Michel Vaillancourt

Evaluation of the impact of recycled glass on asphalt mixture performances

The goal of this research was to verify the possibility of using recycled glass particles in an asphalt mixture while maintaining equivalent properties and performance in lieu of a conventional mixture. First, one type of asphalt mixture (ESG14) with different glass contents was tested according to the Ministère des transports du Québec’s mix design method. Next, the performances (resistance to thermal cracking, mixture stiffness and stripping resistance) of an asphalt mixture with optimal glass content were evaluated and compared to a reference mixture. Overall, it was found that using recycled glass in an ESG14 asphalt mixture reduces the binder content, increases the mixture workability and decreases the rutting resistance. It was also found that using 10% recycled glass in an ESG14 asphalt mixture does not impact the resistance to thermal cracking as well as the mixture stiffness. On the other hand, the stripping resistance is negatively affected by the presence of glass.

Laboratory evaluation of complex modulus and fatigue resistance of asphalt mixtures with RAP

The evaluation of the performance of recycled asphalt mixtures is a priority for the asphalt materials community. The results of the investigation dealing with the linear viscoelastic properties and fatigue resistance on RAP mixtures are presented. Complex modulus and fatigue properties of recycled asphalt mixtures are investigated on tension–compression tests (T-C). Four asphalt mixtures including four RAP contents (0, 15, 25, 40 %), one virgin aggregate, and one asphalt binder (PG 64-28) were investigated in this study. In general, the results of this study indicate that: 1) the asphalt mixtures containing RAP have higher or similar stiffness with the control mixture containing no RAP, 2) the asphalt mixtures containing 25 % RAP have the highest stiffness at lower temperatures or high frequencies, and 3) no general trend was found between the amount of RAP and the number of cycles to reach fatigue failure. In addition, high fatigue resistance was observed in mixtures containing 40 % RAP.

Linear viscoelastic (LVE) properties of asphalt mixtures with different glass aggregates and hydrated lime content

ABSTRACT In this paper, the results of a research project examining the effect of glass aggregate and hydrated lime content on linear viscoelastic (LVE) properties are presented. Three glass aggregate contents (0%, 20% and 60%) and two hydrated lime contents (0%, 2%) were studied for a total of six different asphalt mixtures. All mixtures were fabricated in the laboratory using a PG70-28 polymer-modified binder. LVE properties were measured with the complex modulus (E*) test (tension compression on cylindrical specimens) at different temperatures (−35°C to +35°C) and frequencies (0.01 Hz to 10 Hz). Experimental E* test results were modelled with the 2S2P1D model. The Partial Time-Temperature Superposition Principle (PTTSP) was applied with good precision. Differences in terms of LVE properties were found for mixtures with glass aggregate compared with conventional mixtures. The glassy modulus, as well as the complex modulus norm, was decreased due to the glass aggregates. Moreover, the normalisation of the E* results showed that adding 60% glass changes the LVE properties. No notable effect related to the hydrated lime content was observed.

Thermal Properties of Base-Course Material Containing Recycled Glass Under Dry and Wet Condition

The increasing need to recycle waste and reduce the use of landfills has led to the reconsideration of the use of recycled glass aggregates in pavement construction. While the mechanical and hydraulic performances of recycled glass aggregates (RGA) in roadwork applications are well documented, their thermal performance is almost unexplored. However, in cold regions, the adequate thermal design of pavement relies on a good prediction of the thermal regime in the road structure. Glass is known for its insulating or heat-retention properties (low thermal conductivity). Aggregates and aggregate mixtures with low thermal conductivity can help decrease the depth of frost penetration. This experimental study aimed to evaluate the thermal properties of RGA blended with natural aggregate (NA). In this paper, we present the results of thermal conductivity and thermal diffusivity measurements on RGA, NA and NA blended with RGA (NA/RGA). Our methodology included the influence of particle size, moisture content and glass content. At a given moisture content, the thermal conductivity of RGA and NA decreased with increasing particle size. The results show that an increase of water content in any of the studied material increased its thermal conductivity but at relatively different rates. It was also found that increasing the percentage of glass in NA/RGA blends decreased their thermal conductivity.