Coauthored Publications with: Lucio

Journal Article

Gião, R, Lúcio V, Chastre C.  2014.  Assessing the behaviour of RC beams subject to significant gravity loads under cyclic loads, 2//. Engineering Structures. 59:512-521., Number 2 AbstractWebsite

Gravity loads can affect a reinforced concrete structure’s response to seismic actions, however, traditional procedures for testing the beam behaviour do not take this effect into consideration. An experimental campaign was carried out in order to assess the influence of the gravity load on RC beam connection to the column subjected to cyclic loading. The experiments included the imposition of a conventional quasi-static test protocol based on the imposition of a reverse cyclic displacement history and of an alternative cyclic test procedure starting from the gravity load effects. The test results are presented, compared and analysed in this paper. The imposition of a cyclic test procedure that included the gravity loads effects on the RC beam ends reproduces the demands on the beams’ critical zones more realistically than the traditional procedure. The consideration of the vertical load effects in the test procedure led to an accumulation of negative (hogging) deformation. This phenomenon is sustained with the behaviour of a portal frame system under cyclic loads subject to a significant level of the vertical load, leading to the formation of unidirectional plastic hinges. In addition, the hysteretic behaviour of the RC beam ends tested was simulated numerically using the nonlinear structural analysis software – OpenSees. The beam–column model simulates the global element behaviour very well, as there is a reasonable approximation to the hysteretic loops obtained experimentally.
Gião, R, Lúcio V, Chastre C.  2019.  Gravity load effects on the behaviour of reinforced concrete beam critical zones subjected to cyclic loads, 2019/02/15/. Engineering Structures. 181:503-518. AbstractWebsite

The aim of the present study was to proceed to a numerical analysis of the gravity load effects on the behaviour of reinforced concrete beam critical zones when subjected to cyclic loads. A parametric study to assess the influence of different levels of gravity load on RC beam critical zones subjected to cyclic loading was carried out. For this purpose, assuming the level of gravity load as a variable parameter, a nonlinear numerical model of a beam-column connection, previously calibrated with experimental data, was used. In order to evaluate the gravity load effects in the global response, a numerical study of a RC frame system is also presented. The numerical results are analysed in terms of global hysteretic response, accumulated energy dissipation and equivalent viscous damping ratio. In this numerical study, it was observed that the hysteretic response depends on the load path. In the presence of higher gravity load levels, the structure hysteretic behaviour exhibits higher damage levels, associated to a failure mechanism corresponding to the formation of four span plastic hinges. Thus, the proper test procedure should involve the imposition of a reverse cyclic displacement history starting each cycle from the gravity load effects.

Magazine Article

Chastre, C, Lúcio V.  2014.  Evolução histórica, desenvolvimento atual e potencial futuro das torres de concreto pré-moldado para suporte de aerogeradores. Revista Concreto IBRACON, 75. :p.90-100.revista_concreto_ibracon_75_-_pg.90-100_-_fina.pdf
Lúcio, V, Chastre C.  2014.  Precast concrete wind tower structures. Historic development, current development and future potential, June 2014. CPI - Concrete Plant International, 3. :110-115., Number 3 Abstractcpi_03-2014_p144-149.pdfWebsite

The wind energy production is a growing industry and the energy produced is renewable and environmentally cleaner than most of the energy production systems. The supports of the wind energy generators may be built with precast concrete elements. The precast solutions for these structures are competitive in comparison to other structural systems. The evolution of the technology for wind energy production shows a clear need for larger wind turbines and longer blades and, consequently, taller towers. The experience also shows that precast concrete solutions increase their competitiveness as the tower height increases. Offshore wind farms have some advantages in relation to onshore ones, which explains recent investments in this area. Also in this case, the durability of concrete in the sea when compared to steel, gives advantages to precast concrete in relation to other structural solutions. This paper shows the evolution of the supports of the wind energy generators and the advantages of the use of precast concrete towers.

Thesis

Chastre Rodrigues, C.  1993.  Comportamento da Ligação Aço-Resina-Betão em Elementos Estruturais, 1993. Departamento de Engenharia Civil, Instituto Superior Técnico. MSc, Lisboa: Universidade Técnica de Lisboa Abstract1993_-_msc-_ist_-_carlos_chastre_-_comportamento_da_ligacao_aco-resina-betao_em_elementos_estruturais.pdf

The present work studies the behaviour of bonded steel plates to reinforced concrete elements, which can be used in the strengthening of concrete structural elements. Metallic expansion bolts can be added.The objective of this dissertation is to investigate the behaviour to monotonic actions and particularly to cyclic loading of steel-epoxy-concrete connection with expansion bolts. This cyclic action is of particular interest due to the strong seismicity of the Portuguese territory.The research is mainly based in experimental analysis. The caracterization of the materials was carried out. Six models of the steel-epoxy connection were tested with monotonic loading. Twenty six models of steel-epoxy-concrete bond were submitted either to monotonic or to cyclic actions.Besides the type of action, other parameters were studied in the steel-epoxy-concrete connection models.These were the bond geometry area, the type of concrete, the type of epoxy and connection - with or without metallic expansion bolts.A parametric study with a numerical model of finite elements, as well as a global analysis of the experimental tests of the steel-epoxy-concrete connection was carried out.