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Asphalt stripping is a common form of distress caused by moisture that creates a loss of bond between the aggregate and binder. It is thought that the use of warm mix asphalt (WMA) technology could lead to increased moisture susceptibility if the free moisture present in the aggregates does not evaporate at the lower mixing temperatures. The purpose of this study is to evaluate the moisture susceptibility of WMA using Evotherm 3G on laboratory-prepared and plant-prepared mixes. The moisture damage potential was evaluated using the TSR (tensile strength ratio), the static immersion test, moisture-induced stress tester, and Hamburg wheel tracking test. Additionally, plant-prepared mixes were also assessed for TSR and rut depth. The results indicated that WMA provided adequate levels of resistance to moisture damage, reduced swelling, and improved coating. Laboratory mixes showed reduced resistance to rutting, but rut depth of plant mixes was similar to that of hot mix asphalt. Key words: hot mix asphalt, warm mix asphalt, Evotherm 3G, moisture susceptibility Le desenrobage de l'asphalte est une forme courante de degradation causee par l'humidite qui cree une perte de liaison entre le granulat et le liant. On pense que l'utilisation de la technologie de l'asphalte melange tiede (AMT) pourrait accro'tre la vulnerabilite a l'humidite si l'humidite libre presente dans les agregats ne s'evapore pas aux temperatures plus basses de malaxage. Le but de cette etude est d'evaluer la sensibilite a l'humidite de l'AMT a l'aide d'Evotherm 3G sur des melanges prepares en laboratoire et prepares en usine. Le potentiel de dommages causes par l'humidite a ete evalue a l'aide du RRT (rapport de resistance a la traction), l'essai d'immersion statique MiST (testeur de resistance induite par l'humidite) et HWTT ([much less than] Hamburg wheel tacking tester [much greater than]). En outre, les melanges prepares a l'usine ont egalement ete evalues pour le RRT et la profondeur des ornieres. Les resultats ont indique que l'AMT offrait une resistance adequate aux dommages causes par l'humidite, reduisait le gonflement et ameliorait le revetement. Les melanges de laboratoire ont montre une resistance reduite a l'ornierage, mais la profondeur des ornieres des melanges d'usine etait semblable a celle de l'asphalte melange a chaud. [Traduit par la Redaction] Mots-cles : asphalte melange a chaud, asphalte melange tiede, Evotherm 3G, sensibilite a l'humidite, 1. Introduction Warm mix asphalt (WMA) additives reduce the viscosity of the asphalt binder, thus lowering the temperature required for sufficient coating of all aggregate particles and compaction in the [...]

In North America, highway agencies have started using Superpave as it incorporates a performance-based asphalt binder specification and a mix design analysis system. However, in a pavement management system (PMS), the performance of the pavement structure significantly influences management decisions. In this regard, accurate prediction and evaluation of performance is a very important aspect. With this in mind, this study investigates the performance of Superpave through the mechanistic-empirical (M-E) approach, field-evaluated performance, and laboratory performance tests. It considers 15 sections of highways from Ontario. The investigation found that the international roughness index (IRI) and permanent deformation are overpredicted in the M-E approach compared with field observations. Additionally, to better understand the performance, the dynamic modulus of asphalt mixtures and binder rheological testing are also performed. The master curve developed for the surface mixtures suggests a lower level of fatigue resistance that justifies the bottom-up fatigue failure in the field-observed scenarios. Key words: Superpave, mechanistic-empirical (M-E) approach, mechanistic-empirical pavement design guide (MEPDG), pavement condition evaluation, pavement performance, dynamic modulus test. En Amerique du Nord, les organismes responsables de voirie ont commence a utiliser Superpave, car ce systeme integre une specification de liant d'asphalte basee sur le rendement et un systeme d'analyse de la conception du melange. Toutefois, dans un systeme de gestion routiere (SGR), le rendement de la structure des chaussees a une incidence considerable sur les decisions de gestion. A cet egard, l'exactitude des previsions et de l'evaluation du rendement sont des aspects tres importants. Dans cette optique, la presente etude se penche sur le rendement de Superpave au moyen de l'approche mecanisteempirique (M-E), evalue le rendement sur le terrain et effectue des essais de rendement en laboratoire. On considere 15 troncons d'autoroute du reseau routier de l'Ontario. Il ressort de cet examen que l'indice de rugosite international (IRI) et la deformation permanente sont surestimes dans l'approche M-E par rapport aux observations sur le terrain. De plus, afin de mieux comprendre le rendement, un module dynamique des melanges d'asphalte et des essais rheologiques de liant sont egalement effectues. La courbe maitresse developpee pour les melanges de revetement suggere un niveau inferieur de resistance a la fatigue qui justifie la rupture par fatigue ascendante dans les scenarios observes sur le terrain. [Traduit par la Redaction] Mots-cles : Superpave, approche mecaniste-empirique (M-E), guide de conception mecanisto-empirique des chaussees (<< mechanistic-empirical pavement design guide (MEPDG) >>), evaluation de l'etat de la chaussee, tenue de la chaussee, essai du module dynamique., 1. Introduction In North America, highway agencies began using the Superior Performing Asphalt Pavements (Superpave) system in the 1990s with consideration of improved performance. Superpave is a comprehensive asphalt mix [...]

Coloured pavements have been implemented by metropolitan areas to denote dedicated lanes for bus rapid transit to maintain a high level of safety. Transit benefits of these installations are well documented. However, field performance of various types of coloured pavement has not been investigated systematically, with questions not being answered. In collaboration with the Regional Municipality of York (ON, Canada) where red pavement sections have been in operation for years for its bus rapid transit lanes, the Centre for Pavement and Transportation Technology at the University of Waterloo (Waterloo, ON, Canada) assessed the performance of various types of red pavements including epoxy paint and red asphalt mixes. It was found that, with significant lower texture depth, epoxy paint surface has disadvantages to red asphalt pavement from a pavement texture and safety perspective. The red asphalt sections in this study were observed as lower yet compatible frictional levels to conventional black pavement. Various types of contamination onto the red pavement were observed during field survey. In addition, the ultraviolet radiation degraded the colour of red asphalt pavement over time and may make it less effective for lane designation. Long-term monitoring is recommended to evaluate the functional and structural performance of red asphalt pavement. [ABSTRACT FROM AUTHOR]