Mechanical performance assessment of half warm recycled asphalt mixes containing up to 100 % RAP

Abstract

ABSTRACT:The use of Half Warm Mixes with high Reclaimed Asphalt content (HWMRA) has the potential to generate significant environmental advantages such as the reduction in consumption of natural resources and the emission of gases into the atmosphere. This paper therefore focuses on demonstrating the viability of using these types of mixes in wearing courses. For this purpose, an HWMRA with 70 % and 100 % Reclaimed Asphalt Pavement (RAP) and emulsion were designed in the laboratory. The performance of the mixes was then assessed and compared with that of conventional Hot Mix Asphalt. In a second stage, the mixes were manufactured in-plant, and laid and compacted in an Accelerated Pavement Test track. The cores were then extracted and tested for stiffness modulus and resistance to fatigue. The results from the tests conducted with both the laboratory specimens and the cores showed that the performance of HWMRA is comparable to that of HMA. These findings encourage greater confidence in promoting the use of these types of sustainable asphalt mixes. RESUMEN:Evaluación del comportamiento mecánico de mezclas asfálticas templadas con 100 % de material reciclado. La utilización de mezclas asfálticas templadas con alto contenido de asfalto reciclado (HWMRA) conlleva ventajas medioambientales como la reducción del consumo de recursos naturales y la emisión de gases a la atmósfera. Este artículo se centra en mostrar la viabilidad de este tipo de mezclas para capas de rodadura. Para ello, se diseñaron mezclas HWMRA con 70 % y 100 % de asfalto reciclado en el laboratorio y se evaluó y comparó su comportamiento con una mezcla caliente convencional. En una segunda etapa, las mezclas fueron fabricadas en planta, extendidas y compactadas en una pista de ensayo acelerado de pavimentos. A continuación, se extrajeron testigos y se ensayaron para conocer su módulo de rigidez y resistencia a fatiga. Tanto los resultados de laboratorio como tras la fabricación en planta y puesta en obra mostraron que el comportamiento de mezclas HWMRA es comparable al de mezclas calientes convencionales. Dicha conclusión puede aportar confianza a este tipo de mezclas sostenibles promoviendo su mayor utilización.

Diseño y fabricación de un prototipo a escala de una cámara con variación de humedad y temperatura para curado de concretos de activación alcalina elaborados a partir de mezclas de escoria siderúrgica y cenizas volantes

“…The chamber has different response types depending on the kind of test being performed; where the temperature control system used has a damped sub behavior with a steady-state error for the temperature of about ± 2.5 ° C and humidity to ± 2.5% RH, this is due in principle to the control operation, the ability to respond of the caloventor to the reference and the thermal properties and hydrophobic material [13], [14].…”

“…When the chamber is operating exclusively with humidity control, it is obtained a transient response over-damped and steady-state error of about ± 5% RH, because the humidification system is slow to respond since the structure has properties optimum sealing with the hydrophobic properties of the material, allow to maintain stable conditions in the chamber with minimum loss [14], [15].…”

Performance of High Rap Half-Warm Mix Asphalt

“…They concluded that the recycled mixture displayed higher mechanical resistance as a result of the partial blending of the fresh bitumen with the RAP containing aged bitumen. Lizárraga et al [14,15] analyzed the performance of HWMAs containing 70% and 100% RAP in the laboratory and in situ. They used a prototype plant for the manufacture.…”

Self-Healing Analysis of Half-Warm Asphalt Mixes Containing Electric Arc Furnace (EAF) Slag and Reclaimed Asphalt Pavement (RAP) Using a Novel Thermomechanical Healing Treatment

“…Therefore, many of the studies found in the literature review have focused on the heating and healing of mixtures containing only virgin (i.e., aggregates or fresh bitumen) and steel slag aggregates. In this sense, it has been suggested that HWRA technologies with recycled and slag aggregates are promising solutions to increase further environmental, technical, and economic benefits associated with the use of industrial by-products [64,65]. In this regard, González et al [42] concluded that mixtures with RAP and metal fibers have the potential to increase the self-healing effect on the cracked specimens when using microwave heating energy.…”