Alan Carter

• Professor
• École de Technologie Supérieure

There is compelling evidence supporting the benefits of incorporating crumb rubber to enhance the properties of bituminous mixes. The main aim of this paper is to investigate the effect of crumb rubber on the rheological properties of bituminous mixes using the dry method. A comparison was made in terms of linear viscoelastic behaviour, between fiv...

Higher reclaimed asphalt pavement (RAP) in asphalt mixtures requires efficient rejuvenation. The efficiency of the rejuvenation can be evaluated by studying the rejuvenator, new and old binder blend. The blend must represent the binder blend inside the asphalt mixture to reflect reality. Extracting and recovering the binder of the rejuvenated aspha...

Waste glass accounts for huge quantities throughout the world. Although some part of this waste material is recycled, a considerable part of waste glass cannot be reused and recycled due to the glass remanufacturing strict limitations. Hence, reusing waste glass in construction projects can be a cost-effective and environmentally friendly method to...

This study investigated the use of recycled glass aggregate (RG) as unbound base/subbase material. The experimental tests included compaction, Los Angeles, Micro-Deval, and California bearing ratio (CBR) tests. In this regard, a fine proportion of course limestone aggregate (MG20) was replaced by RG with size ranging from 0 to 5 mm based on the vol...

The primary aim of this study is to correlate the impact of aggregates, if any, on the viscoelastic behavior of rejuvenated asphalt mixtures containing very high amounts of reclaimed asphalt pavement (RAP) (> 50%). First, gradation of 100% RAP was rectified, using a modified Bailey method by adding virgin aggregates to achieve two coarse dense-grad...

Efficient rejuvenation of the RAP’s binder facilitates the use of higher RAP contents. Assessing the efficiency requires evaluating the right blend of the rejuvenator, new and old binder that represents the real binder blend inside the asphalt mixture. Extracted and recovered (E&R) binder from the rejuvenated asphalt mixtures containing RAP is the...

As part of the RILEM Technical Committee TC 279-WMR on valorisation of waste and secondary materials for roads, Task Group 3 used various waste aggregates as a replacement for natural aggregates in asphalt mixtures, namely, construction and demolition waste, recycled concrete aggregates and steel slag. For this interlaboratory exchange program, the...

RILEM TC-279 WMR task group TG 1 studied the performance of waste Polyethylene (PE) in bituminous binders and bituminous mixtures. Several laboratories participated in this study following a common protocol. Locally sources aggregates and bituminous binder and same source of waste PE were utilized. The binder experiments showed that at high tempera...

Environmental approaches in the asphalt industry have focused on utilizing waste materials as modifiers. Lignin is a high-potential bitumen modifier due to its characteristics; however, the blending process with bitumen is critical. This study investigates the chemo-thermal characteristics of lignin-modified bitumen under two different blending pro...

Construction and demolition waste (CDW) materials account for a considerable part of waste materials throughout the world. As these materials are not usually recycled, reusing them in construction projects is of major significance. In this study, recycled concrete, bricks, and glass were used as 100% aggregates of chip seal, which is a corrective o...

Using interlayers made of geosynthetic materials has proved its effectiveness with respect to postponing the appearance of reflective cracking on the surface. In this regard, in a reinforced bituminous interface, the crack first propagates from its origin upward until it reaches the interlayer. When the interlayer has higher stiffness than its surr...

Road pavement generates significant environmental impacts through the production, transportation , construction, and maintenance stages. Recycling methods can be used to reduce the demand for virgin materials, but these alternatives are not environmentally benign either. Using life cycle assessment of a real case study near Chatham, Ontario, we mod...

This work aims to characterize the rheological properties of lignin-modified bitumen. Various contents (0, 10, 20 and 30% by total mass of the modified bitumen) of Kraft lignin, which is derived from softwood and were used with two soft and unmodified bitumen adapted for cold climates and standard traffic level (PG 58S-28 and PG 52S-34). Storage st...

Bailey method is a well-proved method to build strong aggregate structure, but it is originally devised to do so by proportioning the fractionated virgin aggregate stockpiles. Yet, the concepts of strong aggregate structure in the Bailey method stand true in any type of aggregate. This study develops a method for correcting the bad gradation of RAP...

The objective of this research is to study the impact of the use of construction, renovation and demolition (CRD) fillers on the linear viscoelastic behavior (LVE) of bituminous mastics. Forty-two (42) mastics, composed of a PG 64H-28 bitumen and 4 different contents of various types of filler, were created: concrete (Co), hydrated lime (HL), glass...

This study examined the effects of the laboratory mixer type and mixing time on a hot-mix asphalt (HMA) using three different types of mixers and four different mixing times. The asphalt mix used is a semi-open graded mix (ESG-10) with 30% reclaimed asphalt pavement (RAP), and a range of tests were conducted including bitumen extraction by ignition...

Rutting, fatigue and thermal cracking are the most prominent pavement degradation observed in Canada. The presence of cracks on the surface allows water to seep into the pavement structure and accelerate its degradation. One of the options to remove cracks is to mill a thin layer and replace it with a new layer. Unfortunately, reflective cracking r...

Heat transfer in the asphalt pavement is significant because it affects asphalt pavement performance and the surrounding environment. This importance is attributed to summertime when the pavement's surface is hot. This hot surface can cause asphalt pavement distresses such as rutting and exacerbate cities' urban heat islands (UHI). Therefore, under...

Conventional mix design methods are incapable of making the most of RAP, especially in very high content (>50 %). RAP is not the kind of waste to just get rid of, but it has the potential to build better asphalt pavements. Therefore, the aim of this research is to modify practices and criteria within mix design and develop a ranking system in order...

The use of cold recycled asphalt mixtures (CRM) has been soaring during recent years. Reclaimed Asphalt Pavement (RAP) is the main component of CRM, and despite the numerous studies on CRM, the impact of different RAP types has not been deeply studied. This study compares the volumetric and several mechanical properties of CRM prepared with RAP fro...

Cold recycling of asphalt mixes is becoming a usual pavement rehabilitation technique. The use of active fillers in conjunction with bituminous emulsion changes the properties of the mixes, mainly on the mastic characteristics. The use of active filler can make the mastic more brittle, but limited data are available on this aspect. In this study, e...

The use of Reclaimed Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) in asphalt mixes is a constructive solution allowing economic, environmental and technical benefits. The objective here is evaluating the binder mobilisation rate of recycled materials by predicting the viscoelastic (LVE) behaviour of the asphalts from the LVE of their...

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 an...

The use of waste materials such as rubber powder in stone mastic asphalt (SMA) has improved the structural performance to some extent, and the research on the improvement is still ongoing. Rubberised stone mastic asphalt has shown good performance in terms of resilient modulus. In this research, response surface methodology was utilised to increase...

This recommendation is based on the results of an inter-laboratory study organised by the RILEM technical committee TC 264-RAP "Asphalt Pavement Recycling"—Task Group 3 (TG3) focusing on Asphalt Binder for Recycled Asphalt Mixture. The TG3 aimed to evaluate the effect of a specific family of materials known as asphalt recycling agent (ARA) on the a...

The use of rejuvenators has seen a consistent increase over the years in the asphalt pavement industry. This is due to the need for maximizing the demand for incorporating a higher amount of Reclaimed Asphalt (RA) in the pavement asphalt mixtures. In order to tackle this challenge, the Task Group 3, focusing on asphalt binders and additives, of the...

Cold recycling of reclaimed asphalt (RA) is a promising technique to build or to maintain roads, combining performance and environmental advantages. Although this technique has been extensively used worldwide, there is no unique and internationally-shared method to characterize cold recycled mixtures. The previous work of the RILEM TC 237-SIB TG6 s...

High modulus asphalt concretes (HMACs), enrobés à module élevé (EMEs) in French, improve asphalt pavement durability due to their high rigidity, high resistance to rutting and fatigue and in some cases very good low-temperature behaviour. The goal of the current study is to perform a sensitivity analysis of HMAC (EME) developed specifically for col...

The use of Reclaimed Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) in combination with new materials in asphalt mixes appears to be a good solution to achieve economic and environmental benefits while maintaining or increasing the performances. The main objective of this work is to verify the application of the two blending laws for th...

The Task Group 2 of the RILEM Technical Committee 264-RAP on non-cold recycling identified the need to gather some insights about possible durability issues associated with the combination of Warm Mix Asphalt (WMA) and of Reclaimed Asphalt (RA) in order to prioritize the characterization or research needs for relevant damage types. For this purpose...

Impregnated geotextiles are commonly used in road construction or rehabilitation to minimize water infiltration into the pavement structure. However, the effects of such waterproofing membranes on the mechanical behavior of the pavement structure are difficult to predict. In this paper, Falling Weight Deflectometer (FWD) measurements were used to h...

Inter-laboratory experiments were designed to evaluate the impact of plastic waste blended directly in bitumen and to assess the properties, using conventional and advanced bituminous binder testing. The blends targeted 5% of plastic waste in 95% bitumen, using two types of polyethylene (PE) primary (pellets) and secondary (shreds) waste. The exper...

In this paper, the effects of pre-cracking on the early-age mechanical properties of a cement-treated base material (CTBM) were studied. To do so, CTBM with 4% cement by mass of dry granular material were mixed in laboratory in order to make cylindrical specimens. Half of the specimens were pre-cracked (PC) with a mechanical impact hammer after a t...

Cold recycled materials (CRM) have been introduced as structural materials in road pavement structures thanks to their significant economical and environmental benefits. Among them, cement-bitumen treated materials (CBTM) are often employed because of both contributions given by bitumen (in form of emulsion) and cement. The first confers a bitumino...

The fatigue's behaviour of bituminous materials is affected by the loading frequency. For hot mix asphalt (HMA) with unmodified bitumen, previous research showed a decrease in fatigue life, under strain-control mode, by increasing loading frequency. However, the effect of loading frequency on polymer-modified HMA has not been investigated extensive...

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...

Rutting, fatigue and thermal cracking are the most prominent pavement degradation observed in Canada. The presence of cracks on the surface allows water to seep into the pavement structure and accelerate its degradation. One of the options to remove cracks is to mill a thin layer and replace it with a new layer. Unfortunately, reflective cracking r...

The application of paving fabric (a system composed of a layer of geotextile along with asphalt cement) between an existing deteriorated bituminous layer and a fresh asphalt overlay, as a newly developed rehabilitation strategy, has proved its effectiveness in terms of delaying the propagation of reflective cracks. Nevertheless, this application re...

In view of increasing social and environmental consciousness, a circular approach in waste materials management in order to convert them into new secondary resources is becoming more necessary. Given this context, an interlaboratory testing program (ILTP) focusing on maximizing the use of waste aggregates replacing conventional virgin ones has been...

Use of additives and modifiers as an effective alternative to mitigate premature cracking of flexible pavements has been gaining popularity during the past three decades. Several studies have discussed the advantages and disadvantages of using various types of fibers in pavement industry. The objective of this study is to evaluate the impact of usi...

A correction to this paper has been published: https://doi.org/10.1617/s11527-021-01656-3

The installation of a layer of grid, as an interlayer between bituminous layers, enhances the mechanical performance of the entire system under repetitive action of traffic loads, typically by increasing the tensile and shear strength at the interface level. At the same time, this mechanical improvement is accompanied by changes in mechanical respo...

In the framework of recycling techniques employed in maintenance and rehabilitation projects for the road industry, cement bitumen-treated materials (CBTMs) provide good performance as well as economic and environmental benefits. Because these materials are produced with bitumen emulsion at atmospheric temperature, the environmental factors during...

Cold recycled materials (CRMs) are products of modern recycling techniques that are used in maintenance and rehabilitation of pavement structures with significant economical and environmental benefits. CRM mixes are produced at ambient temperature using bitumen emulsion or foamed bitumen as a binding agent, and the aggregate phase is composed mainl...

In this study, the mechanical properties of composite bituminous structures with geogrid products, used as an interlayer between different types of bituminous mixtures, at a constant temperature, were examined. A twofold experimental program based on new approaches was selected. A new configuration of the 3-Point Bending Test (3-PBT) was adopted to...

The use of Reclaimed Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) in combination with new materials in asphalt mixes appears to be a good solution to achieve economic and environmental benefits while maintaining or increasing the performances. The main objective of this work is to verify the application of the two blending laws for th...

Bituminous pavements frequently fail at an early age well below the predicted design life, which in turn necessitate taking rehabilitation actions to recover the serviceability to an acceptable level for the users. Two rehabilitation techniques have been the focus of the engineering community: a traditional method known as the mill and fill and the...

The mechanical evaluation in the laboratory of the impact of the reinforcement of bituminous layers deteriorated by a geosynthetic layer, in order to obtain rational inputs in the methods of dimensioning of the pavements based on the performance, represents a real challenge. This complexity has two main origins. On the one hand, the preparation of...

Bituminous pavements cover a large part of Canada’s roadway network. Traffic and environmental loadings cause distresses and damages in the pavement structure. A traditional approach for pavement rehabilitation is to implement an asphalt overlay on existing deteriorated bituminous pavement at specific times during its service life. However, this ap...

Nowadays, one of the main challenges to a wider application of cold recycling techniques is the lack of reliable information on the mechanical behavior of cold recycled materials (CRM). In this context, measurement and modelling of the complex modulus of CRM mixtures may give an important contribution to the design and analysis of pavements includi...

Road pavements placed in cold regions are subjected to harsh changes of temperatures both seasonally and daily which in turn influences the stiffness behavior of asphalt mixes through freeze-thaw cycling. This effect plays an important role on the performance of asphalt pavements, which is not taking into consideration in current methods of pavemen...

The growing use of reclaimed asphalt (RAP) results in a continuous increase in the percentage of added RAP to hot mix asphalt. Within the asphalt pavement, the asphalt binder is the component which is affected the most by the ageing during service life, resulting in considerable hardening of the RAP binder. Therefore, the aged binder needs to be re...

The use of reclaimed asphalt (RA) in road pavements is continuously gaining interest thanks to the technical, economic and environmental advantages guaranteed by such sustainable practice. Cold recycling techniques compared to traditional asphalt mixes allow a significant reduction of energy, fume emissions, use of natural resources, etc. In this p...

Cold recycled materials are mixes with high percentages of reclaimed asphalt (RA), while the binding phase is commonly composed of Portland cement and bitumen (emulsion or foam). The reproduction of such materials in the laboratory is an important issue for an accurate mix design, even more when applying a volumetric approach. Particularly, the lac...

This research aims to evaluate the performance of the hot mix asphalt modified with crumb rubber by the dry process by studying the temperature’s influence as well as the impact of the digestion time between bitumen and crumb-rubber. The residual bitumen from the drainage test and the non-modified aged bitumen are then subjected to the dynamic shea...

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...

In order to study the mechanical behavior of asphalt overlay reinforced with paving fabrics (a system composed of non-woven geotextile and asphalt cement) a new methodology was developed based on three new pieces of laboratory equipment including 3-point bending test (3-PBT) method on cylindrical specimens, crack widening device (CWD) and water-vac...

The focus of this study is on thermally induced reflective cracking, which has been recognized as a prevalent issue in North America. It first initiates by excessive tensile stress from expansion, contraction or bending from horizontal movement of the layers due to significant drop or high daily fluctuation in temperature (Mode I). Then, the crack...

Absorption ability of aggregates is one of the most important material characteristics in the perspective of a bituminous mixture mix design. In particular, this aspect gains more importance in the framework of cold recycled mixtures (CRM). Since such materials are produced at ambient temperature, the workability is ensured by the employment of bit...

Cold recycled mixtures (CRM) treated with bitumen emulsion are innovative materials in road pavement construction industry which gained visibility in the last decades. They are produced at ambient temperatures thanks to the employment of bitumen emulsion, water and additional hydraulic binders. In this research, four CRM mixes are studied analysing...

Several studies show that properties of Hot Mixture Asphalt (HMA) mix design materials, aggregate gradation and volumetric properties had an influence on their resistance to rutting. However, these properties do not impact in the same way this performance. For a given aggregate type, an infinity aggregate gradation type can be observed, and for eac...

Abstract The most famous model known in prediction of dynamic modulus for asphalt concretes is the Witczak and Hirsh models. These models didn’t use the mineralogical and chemical properties of aggregates. Witczak models used the passing or refusal percentage to sieve diameters and Hirsh model used the volumetric analysis. All models developed unti...

Pavement design tools are not universal. Indeed, in the sizing of pavements in the USA, the prediction models used in the calculation of the dynamic modulus of HMA are not adapted to the characterization of the mineral skeleton of the HMA mix designed with the French method. This article aims to assess the predictive models of the dynamic modulus u...

Low volume road rehabilitation is an important part of pavement projects done in Canada. Unfortunately, the municipalities have very limited budget for pavement maintenance and rehabilitation. One option to rehabilitate low volume rural roads is to use flexible asphalt mixes. Those mixes can resist rutting and thermal cracking, but they are flexibl...

Cold bitumen emulsions (CBE) are currently used worldwide for both non-structural (cold surface treatments) and structural (cold bituminous mixtures) paving applications. Among non-structural applications, bituminous slurry surfacings (BSS) allow to improve surface properties and extend the pavement’s life. However, selection of constituents, mix d...

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 effe...

In cold regions, the production of Cement-Bitumen Treated Materials (CBTM) represents an issue in terms of annual time available for production. The objective of this research is to study the influence of different combinations of production temperatures for mixing, compacting and curing (developed in two steps) on the mechanical properties of CBTM...

The use of alternative materials in the construction industry is gaining popularity, amongst other to reduce the various environmental impacts of standard construction materials. Recycled glass (RG) is used as an aggregate in pavement structures, but the widespread usage is impeded by insufficient knowledge on the geotechnical characteristics. This...

Full-depth reclamation (FDR) materials are a type of cold-recycled bituminous mixes that are composed of reclaimed asphalt pavement (RAP) and virgin aggregates. FDR is often treated with a binder in order to obtain cohesion. It is common to use bitumen emulsion, foam asphalt, and cement. In many parts of the world, when bitumen emulsion or foamed a...

In recent times, recycling using cold bituminous mixtures has become one of the most interesting techniques in pavement engineering from sustainability aspect. This study focuses on the clarification of the steps concerned with the cold mixture mix design to determine the initial aggregate gradation of the mixture. The study has been developed invo...

In most countries, there is a low temperature limit to lay down hot asphalt mixes because if it is too cold, it becomes impossible to get proper compaction. For cold recycled bituminous mixture (CRM), there is little information on the effect of the low temperature on their behavior. The goal of this study is to evaluate, in laboratory, the impact...

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 resist...

https://www.tandfonline.com/eprint/KD3Pt8fAiJH8Zx33uZ7w/full?target=10.1080/14680629.2019.1588775 (50 free eprints available) Cold Recycled Mixtures (CRM) are composed of high amounts of Reclaimed Asphalt Pavement (RAP) together with bitumen emulsion. As additional binder, some ordinary cement is normally employed. Since RAP aggregates represents a...

Cold recycled bituminous materials can consist of up to 100% reclaimed asphalt pavement (RAP) treated with different binders such as bituminous emulsion and foamed bitumen, as for Hot recycling the highest percentage is trying to be achieved, recent studies suggest 40% as a possible percentage of RAP in hot asphalt mixtures, actually some countries...

The characterization of cold recycled pavement materials at an early stage of their life, right after compaction, is difficult especially if classical tests are used. Indeed, these materials at very young age behave like granular materials, which affect the feasibility of the usual tests done on bituminous materials. Non-destructive techniques usin...