Carlos Chastre

Carlos Chastre
Universidade NOVA de Lisboa | NOVA · Department of Civil Engineering (CED)

PhD, Associate Professor

About

153
Publications
27,628
Reads
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2,433
Citations
Citations since 2016
79 Research Items
2093 Citations
20162017201820192020202120220100200300
20162017201820192020202120220100200300
20162017201820192020202120220100200300
20162017201820192020202120220100200300

Publications

Publications (153)
Article
The enhancement of the mechanical behaviour of reinforced concrete (RC) columns with regard to axial compression is an up-to-date concern, namely if the strengthening of existing structures is to be considered. In view of this, external confinement with FRP systems has been tested in order to become a feasible technique, since it seems to have impo...
Article
Full-text available
Structural design relies essentially on tests made on cylinders of small size to estimate the probability of failure of prototype members, since full-scale testing of structures to determine their strength is not feasible. The confidence that such scale modeling deserves in terms of representation of actual behavior needs careful examination, due t...
Article
Building stones, particularly sandstone and granite, are very important in the building elements of Portugal’s historical and cultural heritage. Experimental research, based on uniaxial compressive tests, was carried out on selected representative samples of lithotypes of rocks used in historic built heritage, with a view to evaluating the compress...
Article
Full-text available
The paper analyses different analytical and numerical solutions for the debonding process of the FRP-to-concrete interface on shear tests with the FRP plate submitted to a tensile load in one of its ends. From the point of view of the state of the art, two different ways of finding the bond-slip curve from experiments are discussed and analysed. Es...
Article
The retrofit of reinforced concrete columns with FRP jackets has received considerable attention in recent years. The advantages of this technique compared to other similar techniques include the high strength-weight and stiffness-weight ratios of FRP (Fibre Reinforced Plastics), the strength and ductility increase of RC columns confined with FRP j...
Article
Full-text available
Fibre-reinforced polymer materials (FRP) are increasingly used to reinforce structural elements. Due to this, it is possible to increase the load-bearing capacity of polymer, wooden, concrete, and metal structures. In this article, the authors collected all the crucial aspects that influence the behaviour of concrete elements reinforced with FRP. T...
Article
This paper presents an experimental study about the fire behaviour of reinforced concrete (RC) slabs strengthened with carbon fibre reinforced polymer (CFRP) strips, applied according to three different techniques: externally bonded reinforcement (EBR); near-surface mounted (NSM), and continuous reinforcement embedded at the ends (CREatE), a new te...
Article
This study develops an easy-to-conduct numerical calculation method to assess the effect of Textile Reinforced Mortar when used as externally bonded flexural strengthening technique in low-grade reinforced concrete beams from ancient structures (aged between 60 and 100 years old). Using materials main mechanical characteristics and the beams dimens...
Article
Full-text available
This study was numerically focused on the non-linear behaviour of glass fibre reinforced polymer (GFRP) reinforced concrete beams with different amounts of transverse reinforcement. The mid-span deflection of concrete beam cannot effectively be restricted using higher amount of flexural GFRP bars, owing to their low deformability factor. So, the us...
Article
Epoxy composites have been widely used to properly bond the carbon fiber reinforced polymers (CFRPs) applied in the structural strengthening of reinforced concrete members. However, due to the thermal wear the epoxy composite loses its mechanical properties when exposed to sunlight heating, especially at temperatures above the glass transition temp...
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This paper contributes to the definition of design clauses for coarse recycled aggregate concrete. One of the main reasons for scepticism towards recycled aggregate concrete is the perceived notion that the heterogeneity of recycled aggregates may increase the uncertainty of the behaviour of concrete. Therefore, the paper uses structural reliabilit...
Article
This paper concerns the design of lap splice lengths for ribbed steel reinforcement bars embedded in concrete produced with coarse recycled concrete aggregates. Recycled aggregates are weaker and typically lead to concrete with lower tensile strength. Both aspects change the model uncertainty of bond strength formulae and a major topic of the paper...
Article
Full-text available
Mechanical anchorage devices have the potential to efficiently improve the bond behavior of Carbon Fiber-Reinforced Polymers (CFRP) Externally Bonded (EB) onto steel with an adhesive. Existing relevant studies, however, have been very limited. Against this background, experimental and numerical studies on the double overlapped CFRP-to-steel bonded...
Article
Basalts are a common lithology found beneath Lisbon and are the predominant rocks of the Volcanic Complex of Lisbon (CVL) (72 Myr). These basalts exhibit variable texture and composition. Given the vast extent of the CVL, which encompasses Lisbon and its surroundings, and the establishment of several present and future engineering works upon this r...
Article
A combination of fiber-reinforced polymer (FRP) reinforcing bars and steel fibers can be employed in locations of a structure with reinforcement congestion instead of the conventional combination of steel rebars and stirrups. In this study, first, the shear performance of the FRP bar-reinforced concrete beams containing steel fibers and crumb tire...
Article
An innovative system for the flexural strengthening of Reinforced Concrete (RC) structures designated as Continuous Reinforcement Embedded at Ends (CREatE) is presented in this research work. The main characteristics and procedures for the application of this new strengthening technique are described. To evaluate the performance and efficiency of t...
Article
Adhesively bonded joints have been widely used by engineers to solve problems in different industries. Despite recent studies which have helped with the design and application of these joints, there are still several uncertainties that justify empirical implementation in practice. One main aspect is the rigorous understanding of the performance of...
Article
The model uncertainty of the shear resistance equations of three design codes {the current Eurocode 2 (2004), Model Code (2010), and the final draft of the Eurocode 2 (2020)} was investigated for coarse natural and recycled aggregate concrete beams. Databases of beams with and without shear reinforcement were made with clearly defined criteria. The...
Article
Full-text available
The study of the mechanical behavior of building stones is traditionally supported by destructive compression tests carried out on representative specimens. However, in order to respect the monuments’ integrity, the study of the mechanical behavior of stones can be based mostly on physical properties obtained from non-destructive tests (NDT). For t...
Article
The durability of adhesively bonded Fiber Reinforced Polymers (FRP) and concrete substrates has been the subject of recent studies. The degradation of the bonded interfaces conjugated with other factors that affect the interface strength may compromise the potentialities of using FRP in Externally Bonded Reinforced (EBR) concrete structures. Howeve...
Article
Ao longo da sua vida útil os edifícios históricos estão sujeitos a alterações de uso, a agentes ambientais e a diferentes ações como assentamentos do solo, incêndios, inundações ou sismos, para os quais podem não estar preparados. Além disso, a falta de manutenção contínua ajuda a colocar grande parte desse património em risco devido a problemas es...
Conference Paper
Full-text available
An analysis on the effect of the incorporation of coarse recycled concrete aggregates on the bond strength between concrete and embedded steel reinforcement is presented. The model's uncertainty of the Level I provision of the anchorage length of fib Bulletin 72 on ribbed steel/recycled aggregate concrete bond is quantified. Afterwards, reliability...
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The bias factor of the Eurocode 2 [CEN (European Committee for Standardization) (2008). Eurocode 2: Design of Concrete Structures-Part 1-1: General Rules and Rules for Buildings] and ACI 318 [ACI (American Concrete Institute) (2014). Building Code Requirements for Structural Concrete and Commentary] flexural resistance models of reinforced concrete...
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An investigation on the scatter of code-type constitutive models that relate compressive strength (fc) with tensile strength (fct) and Young’s modulus (Ec) of standard concrete specimens is presented. The influence of the mix design on the accuracy of the fc vs. fct and fc vs. Ecrelationships is discussed, with emphasis on the lithological type and...
Article
This paper evaluates and compares the statistics of compressive strength data from three Portuguese ready-mixed concrete plants. A hierarchical model showed that different groups of concrete strength records are not statistically equivalent, even if they were produced in the same plant and using the same concrete composition. This finding is relate...
Article
The estimation of the long-term durability of adhesively bonded interfaces between Fiber Reinforced Polymers (FRP) and concrete substrates is crucial because degradation potentiates FRP premature debonding. One of the main reasons for mistrusting the use of FRP composites is the premature debonding phenomenon, which, associated to degradation, has...
Conference Paper
Full-text available
Os sistemas de reforço por colagem exterior têm sido alvo de várias abordagens, não só do ponto de vista do tipo de material a utilizar, como também sob o ponto de vista da técnica mais eficiente a seguir. As fibras reforçadas com polímeros (FRP) têm sido, no último par de décadas, alvo de investigação exaustiva, tendo-se verificado que esses siste...
Article
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 pur...
Article
Full-text available
This paper investigates the effect of recycled coarse aggregate incorporation on the relationship between 150 mm cubic and Փ 150 mm cylindrical compressive strength (the reference strength of standards) by comparing data from recycled and natural aggregate concrete compositions in which both cubes and cylinders were tested. A conversion factor from...
Article
The degradation mechanisms of bonded joints between CFRP laminates and steel substrates under severe environmental conditions require more durability data and studies to increase the database and better understand their causes. Studies on bond properties of double-strap CFRP-to-steel bonded joints with two different composite materials as well as a...
Article
This work presents the results and the main conclusions of a series of experimental tests carried out to evaluate the efficiency of post-installed stainless steel reinforcement on the flexural strengthening of Reinforced Concrete (RC) T-beams when the bonding techniques EBR (Externally Bonded Reinforcement), NSM (Near Surface Mounted) and MA-EBR (E...
Article
The monitoring of structures has undergone important advances with the improvements of digital cameras available on the market. Thus, the Digital Image Correlation (DIC) technique has become a viable way of studying engineering problems. Recently it has been used in the debonding failure process between the reinforcement and the substrate. The meth...
Article
Full-text available
Based on a few experimental results available in the literature, this work presents a simple analytical approach that allows the study of the long-term behaviour of CFRP-to-concrete interfaces under an initial sustaining load. Only the elastic regime is studied, which means that the interfacial maximum bond stress and maximum slip are never exceede...
Article
Full-text available
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 su...
Conference Paper
Full-text available
Fibre Reinforced Polymer (FRP) can be used as a strengthening material in several types of structures built with different materials, such as concrete, timber, steel, aluminium or clay masonry. Contrary to fasteners, the bond technique currently used to connect the FRP composites to the substrate avoids stress concentrations. The knowledge on the p...
Article
Pseudo-cyclic and cyclic loading were applied to CFRP-to-steel bonded joints built with two different CFRP laminates. In this paper, the strength capacity and bond-slip curves are presented and compared. The modes of failure are also described and associated with the types of material used, and the observed performances are correlated. The analysis...
Article
Concrete structures Externally Bonded Reinforced (EBR) with Fibre Reinforced Polymers (FRP) have been studied and used since the end of the last century. However, several issues need to be better studied in order to improve performance. The influence of size of anchorage plates used on Reinforced Concrete (RC) structures strengthened with EBR FRP c...
Chapter
Sandstones are widely used in the building elements of the world's stone monuments. Alveolization due to salt crystallization-dissolution is the most important degradation pattern found on the Middle Ages’ sandstone façades of St. Leonardo's Church in Portugal. An outstanding case of widespread distribution of deep and large alveolization patterns...
Article
Full-text available
The paper presents a nonlinear analytical solution for the prediction of the full-range debonding response of mechanically-anchored FRP composites from the substrate. The nonlinear analytical approach predicts, for any monotonic loading history or bonded length the relative displacements (or slips) between materials, the strains in the FRP composit...
Article
The effective stress transfer between the fiber reinforced polymers (FRP) and the steel substrate is crucial for the successful retrofit of existing steel structures with FRP composites. However, there are no standard tests for FRP-to-steel interfaces, wherefore different test configurations have been used in recent years to assess the bond behavio...
Article
Full-text available
The durability performance of stainless steel makes it an interesting alternative for the structural strengthening of reinforced concrete. Like external steel plates or fibre reinforced polymers, stainless steel can be applied using externally bonded reinforcement (EBR) or the near surface mounted (NSM) bonding techniques. In the present work, a se...
Chapter
Earthquakes, soil settlements, traffic vibrations, and air pollution are some of the actions that can affect historic old buildings. Besides these, the lack of continuous maintenance puts a large part of this heritage in risk due to structural problems that reduce their own safety and that of their users. The preservation and risk mitigation of bui...
Article
Full-text available
Carbon Fiber Reinforced Polymer (CFRP) composites have a large potential for strengthening and retrofitting steel parts but due to their premature debonding from steel, further data and research are still required for wider application in such situations. In the present paper, the bond characteristics of CFRP-to-steel joints in pull-pull loaded con...
Conference Paper
Full-text available
Compressive stresses created by lateral external pressure on the laminates are an important factor on the success of the use of mechanical devices to anchor the externally bonded reinforcement (EBR). A program of double shear tests that also imposed normal stresses on GFRP plates bonded to a concrete surface is described and a bond-slip model brief...
Article
Full-text available
The bonding between two different materials or between same materials is a quite popular method. Unlike fastener joints, it avoids undesirable stress concentrations and doesn't demand an intrusive application to ensure the good performance of the joint. However, depending on the configuration of the adhesively bonded joint, its performance responds...
Article
Weathering imposes vital effects on stony monuments. Mostly, the degree of weathering is determined by simple test results, ignoring simultaneous effects of various weathering factors. Hence, the main purpose of this study is to develop prediction models with fuzzy inference systems to determine the weathering degree of the Persepolis stone, using...
Article
The main goal of the present research work is to characterise a unidirectional fibre reinforced grout (UFRG), developed as an alternative material to strengthen RC structures using small thickness jacketing. A high performance cementitious grout reinforced with continuous and unidirectional non-woven steel fibre mat has been developed for this purp...
Article
Full-text available
A set of three old suspended timber floors were flexurally-strengthened with Carbon Fiber Reinforced Polymers (CFRP) strips in order to investigate the effectiveness of externally bonding FRP to their soffits. The specimens were from an old building and 740 mm-wide bands were transferred to the laboratory in order to be tested in a 4-point bending...
Article
Full-text available
The strengthening of structures such as columns, beams, arches or slabs with Fibre Reinforced Polymers (FRP) has been the focus of several studies. However, the studies dedicated to the FRP debonding phenomenon of curved bonded joints affected by elevated temperatures are surprisingly limited and no studies on this topic are known, at present, to u...
Article
This paper presents a comparative evaluation of efficiencies of different accelerated ageing tests (freeze-thaw, thermal shock, salt crystallization, dissolution and wetting-drying) and fuzzy inference system in predicting weathering degrees of some monument stones from three historical sites (Anahita Temple, Anobanini reliefs and Eshkaft-e Salman...
Article
Full-text available
Fiber Reinforced Polymers (FRP) is a recent technique to strengthen timber structures and the studies available discussing the debonding between these materials are limited. Therefore, the bond assessment between FRP composites and timber substrates is a topic that needs clarification. The present work analyses the debonding process between Carbon...
Chapter
Sandstone rocks are important reservoirs of water, petroleum, and gas. In the Western Region of Portugal, there are surface and near surface sandstone reservoirs close to salt formations. Sandstone samples collected from these surface reservoir formations were used to an experimental research, which was carried out in the laboratory of NOVA. An aut...
Conference Paper
Full-text available
Desde que o reforço estrutural começou a utilizar materiais de matriz polimérica reforçada com fibras (FRP) que o fenómeno do descolamento prematuro dos compósitos de FRP da superfície colada tem merecido especial atenção de vários autores. O conhecimento do processo de descolamento completo da ligação CFRP/betão ganhou assim, algum destaque nos úl...
Conference Paper
Full-text available
O reforço estrutural com materiais de matriz polimérica reforçada com fibras (FRP) em e.g. pilares, vigas, lajes ou arcos, tem sido objecto de vários estudos. No entanto, a avaliação da aderência em ligações coladas em superfícies curvas são ainda insuficientes, não se conhecendo trabalhos que se debrucem sobre os efeitos da temperatura. Sendo conh...
Conference Paper
Full-text available
Neste artigo apresentam-se e analisam-se um conjunto de ensaios realizados em vigas de betão armado reforçadas com armaduras pós-instaladas de aço ou de FRP, incluindo os referentes a uma nova técnica (CREatE) desenvolvida na FCT NOVA. Os resultados experimentais permitiram concluir que a técnica CREatE possibilita aumentos de resistência e ductili...
Article
Full-text available
The design of timber beams has strict limits when it comes to the Serviceability Limit States (SLS) either in short-term or in long-term deflections. In order to face this aspect efficiently, the increase of the cross section of the beams might be considered as a solution. However, the prohibitive increase of the costs associated to this solution o...
Conference Paper
Full-text available
A reabilitação de estruturas de betão armado com compósitos de FRP tem tido uma grande aceitação em especial devido às excelentes características de durabilidade dos materiais compósitos, ao seu baixo peso e às suas elevadas prestações mecânicas. Contudo, o comportamento elástico-linear dos compósitos de FRP e a sua forma de aplicação pode originar...
Conference Paper
Full-text available
O reforço à flexão de vigas de betão armado tem apresentado uma evolução com tendência para soluções onde são utilizadas armaduras à base de materiais compósitos de fibras de Carbono, Vidro, Basalto ou Aramida, aplicadas com as técnicas Externally Bonded Reinforcement (EBR) ou Near Surface Mounted (NSM). No entanto, o comportamento elástico-linear...
Conference Paper
Full-text available
The strengthening of reinforced concrete structures with FRP materials has received a considerable increment in recent years due to their durability characteristics, high strength-weight and stiffness-weight ratios of FRP compared to other materials. An experimental program was conducted in order to analyze the behavior of different structural solu...
Article
Five experimental cyclic tests were carried out on reinforced concrete (RC) rectangular columns with rounded corners, different conditions (new and damaged), and different strengthening systems, which included confinement through carbon fiber-reinforced polymer (CFRP) jackets, anchor dowels, highstrength repair mortar, and external longitudinal sta...