Helena Gervasio

University of Coimbra | UC · Department of Civil Engineering

The study provides assessment of the penetration of climate change induced carbonation in the concrete cover of the existing buildings in the EU Member States. It estimates the time for on-set of corrosion due to depleting of the cover of the reinforcement, and evaluates the repair costs under the moderate emissions scenario RCP4.5, and under the e...

Ever since their creation, a lot of work has been done to improve the Eurocodes’ rules by making them better estimators of the actual structural behaviour. However, reliability throughout the Eurocodes, and sometimes even within one design rule, is not uniform. For that reason, it is necessary to produce evidence of the reliability of the current E...

This presentation sums up the work on the digital workflow for the design of steel industrial buildings. The workflow tackles the lack of flexibility of the current programs and the lack of cooperation between branches, affiliating a transition from a siloed to a more collaborative workflow. In order to condense the workflow and enhance its capabil...

Ziel des im Folgenden vorgestellten Forschungsprojekts ist die Entwicklung von fünf Gebäudehüllsystemen aus Stahl mit niedrigem Kohlenstoffgehalt und innovativem Einsatz von Holzfaserdämmung. Es werden drei Sandwichelemente (Schrägdach, Flachdach, Fassade), eine doppelschalige Fassade und eine Fassadenverkleidung (Kassetten) entwickelt. Das Projekt...

Abstract The INCSEB project is aimed at developing 5 ultra-low carbon envelope systems made in steel and that incorporate innovative use of wood fiber insulation. The systems under development are: 3 sandwich panels (cladding, pitch & flat roofing), 2 claddings (double skin & façade with plank). INCSEB includes tests to study various behaviors: mec...

The built environment is already facing severe consequences related to climate change. Considering the durability of structures, the increase of carbon-dioxide (CO2) concentration and changes on temperature and relative humidity may accelerate carbonation-induced corrosion, thus affecting the service life of reinforced concrete structures. Several...

All over the world, the number of civil engineering structures, particularly bridges with long service periods, has been increasing. The most common evidences of damages are the presence of corroded metallic elements and cracks in structural details due to the fatigue phenomenon. A large number of cases were found in which fatigue cracks were detec...

p>The impact of climate change on ambient temperature and relative humidity along with the present CO2 levels are speeding the corrosion process of reinforced concrete structures. The alarming cost of the associated reduction of the service life of structures, which is estimated to cost 3% to 4% of the Gross Domestic Product (GDP) of industrialized...

The palafitic timber constructions of the central Portuguese coastline are an example of the adaptation to site-specific conditions (climate and sand landscape morphodynamics) using the available endogenous resources. Thus, in a context of environmental awareness and climate change, it is relevant to understand their features/strategies and how the...

The work outlines recent EU policies supporting the sustainability and climate resilience of infrastructure and buildings. It evaluates the expected variations in climatic factors causing corrosion, provides a state of the art review on climate change induced corrosion of reinforced concrete and steel structures, and presents recent works on the c...

Nominated for the Professor Eduardo de Arantes e Oliveira Award at XII Conference on Steel and Composite Construction in Coimbra 2019 This paper presents the results of a numerical parametric study that investigated the M‐V interaction behaviour of box‐girder bridge deck specimens. The study made use of an advanced numerical model that was previous...

In this paper, the results of the numerical parametric study are presented, in which the M-V interaction behaviour of box-girder bridge deck specimens was investigated. For this study, an advanced numerical model was used, previously calibrated against the experimental results. Based on the numerical results and the existent rules for the trapezoid...

Open-loop earth-air heat exchangers (EAHE) can be used as a passive contribution to reduce the energy demand of buildings for heating and cooling, by providing a thermal pre-conditioning of the required ventilation air. This paper aims to numerically assess the influence of three parameters on the overall thermal performance of an EAHE system for r...

The increase in global environmental problems requires more environmentally efficient construction. Vernacular passive strategies can play an important role in helping reducing energy use and CO 2 emissions related to buildings. This paper studies the use of glazed balconies in the North of Portugal as a strategy to capture solar gains and reduce h...

In the Portuguese context, the life cycle assessment of building materials is still in its infancy. So far, there is only a small number of Environmental Product Declarations (EPDs) available, all target for industrially-based materials. Although vernacular earthen materials are seen as ecological materials, with low potential environmental impacts...

In this paper, a comprehensive experimental study on cylindrically curved steel panels is presented, in order to characterize the structural behavior of cylindrically curved panels as individual members under uniform compression. Therefore, 32 full-scale compression tests on both stiffened and unstiffened simply supported curved panels were perform...

In this paper, the results of the numerical parametric study are presented, in which the M-V interaction behaviour of box-girder bridge deck specimens was investigated. For this study, an advanced numerical model was used, previously calibrated against the experimental results. Based on the numerical results and the existent rules for the trapezoid...

Bridges have a significant role in society but are often massive structures requiring a high amount of materials, leading to high consumption of natural resources and high costs. In this respect, the use of high-strength steel (HSS) may represent a significant advantage as it enables to reduce the quantity of materials required for a structure to f...

In this paper, a comprehensive numerical study is performed with the aim to investigate the buckling and the post-buckling behavior of simply supported cylindrically curved steel panels subjected to pure shear. The main objective is to understand the influence of geometrical parameters, such as curvature and aspect ratio, on the elastic critical lo...

This main goal of this research is to characterize the structural behavior of a cylindrically curved steel panel as an individual member under compressive stresses. Therefore, six panels, both unstiffened and stiffened, were experimentally examined. The thickness of the panels is constant and equal to 4 mm, whereas the radius is equal to 20 m. One...

It is of high importance to develop innovative strengthening and rehabilitation operations for bridges whose design life is coming to an end. A case study concerning the centenary Portela road bridge in Coimbra is addressed. In situ experiments were performed in order to obtain a modal identification of the structure. The data was used to elaborate...

Traffic patterns increasing and the degradation of existing roadway steel bridges due to poor maintenance has led to the need of an assessment deciding whether to retrofit or to supply a structure replacement. This paper focusses on the rehabilitation of steel truss bridges in order to extend the lifetime of such bridges. Two case studies are prese...

Injection bolts have been used to replace faulty rivets on strengthening operations of old riveted steel bridges. This technology has been essentially tested for its quasi-static or creep behaviour and there are very few studies concerned the assessment of its fatigue resistance. This paper presents an experimental program developed to evaluate the...

The main objective of the research program is to develop solid knowledge on the structural behavior of curved steel panels for optimized applications in steel and composite bridges. Moreover, the new findings in this field should spur and contribute to the extension of the EN 1993-1-5 design methodology, which is still limited only to the design of...

In this paper, an extensive numerical study is performed with the aim to investigate the post-buckling behavior of simply supported cylindrically curved steel panels subjected to a pure shear load. The main objective is to understand the influence of geometrical parameters, such as curvature and aspect ratio, but also it is aimed to examine how the...

In this paper, an extensive numerical study is performed with the aim to investigate the elastic buckling behavior of simply supported cylindrically curved steel panels subjected to a pure shear load. The main objective is to understand the influence of geometrical parameters, such as curvature and aspect ratio, but also of the edge in-plane constr...

In Portugal, there is a lack of quantitative studies on the thermal performance of earthen buildings. This paper aims at contributing to this research context by studying site-specific strategies, and the thermal performance and comfort conditions of a rammed earth building located in southern Portugal. The study is based on objective and subjectiv...

The use of natural resources for building construction represents, in terms of mass, one of the biggest challenges in resource consumption. On the other hand, construction and demolition waste is one of the most important waste streams generated in the EU, about 25% - 30% of all waste generated in the EU, and consists of numerous materials with pot...

Previous researches have shown that the material production stage and the operational stage of bridges (when traffic is affected by maintenance activities) are the stages which have the major impact in the lifecycle performance of bridges. In this respect, the use of high strength steel (HSS) in structures may represent a significant advantage sinc...

The Raw Materials Scoreboard is an initiative of the EIP on raw materials. It presents relevant and reliable monitoring information that informs government, industry, and other stakeholders in line with the overarching objectives of this EIP. The Scoreboard is published every two years, with the 2018 Scoreboard being the second edition of the serie...

The main objective of this research project is to develop solid knowledge on the structural behavior of curved steel panels for optimized applications in steel and composite bridges. Moreover, the goal is to extend the EN 1993-1-5 design methodology for transversally curved panels subjected to various in-plane load cases. For that purpose, two iden...

A consciencialização ambiental sobre o setor da construção tem evidenciado diversos problemas no que à eficiência energética e aos impactes ambientais concerne. Assim, o setor está numa fase de mudança de um paradigma pouco preocupado com o contexto climático e os impactes ambientais dos edifícios, dependente de sistemas mecânicos e de materiais co...

The main objective of this research project is to develop solid knowledge on the structural behavior of curved steel panels for optimized applications in steel and composite bridges. Moreover, the goal is to extend the EN 1993-1-5 design methodology for transversally curved panels subjected to various in-plane load cases. For that purpose, two iden...

The work presented in this paper is part of a research project aiming for the development of a performance-based approach for sustainable design, focusing on the efficient use of natural resources over the lifetime of buildings. The proposed approach requires the set of benchmarks to provide a consistent and transparent yardstick for the environmen...

Earth-to-air heat exchanger is an efficient complement to the space heating and cooling systems. An earth-to-air heat exchanger system consists of a set of subterranean pipes leading outdoor air to a ventilation room and by collecting geothermal energy saves some energy. This article presents testing of an earth-to-air heat exchanger installation i...

Cylindrically curved plates are increasingly used in steel construction. In particular, there is a clear trend for their use in box-girder steel bridges with curved bottom flanges. However, there is a gap in standards dealing accurately with these type of structural elements under several ar-rangements of loadings and boundary conditions. This pape...

Different strategies can be used to perform reparations and reinforcements of ancient bolted and riveted metallic bridges. As the riveting process is not currently a common practice, it requires proper equipment and skilled workers. Another solution is the use of welding. However, the weldability of old steels is poor. Bolts are very attractive alt...

Screw connections have an important role in the performance of Light Steel Framing (LSF) construction systems. In this paper, the behaviour LSF panels using screw connections subjected to lateral load is discussed and further insights are provided on the behaviour of such panels by experimental tests and numerical analysis. Therefore, the main aim...

The main goal of this research is to characterize the structural behavior of panels as the individual members under compressive stresses. Two unstiffened curved panels subjected to pure compression are experimentally and numerically examined. The thickness of the panels is constant and equal to 4 mm, whereas the radius is equal to 20 m. The results...

Resumo. Os sistemas de ventilação com permutadores de calor solo-ar (EAHE, do inglês "Ea-rth-to-Air Heat Exchangers") são constituídos por uma rede de tubos enterrados, por onde o ar exterior é forçado a circular, tirando proveito da grande inércia térmica do solo e reduzindo, assim, as necessidades energéticas para climatização dos edifícios. Nest...

As pontes são infraestruturas de vital importância para a sociedade, desta forma, a aplicação da metodologia de Análise de Ciclo de Vida (ACV) a este tipo de estruturas tem merecido nos últimos anos a atenção dos diversos parceiros ligados à construção. Do desenvolvimento do projecto de investigação Sustainable Steel-Composite Bridges in Built Envi...

The main goal of this research is to characterize the structural behavior of panels as the individual members under compressive stresses. Two unstiffened curved panels subjected to pure compression are experimentally and numerically examined. The thickness of the panels is constant and equal to 4 mm, whereas the radius is equal to 20 m. The results...

Among the strategies that can be implemented for repairing and strengthening operations of old metallic structures, using structural adhesives to improve the fatigue strength of steel connections has been considered as a good solution. It is expected that the adhesive help to distribute and to transfer the load over a large area, thus reducing stre...

Resumo. A construção modular leve em aço (LSF, do inglês "Light Steel Framing"), é uma alternativa eficiente aos tradicionais métodos de construção in-situ. Um dos métodos da cons-trução modular, consiste na assemblagem de painéis (LSF) pré-fabricados e transportados para o local da construção. Na produção destes painéis em LSF, é usual a utilizaçã...

A construção vernácula carateriza-se pela relação próxima com as condições locais do meio em que se insere (clima, materiais, economia, cultura, etc.). Os territórios continental e insular de Portugal são marcados pela heterogeneidade entre si pelo que deu origem ao desenvolvimento de diferentes tipos de arquitetura vernácula. As construções vernác...

The improvement of the use of renewable energy sources, such as solar thermal energy, and the reduction of energy demand during the several stages of buildings' life cycle is crucial towards a more sustainable built environment. This paper presents an overview of the main features of lightweight steel-framed (LSF) construction with cold-formed elem...

In light of current European guidelines towards resource efficiency in the construction sector, a performance based approach is herein introduced taking into account environmental criteria, namely the sustainable use of resources. The proposed approach for sustainable design is in line with the safety assessment criteria of the European standards f...

This paper compares the axial force and bending moment design procedures of Eurocode 3 part 1.1 and the Brazilian Standard NBR8800. This comparison was performed through a series of practical design examples that were executed according to EC3 pt. 1.1 [1] and NBR 8800 [2]. This strategy led to an assessment of some critical design issues present in...

In order to assess sustainability of buildings, environmental, economic and social aspects should be addressed. Within the evaluation of the social criteria, regarding a building in the use stage, the standard EN 15643–3:2012 defines, as a general methodology, a list of performance categories to be addressed. General guidelines for the evaluation o...

The influence of climate on vernacular architecture is widely recognised. In the case of the Mediterranean Sea, its influence on climate ranges a wide variety of territories and cultures. Therefore, it is relevant to study how the climatic factor has modelled vernacular architecture in those territories and if there are common features. In this exp...

A última transposição para a legislação portuguesa da diretiva europeia sobre o desempenho energético de edifícios (EPBD), aumentou consideravelmente os requisitos exigidos tanto a edifícios novos como a reabilitações. Nos edifícios antigos, as características arquitetónicas e dos materiais existentes condicionam as soluções disponíveis. A solução...

Buildings have a critical role in the support of the basic needs of society. However, they consume large amounts of natural resources and are responsible for equally high environmental burdens and consumption of energy. Therefore, the safety design of buildings and other construction works should be considered together with the environmental assess...

The design of steel structures classically consists of a two-step analysis and verification procedure: internal forces and displacements are first evaluated based on the principles of equilibrium and compatibility; subsequently, these internal forces and displacements are compared against corresponding resistance, stiffness and ductility values to...

This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book addresses a specific part of the Eurocodes relevant for steel construction. It introduces general aspects such as the basis of design, material properties and geometric characteristics and tolerances. Steel construction combines a...

According to the general framework established in European Standard (EN) 1990 for the safety of structures, the safety of steel members at ultimate limit state is ensured by applying partial safety factors to the various characteristic values of resistance. For steel members, the following three failure modes are considered: resistance of cross sec...

Plastic design of steel structures may assume different degrees of complexity and sophistication. It is often used in the design of pitched-roof portal frames. The methods of plastic analysis can be based on: the static theorem or maximum principle; the kinematic theorem or minimum principle. This chapter exemplifies the relevant aspects of plastic...

The first step in the design of a steel structure is the evaluation of internal forces and displacements for the various load combinations. This chapter presents and discusses procedures for the design of steel structures within the framework of elastic analysis, complemented by the presentation of a real design example. Elastic design of steel str...

In the evolution of vernacular buildings, different strategies have been developed for their adaptation to the surrounding environment. The climate-responsive strategies implemented in vernacular architecture from different regions have the potential for being further developed and could be adapted in answer to contemporary needs. Therefore, based...

Fatigue failures are of concern for steel bridges due to the likelihood of the steel to deteriorate under variable stresses, being recognised as the major cause of failure in metallic bridges. Residual life calculations of existing bridges in operation should take into account fatigue as a progressive damaging mechanism. The S-N approach is widely...

Different strategies can be implemented in the repairing and strengthening operations of old riveted steel bridges. Riveting is no longer common practice, consequently finding good equipment and skilled riveters is difficult. The use of welding may not be considered due to the poor weldability properties of the old steel. Regarding high strength fr...

Currently, sustainable development and the search for green and renewable energy sources are two of the top priorities of humankind. As it is known, the construction industry has a major role to the global economy, but is also one of the most relevant regarding waste production and resource depletion. For example, buildings have an important share...

The assessment of the sustainability of buildings embraces environmental, economic and social criteria. In the framework of recent European standards developed under CEN/TC 350, the first generation of the standards for the assessment of life cycle social criteria covers only the use stage (information modules B1 to B7). The categories of social pe...

Resumo. As construções com estrutura em aço enformado a frio apresentam habitualmente baixa inércia térmica. Com o objetivo de mitigar esta potencial desvantagem foi desenvolvido um painel inovador para as fachadas dos edifícios, que permite também o armazenamento das águas pluviais recolhidas na cobertura dos mesmos. Dada a capacidade de armazenam...

The constant increase in the wind power production leads to the need of higher wind towers, which brings up some questions regarding the effectiveness of tubular towers and respective foundations. This work focuses on the comparative structural design, life cycle behaviour and costs of onshore concrete shallow foundations for tubular wind towers (W...

Sustainable Development has become an important task nowadays. In the urban level, is paramount to create sustainable cities, which represents a balance solution in the environmental, social and economic factors. The construction sector has developed methodologies to assess sustainability at different levels. However at an urban level, there are fe...

The present JRC report contains state-of-the-art training material on the structural design of steel buildings, with emphasis on worked examples. The technical papers here presented focus on specific parts of the structural design, namely basis of design, modelling of structure, design of members, connections, cold-formed steel, seismic and fire de...

In the context of sustainability, life cycle approaches are becoming increasingly popular for the assessment of potential impacts of a product or a system, from raw materials production to decommissioning and end-of-life processes. In relation to highway bridges, lifetime analysis implies consideration of the way the bridge is maintained over the l...

O Departamento de Engenharia Civil e a Escola de Arquitetura da Universidade do Minho, em conjunto com o Departamento de Engenharia Civil da Universidade de Coimbra, organizaram o Seminário “reVer: Contributos da arquitetura vernácula portuguesa para a sustentabilidade do ambiente construído”, que teve lugar na Fundação Manuel António da Mota (Merc...

Das zweite Handbuch basiert auf Handbuch I "Entwurf von Anschlüssen zwischen Stahl und Beton", in welchem die Forschungsergebnisse des RFCS Forschungsprojektes INFASO RFS-CR-2012-00022 "New Market Chances for Steel Structures by Innovative Fastening Solutions between Steel and Concrete" und des Nachfolgeprojekts RFS2-CT-2012-00022 "Valorisation of...

Dieses Handbuch fasst die gewonnenen Forschungsergebnisse des Forschungsprojektes INFASO RFS-CR-2012-00022 "New Market Chances for Steel Structures by Innovative Fastening Solutions between Steel and Concrete" und des Nachfolgeprojekts RFS2-CT-2012-00022 "Valorisation of Knowledge for Innovative Fastening Solutions between Steel and Concrete" zusam...

In the first part of the paper the design of tubular towers and respective onshore foundations was addressed. The considered solutions were based on steel, concrete and hybrid steel-concrete tubular towers supporting multi-megawatt turbines of 2, 3.6 and 5. MW power with hub heights of 80, 100 and 150. m respectively. In this second part of the pap...