Publications

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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

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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.

2018
Biscaia, Hugo, Rui Micaelo, Carlos Chastre, and João Cardoso. "Cyclic Loading Behaviour of Double Strap Bonded Joints with CFRP and Aluminium." Key Engineering Materials. 774 (2018): 36-41. AbstractWebsite

The adhesively bonded joints behaviour under cyclic loading is not yet well understood due to its inherent complexity. Numerical approaches appear, therefore, as the easiest way to simulate such mechanical behaviour. In this work, double strap bonded joints with Carbon Fibres Reinforced Polymers (CFRP) and aluminium are numerically simulated and subjected to a cyclic loading history. In the numerical simulation, the Distinct Element Method (DEM) is used and it is assumed cohesive bi-linear bond-slip models with local damage of the interface. The evaluation of the bonded joints under cyclic loading is made by comparing the results with those simulated with a monotonic loading.

Pereira, L., A. C. Freire, M. Sá da Costa, V. Antunes, L. Quaresma, and R. Micaelo. "Experimental study of the effect of filler on the ductility of filler-bitumen mastics." Construction and Building Materials. 189 (2018): 1045-1053. AbstractWebsite
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2017
Micaelo, R., A. Guerra, L. Quaresma, and M. T. Cidade. "Study of the effect of filler on the fatigue behaviour of bitumen-filler mastics under DSR testing." Construction and Building Materials. 155.Supplement C (2017): 228-238. AbstractWebsite

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2015
Micaelo, R., A. Pereira, L. Quaresma, and M. T. Cidade. "Fatigue resistance of asphalt binders: Assessment of the analysis methods in strain-controlled tests." Construction and Building Materials. 98 (2015): 703-712. AbstractWebsite
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2014
Biscaia, Hugo C., Rui Micaelo, João Teixeira, and Carlos Chastre. "Numerical analysis of FRP anchorage zones with variable width." 67 (2014): 410-426. AbstractWebsite

AbstractThe use of Fibre Reinforced Polymers (FRP) has recently become widespread in the construction industry. However, some drawbacks related to premature debonding of the FRP composites from the bonded substrates have been identified. One of the solutions proposed is the implementation of mechanical anchorage systems. Although some design guidelines have been developed, the actual knowledge continues to be rather limited. Thus, designers and researchers have not yet achieved any consensus on the efficiency of any particular anchor device in delaying or preventing the premature debonding failure mode that can occur in Externally Bonded Reinforcement (EBR) systems. This paper studies the debonding phenomenon of FRP anchoring systems with a linear variable width, with a numerical analysis based on the Distinct Element Method (DEM). Combined systems with constant and variable width are also discussed. The FRP-to-parent material interfaces are modelled with a rigid-linear softening bond–slip law. The numerical results showed that it is possible to attain the FRP rupture force with a variable width solution. This solution is particularly attractive when the bonded length is shorter than the effective bonded length because the strength of the interface can be highly incremented.

Biscaia, Hugo C., Rui Micaelo, João Teixeira, and Carlos Chastre. "Delamination process analysis of frp-to-parent material bonded joints with and without anchorage systems using the distinct element method." Composite Structures (2014). AbstractWebsite

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2013
Costa, Gonçalo, Rui Micaelo, and Adelino Ferreira Análise dos critérios de aceitação/rejeição do caderno de encargos tipo obra para pavimentação. 17.º Congreso Ibero-Latinoamericano del Asfalto. Antigua, Guatemala, 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.