettre en evidence la presence de goudron dans les GDB. Les avantages et inconvenients de ces methodes qualitatives ont ete illustres, ainsi que leurs limites de detection. Dans une seconde phase on se penche sur le developpement d'une nouvelle me...
PROCEEDINGS OF THE 4TH EURASPHALT AND EUROBITUME CONGRESS HELD MAY 2008, COPENHAGEN, DENMARK, 2008
On the E19 motorway between Brussels and Antwerp, large test sections containing nine different h... more On the E19 motorway between Brussels and Antwerp, large test sections containing nine different high-modulus asphalt base courses and one asphalt concrete base course were constructed in April 2006. This paper presents the results of the laboratory research program, which preceded the construction. The first goal of the laboratory research was the selection of the variants to be applied on the test sections. The variants cover two types of aggregate grading (one with sand skeleton and another with stone skeleton), four types of binders, the use of reclaimed asphalt and different binder contents. The second goal was to study the impact of mix design and material properties on the performance of high modulus asphalt. Workability, compactibility, resistance to permanent deformation, high stiffness, good fatigue life and limited water sensitivity were considered as the essential requirements for a long life durable base course. Performance related laboratory tests were carried out to verify these requirements. This paper discusses test results, draws conclusions on the impact of material characteristics and mix design on performance and hence provides important knowledge related to the design of high modulus asphalt mixes. For the covering abstract see ITRD E157233
PROCEEDINGS OF THE 4TH EURASPHALT AND EUROBITUME CONGRESS HELD MAY 2008, COPENHAGEN, DENMARK, 2008
Within the framework of European test methods, the determination of the indirect tensile strength... more Within the framework of European test methods, the determination of the indirect tensile strength ratio (ITSR) is put forward as a measure in order to assess the water sensitivity of asphalt mixtures. During the last 2 years, the Belgian Road Research Centre in collaboration with the Flemish Administration - Department of Mobility and Public Works has evaluated the ITSR test to predict the potential susceptibility of asphalt mixtures to water damage and associated pavement distresses such as surface ravelling. The main objective of the study is to investigate the relationship between the performance in the field and the ITSR values measured in the laboratory. This validation study should allow the establishment of the credibility of the test method and therefore provide the basis for performance related specifications. Test results related to the test sections containing nine different high modulus base courses constructed in 2006 on the heavily trafficked E19 motorway between Brussels and Antwerp are discussed, as well as a series of road works which included the application of stone mastic asphalt (SMA). For the covering abstract see ITRD E157233
Producing and paving asphalt at lowered temperatures, by adding chemical additives, creates some ... more Producing and paving asphalt at lowered temperatures, by adding chemical additives, creates some important benefits: reduced energy consumption, reduced emission of harmful gasses, increased comfort for road workers, less oxidation of the bitumen resulting in better durability. This so called warm mix asphalt can only be allowed if the performance characteristics of the pavement are not worse than those of the classic hot mix asphalt.In this research, three additives are tested on a frequently used asphalt concrete (AC 0/10), specified in the tender specifications of the Flemish region. DSR (Dynamic Shear Rheometer), R&B (Ring & Ball) temperature and Pen (Penetration) are measured on the bitumen-additive blend. Gyratory compaction, wheel tracking and ITSR (Indirect Tensile Strength Ratio) tests are performed on the asphalt mix.
The work presented in this paper describes the research activities of the task group ‘Properties ... more The work presented in this paper describes the research activities of the task group ‘Properties of filler aggregates’ with respect to the durability of Stone Mastic Asphalt (SMA) mixtures, which was conducted recently at the Belgian Road Research Centre. The main objective of this study comprises the effect of hydrated lime on the durability of SMA mixtures. The methodology developed in this study includes in an initial phase the design in the laboratory of a ‘critical’ SMA10 mixture. Such a ‘critical’ SMA10 mixture was considered to be characterised by a high water sensitivity and, therefore, a low durability. During this process, attention was paid to both the SMA composition as well as to the compaction energy applied in order to provide suitable test samples. Subsequently, by making use of such a ‘critical’ SMA10 mixture, the effect of the filler nature on the durability of the SMA mixtures was established; in particular both the modification by as well as the optimal content of hydrated lime was studied. Additionally, the possible effect of hydrated lime on the workability of latter SMA mixtures was investigated. Finally, the results obtained in the laboratory were complemented by a field study and a monitoring campaign. This survey comprises the evaluation of the impact of hydrated lime on the compactibility and the water sensitivity on test sections as well as a yearly follow up of the performance of a series of SMA10 mixtures varying in the type of filler material used.
The "Properties of Filler Aggregates" task group's research activities, conducted r... more The "Properties of Filler Aggregates" task group's research activities, conducted recently at the Belgian Road Research Centre, are presented in this paper. The task group's main objectives included investigation of filler aggregate characteristics, requirements fillers need to meet, and possible introduction of test methods capable of ensuring constant hot mix asphalt filler quality and performance. In the study's first step, there was assessment of properties of a large number of filler aggregates obtained through natural and/or recycled or manufactured material processing, through which important information was yielded about characteristic possible variability or constancy over an approximately two month production period. Research during this initial phase concentrated on filler properties linked to European standard EN 13043 specifications. Following mastics manufacture, the stiffening properties of fillers subsequently were investigated through "Delta Ring and Ball" softening temperature determination and viscosity at 60 C by DSR. With respect to asphalt mix filler performance, there was anticipation that useful information could be provided through the latter test. Finally, there was exploration of the possible impact of filter material on asphalt mix performance through Marshall characteristic measurements of an AC-14 binder course. Moreover, the latter asphalt mixes' water sensitivity were evaluated through a series of retained Marshall experiments.
Coloured asphalt pavements are increasingly used in large public areas and at dangerous intersect... more Coloured asphalt pavements are increasingly used in large public areas and at dangerous intersections such as crossroads, roundabouts or pedestrian crossings. In the former application, the role of the coloured pavement is often to give the space a particular aesthetic character or to integrate it well in its surroundings; in the latter, its major role is to enhance the safety of users by improving visibility and road legibility. However, coloured pavements are also subjected to traffic and climate-induced stresses and must, therefore, exhibit a similar mechanical performance as their uncoloured counterparts. Desired colours are obtained by using specific materials such as coloured aggregates, pigments and clear binders. However, the application of latter constituents may affect the performance and durability of coloured asphalt mixtures. Therefore, in a first step, BRRC (Belgian Road Research Centre) determined the characteristics of these particular materials such as the rheological behaviour of clear binders both at high and low temperatures and the stiffening effect of pigments acting as filler. Subsequently, the impact of the material characteristics on volumetric mix design was investigated. In a next phase their effect on the mechanical performance of coloured mixtures was studied in the laboratory. The latter performance was evaluated by testing for water sensitivity, rutting resistance and low-temperature cracking. This contribution summarizes the major findings from the study.
In Belgium, the commonly used test method for the determination of the binder content of a bitumi... more In Belgium, the commonly used test method for the determination of the binder content of a bituminous mixture is based on the extraction of the soluble bitumen with a centrifuge. This step is followed by a recovery of the solvent with a rotary evaporator when the binder is yet to be characterized. The procedures for pure binders are clearly described
Uploads
Papers by Stefan Vansteenkiste