alan carter | École de Technologie Supérieure (original) (raw)
Papers by alan carter
Materials and Structures
This paper describes the development of novel/state-of-art computational framework to accurately ... more This paper describes the development of novel/state-of-art computational framework to accurately predict the degree of binder activity of a reclaimed asphalt pavement sample as a percentage of the indirect tensile strength (ITS) using a reduced number of input variables that are relatively easy to obtain, namely compaction temperature, air voids and ITS. Different machine learning (ML) techniques were applied to obtain the most accurate data representation model. Specifically, three ML techniques were applied: 6th-degree multivariate polynomial regression with regularization, artificial neural network and random forest regression. The three techniques produced models with very similar precision, reporting a mean absolute error ranging from 12.2 to 12.8% of maximum ITS on the test data set. The work presented in this paper is an evolution in terms of data analysis of the results obtained within the interlaboratory tests conducted by Task Group 5 of the RILEM Technical Committee 264 o...
RILEM Bookseries, 2018
Performance grade system for bitumen characterization is used to ensure that the selected bitumen... more Performance grade system for bitumen characterization is used to ensure that the selected bitumen has the required properties for the environmental conditions found in-situ. However, it has been shown that within a given PG grade, the properties can differ thru time. In this study the rheological characteristics evaluated with a DSR and a BBR are compared with the chemical composition of two different bitumen produced from different crude oil but with the same PG grade. The results have shown that even if both bitumens performs similarly with the usual ageing, RTFO and PAV, their characteristics get more different with intensive artificial laboratory ageing. The chemical characteristics of the bitumens were measured with infrared spectroscopy. It was shown that the change of their chemical composition with ageing is different. The links between their rheological properties and their chemical characteristics measured with FTIR that have been found is different for both bitumens.
Nowadays, it is common to add a little amount of Reclaimed Asphalt Pavement (RAP) in asphalt mixe... more Nowadays, it is common to add a little amount of Reclaimed Asphalt Pavement (RAP) in asphalt mixes without changing too much properties such as modulus and low temperature cracking resistance. Not only will those mixes be able to make roads last longer, but they will be a greener alternative to usual mixes. In order to make a flexible pavement design, the mixture behavior is usually characterized with the complex modulus. To have a high modulus mix, you need to control the gradation precisely even when RAP is added. When performing a mix design to incorporate RAP, it is desirable to know the RAP binder characteristics and content and its gradation. In the literature, there is no clear vision of the RAP gradation impacts on the mixture properties and field performance. The objective of this study, performed at the Pavements and Bituminous Materials Laboratory (LCMB), is to evaluate the impact of RAP gradation on Hot Mix Asphalt. This is needed to understand how much binder can be transferred during mix from RAP to virgin aggregate. In this study, a single source of RAP was separated into different sizes and mixed with a specific group of virgin aggregates. Then, according to their size, the mixes were separated again into the RAP group and virgin aggregate. While these were mixed, active RAP binder transferred to virgin aggregate. Then ignition test (ASTM D6307) was adapted to separate RAP binder from virgin aggregate. With this procedure, it was possible to see that, for a given temperature and mixing time, activated binder amount of coarse RAP particles and fine RAP particles. The Ignition test result showed that coarse RAP particles have more active binder in mix but ITS test indicated that fine RAP particles have higher strength.
Case Studies in Construction Materials, 2021
Rubberized asphalt is known for its elastic deformation recovery and good resilience in response ... more Rubberized asphalt is known for its elastic deformation recovery and good resilience in response to loads owing to the elastic characteristics of tire rubber powder. There are several methods for the prediction of the stiffness modulus of asphalt mixtures. However, there are limited studies on predicting the stiffness modulus incorporating both wet and dry rubberization methods based on the available methods of Asphalt Institute (AI) and IDOT (Illinois department of transportation). In this research, Stone Mastic Asphalt (SMA) mixtures were modified with truck tire rubber powder (TRP) with two different processes: SMA-WP (SMA mixtures modified in the wet process) and SMA-DP (SMA mixtures modified in the dry process). In both methods, 3%, 6%, and 9% of TRP were used for modification, and the performance of the control and modified mixtures was evaluated under indirect tensile strength (ITS) and indirect tensile stiffness modulus (ITSM) tests. Finally, the results of ITSM were compared to predicted resilient modulus based on the Asphalt Institute (AI) and Illinois Department of Transportation (IDOT). The experiments revealed that SMA-DP mixes have higher ITS than SMA-WP. At the same time, both methods showed a decrease in ITS as TRP content increases. Furthermore, the SMA-WP samples showed a lower phase angle than SMA-DP samples, indicating higher elasticity for the mixtures. In addition, SMA-WP showed lower horizontal deformation than SMA-DP, which helps reduce rutting on the surface layer. Finally, the prediction results showed that the IDOT method could not predict the Stiffness Modulus, while the AI method was more accurate and can be used for prediction.
Materials, 2020
Creep compliance (D(t)) is a very important input for the thermal cracking resistance in the Mech... more Creep compliance (D(t)) is a very important input for the thermal cracking resistance in the Mechanistic-Empirical Pavement Design Guide (MEPDG). The aim of the work presented here is to predict the results of creep compliance D(t) from the result of complex modulus E*(ω). The work plan is divided in two main parts: an experimental part consisting of creep tests, and a modeling part. Three configurations were compared together, namely direct tensile, direct compression and indirect tensile tests. The modelling part consists of using a 2S2P1D model coupled to Kopelman approximation to switch from the frequency domain to the time domain. Additionally, 2S2P1D was used to calibrate the generalized Kelvin–Voigt model and get the creep compliance directly from E* results. The experimental results show that D(t) from direct tensile and direct compression are the same in the viscoelastic domain and are greater than D(t) from the indirect tensile test. The indirect tensile test (IDT) seems t...
Infrastructures, 2019
Utilizing recycled asphalt pavements (RAP) in pavement construction is known as a sustainable app... more Utilizing recycled asphalt pavements (RAP) in pavement construction is known as a sustainable approach with significant economic and environmental benefits. While studying the effect of high RAP contents on the performance of hot mix asphalt (HMA) mixes has been the focus of several research projects, limited work has been done on studying the effect of RAP fraction and particle size on the overall performance of high RAP mixes produced solely with either coarse or fine RAP particles. To this end, three mixes including a conventional control mix with no RAP, a fine RAP mix (FRM) made with 35% percent fine RAP, and a coarse RAP mix (CRM) prepared with 54% of coarse RAP were designed and investigated in this study. These mixes were evaluated with respect to their rutting resistance, fatigue cracking resistance, and low temperature cracking performance. The results indicate that although the CRM had a higher RAP content, it exhibited better or at least the same performance than the FRM...
Journal of Traffic and Transportation Engineering (English Edition), 2019
h i g h l i g h t s Cold temperature curing reduces ITS of CRM treated with foam or emulsion. CRM... more h i g h l i g h t s Cold temperature curing reduces ITS of CRM treated with foam or emulsion. CRM treated with emulsion are more sensitive to cure temperature than CRM treated with foamed asphalt. A secondary cure at room temperature has limited impact on ITS for emulsion treated CRM that were first cured at 0 C.
Infrastructures, 2019
In the current era of road construction, it is common to add a small amount of reclaimed asphalt ... more In the current era of road construction, it is common to add a small amount of reclaimed asphalt pavement (RAP) in asphalt mixes without significantly changing properties such as stiffness and low-temperature cracking resistance. Not only can these mixes be better for the environment, but they can also improve certain properties like rutting resistance. However, there is no clear understanding of how RAP gradation and bitumen properties impact the mixture properties. In this study, a single RAP source was separated into coarse and fine particles and added into a hot mix asphalt (HMA). Fourier transform infrared (FTIR) spectrometry was used to evaluate the chemical properties of the bitumen, while environmental scanning electron microscopy (ESEM) image analysis was used to visualize the differences of the virgin and RAP bitumen at a microscopic level. The observed results indicated that the recovered bitumen from coarse RAP did not have the same characteristics as the fine RAP bitume...
Proceedings of 6th Eurasphalt & Eurobitume Congress, 2016
Full Depth Reclamation (FDR) and Cold In-Place Recycling (CIR) are popular rehabilitation techniq... more Full Depth Reclamation (FDR) and Cold In-Place Recycling (CIR) are popular rehabilitation techniques for flexible pavement. Both techniques can be done with the addition of asphalt emulsion or foamed bitumen as a stabilizer. In most cases, those two techniques to add bitumen are considered equivalent, even if the way they give cohesion to the mix is different. A research project was undertaken to verify the possibility of using both asphalt emulsion and foamed bitumen on FDR materials to have better mechanical characteristics since it's believed that asphalt emulsion gives a good coating, and foamed asphalt does not coat as well but serves as a binding agent. FDR mixes were prepared in the laboratory with and without asphalt emulsion and foamed bitumen. Different addition processes were tested in order to find the optimum mix design procedure. Moisture susceptibility tests (Marshall tests and indirect tension tests) and complex modulus tests were performed on the different mixes, and it was shown that the use of both binders can give you a mix with better performance. This paper presents the mix design, the test program and the results of this study.
Bulletin Des Laboratoires Des Ponts Et Chaussees, 2007
Thesis (Ph. D.)--Auburn University, 2005. Abstract. Includes bibliographical references (leaves 8... more Thesis (Ph. D.)--Auburn University, 2005. Abstract. Includes bibliographical references (leaves 82-87).
International Journal on Pavemnet Engineering & Asphalt Technology, 2013
Micro-Surfacing is a polymer modified, binder emulsion based, dense graded, cold mixed, and quick... more Micro-Surfacing is a polymer modified, binder emulsion based, dense graded, cold mixed, and quick setting, asphalt resurfacing material. Type III application of microsurfacing is used as the rut fill materials for highly trafficked roads. As of now, International Slurry Surfacing Association (ISSA) mix design guideline is the widely used standard to design micro-surfacing mixtures. The research described in this paper intended to suggest modifications to the actual ISSA mix design procedure to accurately select aggregate grading for type III micro-surfacing mixtures. To do this, a sensitivity analysis was performed in order to study the effect of aggregate gradation, and binder emulsion residue on five micro-surfacing mixture design tests, including Loaded wheel test (ISSA TB 109), Wet track abrasion test (ISSA TB 100), modified cohesion test (ISSA TB 139), vertical displacement test (ISS TB 109, Method-A), and Mixing time test (ISSA TB 113). The second part of study consisted mainly of establishing a limit for the aggregate gradation used in type III application of micro-surfacing, which gives higher resistance to rutting as it is the main property of type III micro-surfacing. In order to do this, the resistant of different micro-surfacing mixtures against rutting was evaluated, and modified specifications were suggested to select aggregate grading for type III microsurfacing.
Bituminous Mixtures and Pavements VI, 2015
The increase in the use of Reclaimed Asphalt Pavement (RAP) makes it necessary to focus on the in... more The increase in the use of Reclaimed Asphalt Pavement (RAP) makes it necessary to focus on the interaction between the old and the virgin binders represented by the so-called blending chart. Different types of linear binder blending chart are currently available to predict the characteristics of the final blend. This study constitutes part of a wider research campaign whose aim it is to provide prediction models for the rheological properties of RAP, taking into account a selection of variables that cause its heterogeneity. The objective of this paper is to provide a multiple regression model at medium and high temperatures for the prediction of the complex modulus and phase angle of binder blends. The models consider more than one variable at the same time: the type of virgin and aged binders, the percentage of aged binder, the loading frequency and the temperature. Thus, within a specific validity range based on the extreme values defined by the experimental domain, it is possible to predict the rheological properties of the binder blends, and to carry out a sensitivity analysis on the effects of each parameter.
Canadian Journal of Civil Engineering, 2015
Although Micro-surfacing is widely used, current tests and mix design methods mostly rely on labo... more Although Micro-surfacing is widely used, current tests and mix design methods mostly rely on laboratory condition and the correlation between laboratory results and field performance is poor. Therefore, there is a need to develop new mix design procedures, specifications, and guidelines for Micro-surfacing. The research described in this thesis intended to review the current mix design procedures for Slurry Seal and Micro-surfacing and suggest modifications to the actual International Slurry Seal Association (ISSA) mix design procedure for microsurfacing as a high performance surface treatment and pavement preservation method. The first part of study reports the findings of a detailed laboratory investigation concerning the effect of asphalt emulsion, added water content, and the use of additives (Portland cement) on the design parameters and properties of micro-surfacing mixtures. For this, one aggregate type, one asphalt emulsion type/grade, and one aggregate gradation were used in the study. The evaluation was conducted at one curing stages of the mix (24-Hours). Three levels of asphalt emulsion, four levels of added water content, and one level of Portland cement were used in order to evaluate role of asphalt emulsion, water, and cement. This part of study consisted mainly of establishing a method for preparing and testing micro-surfacing mixture using four main mixture design tests proposed by the ISSA (TB 139, TB 113, TB 100, and TB 109). The results obtained with ISSA TB 109 and ISSA TB 100 mixture design tests were found highly variable and not precise enough to suggest optimum mix design. For the second part of this study, different tests were also studied in order to refine the current mix design procedure. The results have shown that ISSA TB 139 can be used to define the optimum water content at which samples should be tested, and that ISSA TB 147 mix design test should be used to define the optimum asphalt emulsion content.
Transportation Research Record, 2005
Ride quality assessed with an inertial profiler on flexible pavement was used to provide initial ... more Ride quality assessed with an inertial profiler on flexible pavement was used to provide initial information on the following key issues: repeata-bility associated with international roughness index (IRI) values for a wide range of hot-mix asphalt (HMA) material variables, timing of ...
Materials and Structures, 2014
Journal of Transportation Engineering, 2007
ABSTRACT Statistical analyses of over 2,000 pavement designs using the 1993 American Association ... more ABSTRACT Statistical analyses of over 2,000 pavement designs using the 1993 American Association of State Highway Transportation Officials Design Guide was conducted. Variations in traffic levels, and subgrade, base, and hot mix asphalt (HMA) moduli and thickness showed that the only significant material and traffic design inputs were the subgrade modulus and the initial ESAL loads. A plus or minus 5% change in the design traffic level did not statistically influence the determination of the structural number (SN). A subgrade modulus of 3,000 psi and a linear growth rate of 4% for roadways with annual average daily traffic of more than 10,000 is recommended for determining the SN. The growth rate for lower traffic volume roadways will vary significantly between 0 and 3%. A more limited evaluation of the 2002 Design Guide showed that a mechanistic-empirical method of flexible pavement design is strongly influenced by the HMA thickness and the distribution of truck types within the annual average daily traffic. Selecting the appropriate roadway functional classification defines the default percent of traffic that is comprised of trucks and is important to the program output. Performance data for two Alabama long-term pavement performance sections was used to verify both design methods.
Canadian Journal of Civil Engineering, 2002
In an attempt to apply the concepts developed by Carman and Klinkenberg for the measurement of pe... more In an attempt to apply the concepts developed by Carman and Klinkenberg for the measurement of permeability of a porous media using a gas, a permeameter for the in-situ measurement of intrinsic permeability of skin concrete has been developed. The established technique allows concentration of gas percolation through a well-defined zone in the superficial layer of concrete. The instrument, the measurement method, and the calculation procedure are described in details in this paper. Several series of tests have been performed in laboratory on concrete blocks (300 × 300 × 400 mm) to simulate measurements on the construction site. Three types of concrete, with different porosity, have been tested. The measurement of permeability performed on the concrete blocks have been accomplished both on shaped surfaces, which are representative of skin concrete, and on sawed surfaces, which are representative of mass concrete. Results show that the relationship between the water/cement ratio and th...
Australian Journal of Civil Engineering, 2013
ABSTRACT The first part of this study evaluates the repeatability of the International Slurry Sur... more ABSTRACT The first part of this study evaluates the repeatability of the International Slurry Surfacing Association (ISSA) mixture design tests. Consistency of test results between two laboratories (MTQ and LCMB) and within material combinations was evaluated. Aggregate gradation and sample preparation method were varied, and the responses for various ISSA mix design test for micro-surfacing were examined. The repeatability of four ISSA mix design tests for micro-surfacing was computed. To do this, the micro-surfacing mixtures were prepared by four technicians at two laboratories in Quebec. Modified cohesion test, wet track abrasion test, loaded wheel test, and resistance to compaction test were those evaluated in this study. The effect of sample preparation method using aggregate splitting and sieve analysis on consistency of mixture design test results was also evaluated in this part of study. It was observed that employing sieve analysis method for micro-surfacing mixture preparation yields the more consistence test responses. For the second part of this study, the role of aggregate gradation, and their total surface area on cohesion, resistance to abrasion, and resistance to permanent deformation of micro-surfacing mixtures was studied. Two different type III applications of micro-surfacing mixtures which are used as rut-fill materials in highly traffic area were selected to determine the effects of aggregate total surface area on micro-surfacing mix design test responses. It was found that the micro-surfacing mixtures prepared using aggregate gradation with more fine aggregates have higher resistance to rutting, bleeding, abrasion, moisture susceptibility, and early rolling traffic.
Colored asphalt materials are gaining more attention in the European market due to their architec... more Colored asphalt materials are gaining more attention in the European market due to their architectural/aesthetic prospective and their effect as a signal on the road. Especially in Netherlands this technology has gained popularity and is currently used for red bicycle lanes for example. Micro-surfacing mixture, as a pavement preservation and surface treatment method, is typically made with bitumen base mixes predominantly composed of virgin aggregates, and quick setting polymer modified bitumen emulsions. In order to study the feasibility of formulating colored micro-surfacing mixtures with increased durability, research was conducted at Latexfalt B.V. in The Netherlands in collaboration with Laboratoire sur les Chaussées et Matériaux Bitumineux (LCMB), at École de technologie supérieure (ÉTS) in Canada. The first part of the study examined the possibility of producing coloured micro-surfacing mixtures by using clear binder modified with different types of polymer. The goal was to c...
Materials and Structures
This paper describes the development of novel/state-of-art computational framework to accurately ... more This paper describes the development of novel/state-of-art computational framework to accurately predict the degree of binder activity of a reclaimed asphalt pavement sample as a percentage of the indirect tensile strength (ITS) using a reduced number of input variables that are relatively easy to obtain, namely compaction temperature, air voids and ITS. Different machine learning (ML) techniques were applied to obtain the most accurate data representation model. Specifically, three ML techniques were applied: 6th-degree multivariate polynomial regression with regularization, artificial neural network and random forest regression. The three techniques produced models with very similar precision, reporting a mean absolute error ranging from 12.2 to 12.8% of maximum ITS on the test data set. The work presented in this paper is an evolution in terms of data analysis of the results obtained within the interlaboratory tests conducted by Task Group 5 of the RILEM Technical Committee 264 o...
RILEM Bookseries, 2018
Performance grade system for bitumen characterization is used to ensure that the selected bitumen... more Performance grade system for bitumen characterization is used to ensure that the selected bitumen has the required properties for the environmental conditions found in-situ. However, it has been shown that within a given PG grade, the properties can differ thru time. In this study the rheological characteristics evaluated with a DSR and a BBR are compared with the chemical composition of two different bitumen produced from different crude oil but with the same PG grade. The results have shown that even if both bitumens performs similarly with the usual ageing, RTFO and PAV, their characteristics get more different with intensive artificial laboratory ageing. The chemical characteristics of the bitumens were measured with infrared spectroscopy. It was shown that the change of their chemical composition with ageing is different. The links between their rheological properties and their chemical characteristics measured with FTIR that have been found is different for both bitumens.
Nowadays, it is common to add a little amount of Reclaimed Asphalt Pavement (RAP) in asphalt mixe... more Nowadays, it is common to add a little amount of Reclaimed Asphalt Pavement (RAP) in asphalt mixes without changing too much properties such as modulus and low temperature cracking resistance. Not only will those mixes be able to make roads last longer, but they will be a greener alternative to usual mixes. In order to make a flexible pavement design, the mixture behavior is usually characterized with the complex modulus. To have a high modulus mix, you need to control the gradation precisely even when RAP is added. When performing a mix design to incorporate RAP, it is desirable to know the RAP binder characteristics and content and its gradation. In the literature, there is no clear vision of the RAP gradation impacts on the mixture properties and field performance. The objective of this study, performed at the Pavements and Bituminous Materials Laboratory (LCMB), is to evaluate the impact of RAP gradation on Hot Mix Asphalt. This is needed to understand how much binder can be transferred during mix from RAP to virgin aggregate. In this study, a single source of RAP was separated into different sizes and mixed with a specific group of virgin aggregates. Then, according to their size, the mixes were separated again into the RAP group and virgin aggregate. While these were mixed, active RAP binder transferred to virgin aggregate. Then ignition test (ASTM D6307) was adapted to separate RAP binder from virgin aggregate. With this procedure, it was possible to see that, for a given temperature and mixing time, activated binder amount of coarse RAP particles and fine RAP particles. The Ignition test result showed that coarse RAP particles have more active binder in mix but ITS test indicated that fine RAP particles have higher strength.
Case Studies in Construction Materials, 2021
Rubberized asphalt is known for its elastic deformation recovery and good resilience in response ... more Rubberized asphalt is known for its elastic deformation recovery and good resilience in response to loads owing to the elastic characteristics of tire rubber powder. There are several methods for the prediction of the stiffness modulus of asphalt mixtures. However, there are limited studies on predicting the stiffness modulus incorporating both wet and dry rubberization methods based on the available methods of Asphalt Institute (AI) and IDOT (Illinois department of transportation). In this research, Stone Mastic Asphalt (SMA) mixtures were modified with truck tire rubber powder (TRP) with two different processes: SMA-WP (SMA mixtures modified in the wet process) and SMA-DP (SMA mixtures modified in the dry process). In both methods, 3%, 6%, and 9% of TRP were used for modification, and the performance of the control and modified mixtures was evaluated under indirect tensile strength (ITS) and indirect tensile stiffness modulus (ITSM) tests. Finally, the results of ITSM were compared to predicted resilient modulus based on the Asphalt Institute (AI) and Illinois Department of Transportation (IDOT). The experiments revealed that SMA-DP mixes have higher ITS than SMA-WP. At the same time, both methods showed a decrease in ITS as TRP content increases. Furthermore, the SMA-WP samples showed a lower phase angle than SMA-DP samples, indicating higher elasticity for the mixtures. In addition, SMA-WP showed lower horizontal deformation than SMA-DP, which helps reduce rutting on the surface layer. Finally, the prediction results showed that the IDOT method could not predict the Stiffness Modulus, while the AI method was more accurate and can be used for prediction.
Materials, 2020
Creep compliance (D(t)) is a very important input for the thermal cracking resistance in the Mech... more Creep compliance (D(t)) is a very important input for the thermal cracking resistance in the Mechanistic-Empirical Pavement Design Guide (MEPDG). The aim of the work presented here is to predict the results of creep compliance D(t) from the result of complex modulus E*(ω). The work plan is divided in two main parts: an experimental part consisting of creep tests, and a modeling part. Three configurations were compared together, namely direct tensile, direct compression and indirect tensile tests. The modelling part consists of using a 2S2P1D model coupled to Kopelman approximation to switch from the frequency domain to the time domain. Additionally, 2S2P1D was used to calibrate the generalized Kelvin–Voigt model and get the creep compliance directly from E* results. The experimental results show that D(t) from direct tensile and direct compression are the same in the viscoelastic domain and are greater than D(t) from the indirect tensile test. The indirect tensile test (IDT) seems t...
Infrastructures, 2019
Utilizing recycled asphalt pavements (RAP) in pavement construction is known as a sustainable app... more Utilizing recycled asphalt pavements (RAP) in pavement construction is known as a sustainable approach with significant economic and environmental benefits. While studying the effect of high RAP contents on the performance of hot mix asphalt (HMA) mixes has been the focus of several research projects, limited work has been done on studying the effect of RAP fraction and particle size on the overall performance of high RAP mixes produced solely with either coarse or fine RAP particles. To this end, three mixes including a conventional control mix with no RAP, a fine RAP mix (FRM) made with 35% percent fine RAP, and a coarse RAP mix (CRM) prepared with 54% of coarse RAP were designed and investigated in this study. These mixes were evaluated with respect to their rutting resistance, fatigue cracking resistance, and low temperature cracking performance. The results indicate that although the CRM had a higher RAP content, it exhibited better or at least the same performance than the FRM...
Journal of Traffic and Transportation Engineering (English Edition), 2019
h i g h l i g h t s Cold temperature curing reduces ITS of CRM treated with foam or emulsion. CRM... more h i g h l i g h t s Cold temperature curing reduces ITS of CRM treated with foam or emulsion. CRM treated with emulsion are more sensitive to cure temperature than CRM treated with foamed asphalt. A secondary cure at room temperature has limited impact on ITS for emulsion treated CRM that were first cured at 0 C.
Infrastructures, 2019
In the current era of road construction, it is common to add a small amount of reclaimed asphalt ... more In the current era of road construction, it is common to add a small amount of reclaimed asphalt pavement (RAP) in asphalt mixes without significantly changing properties such as stiffness and low-temperature cracking resistance. Not only can these mixes be better for the environment, but they can also improve certain properties like rutting resistance. However, there is no clear understanding of how RAP gradation and bitumen properties impact the mixture properties. In this study, a single RAP source was separated into coarse and fine particles and added into a hot mix asphalt (HMA). Fourier transform infrared (FTIR) spectrometry was used to evaluate the chemical properties of the bitumen, while environmental scanning electron microscopy (ESEM) image analysis was used to visualize the differences of the virgin and RAP bitumen at a microscopic level. The observed results indicated that the recovered bitumen from coarse RAP did not have the same characteristics as the fine RAP bitume...
Proceedings of 6th Eurasphalt & Eurobitume Congress, 2016
Full Depth Reclamation (FDR) and Cold In-Place Recycling (CIR) are popular rehabilitation techniq... more Full Depth Reclamation (FDR) and Cold In-Place Recycling (CIR) are popular rehabilitation techniques for flexible pavement. Both techniques can be done with the addition of asphalt emulsion or foamed bitumen as a stabilizer. In most cases, those two techniques to add bitumen are considered equivalent, even if the way they give cohesion to the mix is different. A research project was undertaken to verify the possibility of using both asphalt emulsion and foamed bitumen on FDR materials to have better mechanical characteristics since it's believed that asphalt emulsion gives a good coating, and foamed asphalt does not coat as well but serves as a binding agent. FDR mixes were prepared in the laboratory with and without asphalt emulsion and foamed bitumen. Different addition processes were tested in order to find the optimum mix design procedure. Moisture susceptibility tests (Marshall tests and indirect tension tests) and complex modulus tests were performed on the different mixes, and it was shown that the use of both binders can give you a mix with better performance. This paper presents the mix design, the test program and the results of this study.
Bulletin Des Laboratoires Des Ponts Et Chaussees, 2007
Thesis (Ph. D.)--Auburn University, 2005. Abstract. Includes bibliographical references (leaves 8... more Thesis (Ph. D.)--Auburn University, 2005. Abstract. Includes bibliographical references (leaves 82-87).
International Journal on Pavemnet Engineering & Asphalt Technology, 2013
Micro-Surfacing is a polymer modified, binder emulsion based, dense graded, cold mixed, and quick... more Micro-Surfacing is a polymer modified, binder emulsion based, dense graded, cold mixed, and quick setting, asphalt resurfacing material. Type III application of microsurfacing is used as the rut fill materials for highly trafficked roads. As of now, International Slurry Surfacing Association (ISSA) mix design guideline is the widely used standard to design micro-surfacing mixtures. The research described in this paper intended to suggest modifications to the actual ISSA mix design procedure to accurately select aggregate grading for type III micro-surfacing mixtures. To do this, a sensitivity analysis was performed in order to study the effect of aggregate gradation, and binder emulsion residue on five micro-surfacing mixture design tests, including Loaded wheel test (ISSA TB 109), Wet track abrasion test (ISSA TB 100), modified cohesion test (ISSA TB 139), vertical displacement test (ISS TB 109, Method-A), and Mixing time test (ISSA TB 113). The second part of study consisted mainly of establishing a limit for the aggregate gradation used in type III application of micro-surfacing, which gives higher resistance to rutting as it is the main property of type III micro-surfacing. In order to do this, the resistant of different micro-surfacing mixtures against rutting was evaluated, and modified specifications were suggested to select aggregate grading for type III microsurfacing.
Bituminous Mixtures and Pavements VI, 2015
The increase in the use of Reclaimed Asphalt Pavement (RAP) makes it necessary to focus on the in... more The increase in the use of Reclaimed Asphalt Pavement (RAP) makes it necessary to focus on the interaction between the old and the virgin binders represented by the so-called blending chart. Different types of linear binder blending chart are currently available to predict the characteristics of the final blend. This study constitutes part of a wider research campaign whose aim it is to provide prediction models for the rheological properties of RAP, taking into account a selection of variables that cause its heterogeneity. The objective of this paper is to provide a multiple regression model at medium and high temperatures for the prediction of the complex modulus and phase angle of binder blends. The models consider more than one variable at the same time: the type of virgin and aged binders, the percentage of aged binder, the loading frequency and the temperature. Thus, within a specific validity range based on the extreme values defined by the experimental domain, it is possible to predict the rheological properties of the binder blends, and to carry out a sensitivity analysis on the effects of each parameter.
Canadian Journal of Civil Engineering, 2015
Although Micro-surfacing is widely used, current tests and mix design methods mostly rely on labo... more Although Micro-surfacing is widely used, current tests and mix design methods mostly rely on laboratory condition and the correlation between laboratory results and field performance is poor. Therefore, there is a need to develop new mix design procedures, specifications, and guidelines for Micro-surfacing. The research described in this thesis intended to review the current mix design procedures for Slurry Seal and Micro-surfacing and suggest modifications to the actual International Slurry Seal Association (ISSA) mix design procedure for microsurfacing as a high performance surface treatment and pavement preservation method. The first part of study reports the findings of a detailed laboratory investigation concerning the effect of asphalt emulsion, added water content, and the use of additives (Portland cement) on the design parameters and properties of micro-surfacing mixtures. For this, one aggregate type, one asphalt emulsion type/grade, and one aggregate gradation were used in the study. The evaluation was conducted at one curing stages of the mix (24-Hours). Three levels of asphalt emulsion, four levels of added water content, and one level of Portland cement were used in order to evaluate role of asphalt emulsion, water, and cement. This part of study consisted mainly of establishing a method for preparing and testing micro-surfacing mixture using four main mixture design tests proposed by the ISSA (TB 139, TB 113, TB 100, and TB 109). The results obtained with ISSA TB 109 and ISSA TB 100 mixture design tests were found highly variable and not precise enough to suggest optimum mix design. For the second part of this study, different tests were also studied in order to refine the current mix design procedure. The results have shown that ISSA TB 139 can be used to define the optimum water content at which samples should be tested, and that ISSA TB 147 mix design test should be used to define the optimum asphalt emulsion content.
Transportation Research Record, 2005
Ride quality assessed with an inertial profiler on flexible pavement was used to provide initial ... more Ride quality assessed with an inertial profiler on flexible pavement was used to provide initial information on the following key issues: repeata-bility associated with international roughness index (IRI) values for a wide range of hot-mix asphalt (HMA) material variables, timing of ...
Materials and Structures, 2014
Journal of Transportation Engineering, 2007
ABSTRACT Statistical analyses of over 2,000 pavement designs using the 1993 American Association ... more ABSTRACT Statistical analyses of over 2,000 pavement designs using the 1993 American Association of State Highway Transportation Officials Design Guide was conducted. Variations in traffic levels, and subgrade, base, and hot mix asphalt (HMA) moduli and thickness showed that the only significant material and traffic design inputs were the subgrade modulus and the initial ESAL loads. A plus or minus 5% change in the design traffic level did not statistically influence the determination of the structural number (SN). A subgrade modulus of 3,000 psi and a linear growth rate of 4% for roadways with annual average daily traffic of more than 10,000 is recommended for determining the SN. The growth rate for lower traffic volume roadways will vary significantly between 0 and 3%. A more limited evaluation of the 2002 Design Guide showed that a mechanistic-empirical method of flexible pavement design is strongly influenced by the HMA thickness and the distribution of truck types within the annual average daily traffic. Selecting the appropriate roadway functional classification defines the default percent of traffic that is comprised of trucks and is important to the program output. Performance data for two Alabama long-term pavement performance sections was used to verify both design methods.
Canadian Journal of Civil Engineering, 2002
In an attempt to apply the concepts developed by Carman and Klinkenberg for the measurement of pe... more In an attempt to apply the concepts developed by Carman and Klinkenberg for the measurement of permeability of a porous media using a gas, a permeameter for the in-situ measurement of intrinsic permeability of skin concrete has been developed. The established technique allows concentration of gas percolation through a well-defined zone in the superficial layer of concrete. The instrument, the measurement method, and the calculation procedure are described in details in this paper. Several series of tests have been performed in laboratory on concrete blocks (300 × 300 × 400 mm) to simulate measurements on the construction site. Three types of concrete, with different porosity, have been tested. The measurement of permeability performed on the concrete blocks have been accomplished both on shaped surfaces, which are representative of skin concrete, and on sawed surfaces, which are representative of mass concrete. Results show that the relationship between the water/cement ratio and th...
Australian Journal of Civil Engineering, 2013
ABSTRACT The first part of this study evaluates the repeatability of the International Slurry Sur... more ABSTRACT The first part of this study evaluates the repeatability of the International Slurry Surfacing Association (ISSA) mixture design tests. Consistency of test results between two laboratories (MTQ and LCMB) and within material combinations was evaluated. Aggregate gradation and sample preparation method were varied, and the responses for various ISSA mix design test for micro-surfacing were examined. The repeatability of four ISSA mix design tests for micro-surfacing was computed. To do this, the micro-surfacing mixtures were prepared by four technicians at two laboratories in Quebec. Modified cohesion test, wet track abrasion test, loaded wheel test, and resistance to compaction test were those evaluated in this study. The effect of sample preparation method using aggregate splitting and sieve analysis on consistency of mixture design test results was also evaluated in this part of study. It was observed that employing sieve analysis method for micro-surfacing mixture preparation yields the more consistence test responses. For the second part of this study, the role of aggregate gradation, and their total surface area on cohesion, resistance to abrasion, and resistance to permanent deformation of micro-surfacing mixtures was studied. Two different type III applications of micro-surfacing mixtures which are used as rut-fill materials in highly traffic area were selected to determine the effects of aggregate total surface area on micro-surfacing mix design test responses. It was found that the micro-surfacing mixtures prepared using aggregate gradation with more fine aggregates have higher resistance to rutting, bleeding, abrasion, moisture susceptibility, and early rolling traffic.
Colored asphalt materials are gaining more attention in the European market due to their architec... more Colored asphalt materials are gaining more attention in the European market due to their architectural/aesthetic prospective and their effect as a signal on the road. Especially in Netherlands this technology has gained popularity and is currently used for red bicycle lanes for example. Micro-surfacing mixture, as a pavement preservation and surface treatment method, is typically made with bitumen base mixes predominantly composed of virgin aggregates, and quick setting polymer modified bitumen emulsions. In order to study the feasibility of formulating colored micro-surfacing mixtures with increased durability, research was conducted at Latexfalt B.V. in The Netherlands in collaboration with Laboratoire sur les Chaussées et Matériaux Bitumineux (LCMB), at École de technologie supérieure (ÉTS) in Canada. The first part of the study examined the possibility of producing coloured micro-surfacing mixtures by using clear binder modified with different types of polymer. The goal was to c...