Publications

Export 5 results:
Sort by: Author Title Type [ Year  (Desc)]
2019
Micaelo, Rui, José Neves, Rui Lopes, and Alexandra Jesus. "A Different Perspective on the Production and Application of Warm Mix Asphalt Under Unfavorable Temperature Conditions." Transportation and Geotechniques: Materials, Sustainability and Climate. Eds. Manik Barman, Musharraf Zaman, and Jia-Ruey Chang. Cham: Springer International Publishing, 2019. 20-32. Abstract

Warm mix asphalt (WMA) is produced by a variety of technologies at lower temperatures that enable to gain important environmental and social benefits and, in consequence, to contribute to a more sustainable transportation infrastructure. The producer usually defines the temperatures used in WMA production. However, some references suggest the increase of temperature in order to allow a longer time to transport or to compact in cases of unfavourable weather conditions, mainly under low temperatures. The objective of this paper is to analyse the feasibility of producing WMA at the same temperatures of hot mix asphalt (HMA) guaranteeing an adequate compaction, and final performance in service. The paper describes a laboratory study to investigate the properties of a WMA using different additives and varying the mixing and compaction temperatures. The effect of production temperatures on the performance of the WMA was evaluated through binder drainage (production phase), volumetric properties (compaction phase), and resistance to permanent deformation (service phase). The paper also presents a numerical study on the time available for paving WMA under unfavourable climatic conditions. Results demonstrated that it is possible to produce WMA at high temperatures without problems of binder drainage, during transport, and of performance in service if adequate compaction is achieved. In fact, the production temperatures influenced the compaction phase. However, it is possible to increase the temperature without negatively affecting the required volumetric properties. The rut depth of the permanent deformation test was mostly influenced by the air-voids of the compacted WMA and the binder. From the numerical study, it was concluded that the time available for in situ compaction increased substantially when WMA was paved at higher temperature. However, in cases of low air temperature and thin layer, the increase of temperature may not be sufficient to obtain the desired level of density or air-voids.

Carl, C., P. Lopes, M. Sá da Costa, G. Canon Falla, S. Leischner, and R. Micaelo. "Avaliação do efeito do filer no envelhecimento do betume." 9º Congresso Rodoviário Português. Lisboa, Portugal 2019. Abstract

n/a

Carl, C., P. Lopes, M. Sá da Costa, G. Canon Falla, S. Leischner, and R. Micaelo. "Comparative study of the effect of long-term ageing on the behaviour of bitumen and mastics with mineral fillers." Construction and Building Materials. 225 (2019): 76-89. AbstractWebsite

This study aims to evaluate the effect of mineral fillers on bitumen ageing. Two different bitumens and four mastics were investigated in the unaged and long-term aged states, based on different properties (consistency, rheology, fatigue resistance and ductility). Mastics stiffened less due to ageing treatment than bitumens, especially with granite filler. However, the results of the performance tests were not definitive regarding the effect of the filler. Aged bitumen showed greater fatigue resistance and higher specific energy of ductile fracture than unaged bitumen, whereas the mastics showed minor variations in the specific energy of ductile fracture with ageing treatment, which is indicative of less ageing, but the fatigue resistance decreased significantly in mastics with one of the bitumens.

2013
Simões, F., F. Lopes, A. Ferreira, and R. Micaelo Aplicação a Portugal do novo método de dimensionamento de pavimentos rodoviários da AASHTO. 7º Congresso Rodoviário Português. Lisboa, 2013.
2011
Micaelo, Rui, Maria Colás, Arnaud Mazars, Julio Arias, Gillaume Crauzzo, and Laurent Lascroux. "Técnicas Rodoviárias Adaptadas às Mudanças Climáticas – Selecção e Avaliação." XVI Congresso Ibero-Latinoamericano do Asfalto. Rio de Janeiro, Brasil: IBP, 2011.