Publicações

Portuguese forests are mainly composed of hardwoods, which represent 69% of the forest area in 2010, being Blue gum (Eucalyptus globulus Labill.) the most abundant species (26%). The suitability of Blue gum for structural applications was demonstrated in previous studies. However, the most common uses are still related to the pulp and paper industry as well as energy production, mainly due to sawing and drying issues. The present paper describes a preliminary study on the potential application of non-destructive tests and analytical methods to predict the most important mechanical properties of glued laminated timber (glulam) beams made of Blue gum. The potential of mixed beams made of Blue gum and poplar was also analysed. The longitudinal vibration method and the transformed section method were considered. A total of 11 non-finger jointed full-scale glulam beams (7 of Blue gum and 4 mixed) were manufactured in the laboratory and tested for modulus of elasticity and bending strength assessment. After the bending tests, the density and moisture content of the beams were determined, and the bonding performance was checked by delamination and shear strength tests. Correlation coefficients were established between the predicted values and the experimentally assessed mechanical properties, indicating a huge potential of the predictive methods used. The mechanical properties of non-finger jointed beams tested were above the typical values found in the literature for the most common hardwoods available in European forest.

Reducing the cement content of concrete is of paramount importance towards sustainability, since its production process is highly energy-consuming and delivers massive CO2 emissions to the atmosphere. In this paper, the bond behaviour between steel and stainless-steel reinforcing bars and Low Binder Concrete (LBC), produced with approximately one half and almost one fourth of the minimum cement content prescribed in the standards, is experimentally investigated. Results show the compactness of the mixture to be the main parameter controlling bond development, more than the mixture compressive strength as suggested in published results and standards. A more compact and denser mixture increases the contact surface between the reinforcing bars and concrete, improving friction between both. LBC mixtures with lowered cement content, up to almost one fourth of the minimum recommended, can be used without jeopardizing the bond strength of reinforcing bars. LBC mixturespromise to be a fitting approach towards greater sustainability in the concrete production sector.

Reducing the cement content of concrete is of paramount importance towards sustainability, since its production process is highly energy-consuming and delivers massive CO2 emissions to the atmosphere. In this paper, the bond behaviour between steel and stainless-steel reinforcing bars and Low Binder Concrete (LBC), produced with approximately one half and almost one fourth of the minimum cement content prescribed in the standards, is experimentally investigated. Results show the compactness of the mixture to be the main parameter controlling bond development, more than the mixture compressive strength as suggested in published results and standards. A more compact and denser mixture increases the contact surface between the reinforcing bars and concrete, improving friction between both. LBC mixtures with lowered cement content, up to almost one fourth of the minimum recommended, can be used without jeopardizing the bond strength of reinforcing bars. LBC mixtures promise to be a fitting approach towards greater sustainability in the concrete production sector.

Among biological agents, insect attacks may cause severe degradation of timber structuresin the service life of buildings which leads to lower mechanical performance and, thus, maintenanceproblems over time. Additionally, compression perpendicular to the grain always features a weak spotwith respect to the long-term mechanical performance of timber members and joints. In the presentwork, the respective strength and elastic modulus were thus investigated for insect deterioratedwood. Following a standardized geometry, small samples degraded by anobiids were extractedfrom beams made of sweet chestnut wood (Castanea sativa Mill.) that were removed from service.Visual assessment of the external wood surfaces was then performed to identify areas infested byinsects. Afterwards, destructive monotonic compression tests were carried out perpendicularly tothe grain on the damaged area to determine the loss of compressive strength and elastic modulus.The experimental results showed that the loss of compressive strength and elastic modulus mightbe linearly correlated to the wood density loss for small samples infested by insects. Nonetheless,future work should focus on determining accurately the density loss in the insect-deteriorated partthrough non- or semi-destructive tests, in order to establish stronger relationships with the mechanicalproperties loss investigated.

In the present work, and for the first time, totally biosourced low-density particleboardswere produced using cardoon particles (a no added value by-product from the Portuguese cheese making industry), bound with a potato starch adhesive. Different starch/cardoon ratios (0.6, 0.8, 1 and 1.2) were tested and the effect of different bio-based additives (chitosan, wood fiber and glycerol) on the performance of the adhesive system was evaluated. The best result was obtained for a formulationwith a starch/cardoon mass ratio of 0.8, a chitosan/starch mass ratio of 0.05 and a water/starch mass ratio of 1.75. The particleboards produced had a density of 323 kg-m-3, internal bond strength of 0.35 N.mm-2 and thickness swelling of 15.2%. The values of density and internal bond strength meet the standard requirements of general-purpose lightweight boards for use in dry conditions according to CEN/TS 16368 specification. Moreover, the susceptibility of the formulations with best results was established against subterranean termites and one decay fungi.

There is a need for new solutions in wood protection against marine wood borers andtermites in Europe. A new solution could be the esterification of wood with sorbitol and citric acid(SCA) since these are inexpensive and readily available feedstock chemicals and have shownprotective properties against fungal wood degradation in earlier studies and preventedmacrobiological degradation, as shown in this study. Protection of wood products in the marineenvironment lacks available wood preservatives that are approved for marine applications. Termiteinfestation is opposed mainly by biocide treatments of wood. Several wood modification systemsshow high resistance against both marine borers and subterranean termites. However, the existingcommercialized wood modification products are costly. Both macrobiological forms of degradationrepresent a great threat for most European wood species, which are rapidly and severely degradedif not properly treated. This study investigated esterified wood in standard field trials againstmarine wood borers, and against subterranean termites in laboratory trials in a no-choice and choicetest. The treatment showed good resistance against wood borers in the marine environment afterone season and against subterranean termites in the laboratory after eight weeks. The low termitesurvival rate (SR) in the no-choice test during the first week of testing indicates a mode of actionthat is incomparable to other wood modification treatments.

Due to its average mechanical properties, poplar, a fast-growing species, has been disfavored compared to stronger species for several decades. Wood-based products may help changing that perspective and thus, poplar has been gaining its marketshare for structural uses. A state-of-the-art review concerning the use of poplar to produce glued laminated products, with special focus on the use of Portuguese poplar, is presented. The Portuguese forest produces a great variety of species. Themost common poplar species found in this country are Populus x canadensis, P. nigra L., and P. alba L. Despite its limited availability, and the market hesitation on its structural application, recent studies on poplar grown in the Portuguese forestshowed its suitability for structural purposes. Glued laminated timber (GLT) beams made with this species revealed a very promising mechanical behavior. Bending strength tests evidenced a ductile behavior on more than 70% of the beams, whichmotivated deepening the study on the raw material used to produce those beams. To predict the mechanical behavior of such beams, a 3D numerical model was developed. The numerically predicted results were compared with the experimental ones,showing very good agreement between both approaches.

O betão com baixa dosagem de ligante (LBC - low binder concrete na denominação anglo-saxónica) e o betão com baixa dosagem de cimento com agregados reciclados (LCRAC - low cement recycled aggregate concrete ) são alterativas eco-eficientes ao betão de cimento Portland com agregados naturais por apresentarem um menor impacto ambiental. Para contribuir para o estudo da viabilidade de aplicação estrutural do LBC e do LCRAC, apresentam-se neste artigo os resultados obtidos numa campanha experimental de ensaios de arrancamento (pull-out tests), realçando o desempenho obtido ao nível da relação entre a tensão de aderência e o deslizamento do varão de aço. Os resultados experimentais foram comparados com as propostas de previsão existentes e apresenta-se uma primeira proposta de lei para descrever a relação tensão de aderência-deslizamento, considerando a compacidade, os agregados reciclados, o diâmetro do varão e a respetiva área relativa das nervuras transversais. A influência positiva da compacidade na aderência foi validada através da comparação dos resultados obtidos com os resultados decorrentes da proposta existente no Model Code 2010.

In this article, an assessment method toestimate the residual strength of pine structural ele-ments degraded by anobiids is presented. This novelmethod was developed in the laboratory to be usedin situ and is based on the strength required to withdrawa screw on the surface of degraded timber. Samples ofdegraded maritime pine (Pinus pinaster Ait.) weresubmitted to micro-computed tomography (l-XCT) toquantify density loss. This parameter is highly corre-lated with mechanical properties thus central for theassessment of timber structural capacity. Density lossvalues have been correlated with both screw withdrawalforce and shear parallel to the grain strength showingsignificant relationships between these parameters.Using these correlations, the density loss of a degradedelement and its shear strength parallel to the grain viathe screw withdrawal force can be estimated enabling avalid quantitative assessment of the timber elementsresidual strength and, therefore, contributing to reduceunnecessary replacement, to boost eco-efficient inter-ventions and to provide foundations required to performexperimental modelling tests.

O risco refere-se à probabilidade de ocorrerem danos causados pela manifestação de um determinado perigo, sendo função da perigosidade, da exposição (de pessoas e bens) e da vulnerabilidade dos elementos expostos face a esse perigo.Um componente essencial da avaliação do risco è a análise da perigosidade associada aos perigos identificados num dado território, sejam de origem natural ou decorrentes da ação humana. Outro componente essencial é a análise dos elementos (pessoas e bens) expostos aos perigos, bem como as características que contribuem para a suavulnerabilidade - ou a sua resiliência em situação de acidente grave ou de catástrofe. Nesta comunicação dá-se conta de alguns estudos desenvolvidos pelo LNEC nos domínios da avaliação da perigosidade e da vulnerabilidade sísmica das construções, da perigosidade de agitação costeira e risco de galgamentos costeiros e da avaliação da vulnerabilidade de edifícios aos incêndios florestais.

Bridge falsework systems, in particular those constituted by proprietary modular framed systems of metallic elements connected by special couplers are frequently used in structural engineering works. The popular Cuplok® system was chosen for this study. A total of 192 tests were carried out divided in four types of joints. For each type of joint, several pa-rameters, critical to define the joints

The fire performance of timber structures is largely influenced by the behaviour of theconnections. Current structural fire design rules for timber connections, according toEN 1995-1-2 [1], are based on a limited number of tests and are only valid for fire resistances up to 30 minutes, for unprotected bolted or dowelled (with d < 12 mm) connections with side member of wood. Improving the fire resistance of timber connections has been the goal of several studies [2

The fire performance of timber structures is largely influenced by the behaviour of theconnections. Current structural fire design rules for timber connections, according toEN 1995-1-2 [1], are based on a limited number of tests and are only valid for fire resistances up to 30 minutes, for unprotected bolted or dowelled (with d < 12 mm) connections with sidemember of wood.Improving the fire resistance of timber connections has been the goal of several studies [2

Survey of existing timber structures often includes the need to allocate mechanical properties to structural timber members. This task has to take into account the huge variability of timber's properties (within and between species), characteristic that differentiates this material from other structural materials (e.g. concrete and steel). For many decades, and still now, the application of visual strenght standards is the main or only procedure used for this task. despite the large number of other non and semi-destructive technique developed their regular application to in situ assesment of timber's mechanical properties is still almost non-existent. The present paper discusses possible ways to use and combine information from visual grading standards and non and semi-destructive techniques to predict the reference properties of timber members in service. The discussion has in mind studies conducted over the last years and the information provided by different guidelines, standards or papers recently published.

Historical centers are important elements of our cities, representing their historyand evolution. Many cities are facing the problem of having several vacant and degraded buildings needing intervention to avoid collapses. Also several examples of unforeseen events, like earthquakes, tsunamis, floods, etc., have severely damaged important historical cities. Beyondthe risk of losing built heritage, these buildings represent public danger for citizens. Thus, in post-disaster scenarios it is urgent to protect historical buildings in order to prevent the propagationof damages.This paper presents a first efficiency assessment of using wood based systems in buildings needing urgent consolidation or damaged after disasters. Being light, easy to handle and install, as well as providing the sufficient load carrying to prevent the evolution of the damage and losses, wood and wood-based elements can be associated in different arrangements providingquick construction systems for the consolidation of damaged constructions.

This paper presents the laboratory work performed with the purpose of understanding the mechanical performance of 340x20x20 mm maritime pine wood samples degraded by rot fungi when treated with a biocide product followed by consolidation through impregnation with a polymeric product.Four commercially available products were used: a water-based biocide, BC, a solvent-based biocide, X, an acrylic consolidant, PB (PB 72), and an epoxy-based consolidant, E. Seven sets of specimens each one having a varied range of fungal degradation were prepared. Thenthe product combinations were applied by brush to six sets of specimens (E, X-E, BC-E, PB, X-PB, BC-PB) of which one was left untreated for control, 0-0. Finally all sets were subjected to static bending strength test until rupture. Results showed that the acrylic and epoxy-based products lead to increased mechanical capacity ofthe consolidated wood up to 100% in some cases in specimens with 70% of MOE loss. The results presented the same order of magnitude for both wood consolidants. The previous application of biocide did not have a significant impact in the behavioral pattern of the consolidant: a markedimprovement of the bending strength of the degraded specimens after treatment and consolidation. These results demonstrated the feasibility of combining biocide/consolidation products, and provideindications of interest to the application of this technique to extend the lifespan of wood elements moderately degraded by fungi in old buildings.

A parafina tem sido utilizada ao longo dos tempos como proteção superficial da madeira. A sua utilização por impregnação para melhorar a resistência à biodegradação é recente. Pretendeu-se com este estudo determinar a eventual melhoria das principais propriedades mecânicas da madeira com este tratamento. A madeira utilizada nos testes foi madeira sã de Pinus pinaster Ait. A madeira foi impregnada com parafina a diferentes níveis, usando um processo de quente-frio, partindo de madeira húmida e seca, com 2 h em banho quente a 160oC e 10 ou 30 min em banho a 60oC. O ganho de massa, a tensão de rotura à flexão e o módulo aparente de elasticidade (MOE) num ensaio a 3 pontos e a dureza Jankja foram determinados com recurso a uma máquina de testes universal. Como esperado, a madeira húmida absorveu mais parafina com ganhos de massa entre 72% e 100%. A madeira seca apresentou ganhos de massa entre 46% e 51%. A tensão de rotura à flexão aumentou com o aumento de massa de parafina, atingindo um acréscimo de 39% em relação àa madeira não tratada para a madeira com um ganho de massa próximo de 80%. Em relação aoMOE, houve também um aumento, embora menor, atingindo cerca de 13% para ganho de massa de cerca de 80%. Verificou-se um aumento da dureza Janka com oganho de massa, atingindo cerca de 40% de aumento para a madeira com 80% de ganho de massa. Cnclui-se que a impregnação com parafina não deve ser feita com madeira completamente seca, além do conhecido aumento de resistência à biodegradação, esta impregnação melhora também várias propriedades mecânicas da madeira como a sua resistência à flexão e dureza, o que lhe pode atribuir um maior valor acrescentado

Apresenta-se uma proposta de investigação para o desenvolvimento de uma metodologia de apoio ao projecto de arquitectura de habitação em madeira. A construção em madeira vem assumindo uma importância crescente face aos desafios actuais. A sua utilização pode contribuir para a redução dos impactes ambientais da construção ao nível do consumo de energia, da emissão de gases com efeitos de estufa e da produção deresíduos. Em alguns países, a tradição consolidada proporciona uma aceitação generalizada da construção em madeira para habitação. Nos últimos anos, várias empresas nacionais do sector da construção em madeiradesenvolveram um leque variado de soluções de habitação unifamiliar. Esta é uma tipologia com uma procura significativa em Portugal. No entanto, o abrandamento da economia nacional e a consequente redução daprocura obrigou já algumas empresas de construção e projecto a procurarem novos mercados. Os países do espaço Lusófono são parceiros naturais na troca de experiências e conhecimento pelo que podem serdestinatários privilegiados de soluções, tanto ao nível da construção como ao nível do projecto. Em Portugal, apesar do avanço dos últimos anos, a construção em madeira estrutural para habitação é um domínio reservado ainda a uma minoria de especialistas, projectistas e construtores. O papel do arquitecto no primeiro contactocom o cliente, na definição do programa base e nas primeiras opções construtivas ao nível de projecto é de extrema importância. Grande parte das escolhas iniciais determina o desenvolvimento posterior do projecto e amaior ou menor adequação da obra aos dados do programa e do contexto. Neste sentido considera-se importante desenvolver uma metodologia de apoio ao projecto de arquitectura. Esta metodologia visa informar os arquitectos sobre as decisões cruciais a tomar em projecto, em função dos sistemas de construção disponíveis e da singularidade de cada situação. Assim, apresenta-se neste artigo o quadro teórico de uma metodologia deapoio ao projecto de arquitectura, a desenvolver e concretizar num estudo em curso.

A round robin involving 15 European participants was set up in 2006. The round robin consists of both a field test according to the double layer test method and a laboratory test with two different preconditioning methods. When comparing EN 84 preconditioning (two weeks water leaching with natural preconditioning (1 year in field, above ground) according to CEN/TS 15397, no significant difference could be noted for untreated controls, thermally modified wood or CCA impregnated wood. However, for wood treated with a metal-free organic preservative, a clear difference could be seen where much of the efficacy seen after EN 84 preconditioning is lost when natural preconditioning is used instead. In the field tests, the control pine performs similar in all fields whereas both thermally modified and preservative treated wood performs much better in the Nordic fields than in the Mid- and Southern European fields. The thermally modified wood performs almost as poor as the controls in the Southern European fields, whereas the organic preservative treated wood performs well in these fields. In the six Mid-European fields, the organic preservative treated and thermally modified wood performs equally poor but much better than the controls. The best compliance between field performance and laboratory test results is obtained when comparing the average results from the field tests with results from EN 113 tests with Postia placenta after natural preconditioning according to CEN/TS 15397.

Timber is one of the most used materials in the roofs and floors of monumentalconstructions in Portugal. The geometry is defined by elements that occupy a limited and well defined part of the tri-dimensional space, with a clear evidence of the hierarchy of the components.Timber elements are often visible, which allows easier conservation, identification of the wood species, characterization of details and evaluation of deterioration.Complex timber structures, such as those belonging to the roofs of large monuments, are often not easy to understand in a expedite way. As the coverings of monuments as cathedrals, public buildings, mansions or villas show very complicate features, not easy to be understood during thefirst inspection. This is not only due to the fact that the system is very elaborate and to the large number of members but also due to continuous changes and repair past works, mostly with additional stiffening or propping. The typical result of the history of the construction is the increasein the number and the heterogeneity of the members, together with a multiplicity of connections and diversity of supports. This means that the original must be distinguished from the additions and thereplacements. This complexity makes the field of conservation of historical timber structures not only a challenge but a field much in need of modern research.The objective of this paper is to present some of the Portuguese experience in this field, showing how the rehabilitation solutions can be supported by the inspection techniques and by an extensiveknowledge about the constituent material from which the structure was made, both from the mechanical point of view and from the physical point of view. A number of case studies will be presented to illustrate common conservation problems, and design problems as well as the possibilities and limitations of several solutions and to discuss the suitability of several intervention methods.

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O Museu da Academia das Ciências de Lisboa possui uma preciosa xiloteca assinada pelo Mestre dos marceneiros portugueses, José Aniceto Rapozo contendo 1213 amostras de madeiras do Brasil e 12 de outras origens. A sua importância no progresso do conhecimento dos recursos florestais do Brasil naviragem dos séculos dezoito e dezanove conduziu ao estudo em curso. Dada a devastação verificada em vastas áreas florestais brasileiras, surgem dificuldades por certas espécies poderem ter distribuiçãogeográfica diferente (com eventual extinção, geral ou localizada), por insuficiência do material de comparação, e por ambiguidade das designações comerciais.Foi possível identificar esta xiloteca como uma de quatro encomendadas a Aniceto Rapozo pelo Príncipe Regente. A análise das amostras de madeira e a informação documental mostram que a colecçãotem por base uma remessa de 5008 amostras de madeiras do Brasil enviada em 1784 para o Arsenal Real do Exército, em Lisboa, pelo Vice-Rei do Brasil, Luís de Vasconcellos e Souza.O valor científico do conjunto é evidenciado pela identificação botânica das espéciesrepresentadas. Na situação actual, a identificação das espécies florestais representadas na amostragem foiinteiramente conseguida em 14% dos casos, conseguida mas ainda por confirmar em 27%. Dado o carácter preliminar deste estudo, os seus resultados serão ulteriormente publicados com mais pormenor. Among the Lisbon Academy of Sciences Museum collection there is a valuable xylarium by theleading Portuguese master cabinet-maker José Aniceto Rapozo (1756-1824), comprising 1213 wood samples from Brazil plus 12 from elsewhere. This collection is most important since it allows us to improve the knowledge on Brazilian forest resources by the end of the eighteenth century and thebeginning of the next. This study aims to establish its historical framework and scientific value. Owing tooverexploitation and even devastation of very large forest areas in Brazil, difficulties for our study aroseeither as some species may have now a different geographical distribution (and eventually may have underwent local or general extinction), by lack of adequate comparison material, or because of ambiguityof the commercial names.Results so far obtained allowed us to recognize the xylarium as one of the four commanded Rapozo by the Regent Prince, later King João VI (1767-1826). Taking into account the wood samples analyses as well as bibliographic data it is possible to conclude that the collection was prepared from a set 3 of 5008 Brazilian wood samples sent to the Royal Arsenal in Lisbon in 1784 by the Brazil

This work collects information about laboratory tests to evaluate the properties of agro-industrial wastes used for thermal insulation building materials considering them individually and in composits. It focuses on bio-susceptibility, as one of the main aspects to consider for bio-based building products.

Innovation in structures and construction materials demands a more accurate performance analysis during the life cycle. In addition, climatic changes pose new challenges to civil infrastructures that were not so relevant in the past. In most cases, the traditional test methods cannot accurately assess the complex phenomena involved in durability. The modern and complex factors require a different approach to durability analysis. The purpose of this chapter is to present innovative durability tests on construction materials: wood; rammed earth, cob and unfired blocks; natural stone; bituminous binders and mixtures; and Fibre Reinforced Polymers (FRP) to concrete bonded connections. Most of these tests concern the accelerated simulation of the main phenomena involved in durability performance

Laboratory tests were carried out to define production parameters of innovative eco-efficient composites made up of hazelnut shells as aggregate and a sodium silicate solution as adhesive. The aim was to maximize the content of bio-aggregates and minimize the amount of adhesive, guaranteeing the feasibility of producing samples. Therefore, after preliminary testing, the percentages of hazelnut shells and the sodium silicate solution were kept constant: 70% and 30% of the total volume, respectively. However, the characteristics of the considered composites did not allow the production of uniform samples. The sodium silicate solution was not rapidly absorbed by the bio-aggregates; during the drying process, it was deposited on the bottom side of the samples. The uniformity of the samples is required to guarantee a correct evaluation of their performance and future homogeneous panels. Hence, different production parameters were investigated, such as drying at T

The durability of construction materials is a key concern and can be related to different actions such as weathering conditions outdoors enhanced by climatic change, chemical and biological attack, abrasion, and other conditions of service over time. Frequently, several actions develop simultaneously, making it difficult to reproduce in situ conditions in laboratory. Furthermore, testing to assess durability depends largely on the nature of the material itself or on the way it has been assembled with other materials. The ageing techniques to assess long-term durability performance of construction materials are based on accelerated durability tests, which include, for example, thermal stress, freeze

This paper presents an overview of research carried out to assess the bonding suitability of Portuguese timbers.Most work developed in the last decades has focused Maritime pine timber, due to its traditional use in building construction, good mechanical properties and availability. Untreated, as well as preservative treated Maritime pine have been studied, as its impregnability allows deep treatment suitable for applications in Use Classes 3 and 4.Recent results on bonding preservative treated Maritime pine wood are discussed.Preliminary results regarding other species that are becoming available in the Portuguese market are also presented, as an attempt to reduce pressure on Maritime pine timber as well as to seek more valuable alternatives for their traditional uses.

No presente trabalho apresentam-se os resultados mais relevantes obtidos num programa experimental desenvolvido no LNEC com o objetivo de caracterizar a aderência dos varões nervurados do tipo A500NR SD existentes no mercado, fundamentalmente para melhorar a modelação do comportamento dos elementos de betão armado de zonas críticas de estruturas inseridas em zonas sísmicas.O programa experimental desenvolvido pretende simular as condições de aderência existentes num varão horizontal de uma ligação viga-pilar e tem como principais variáveis varões de dois diâmetros frequentemente utilizados (16 e 25 mm), dois níveis diferentes de área relativa das nervuras (A e B) e duas classes de betão (C1 e C2), ambos representativos do betão utilizado nas construções mais relevantes.Os resultados obtidos quer nos ensaios monotónicos quer nos ensaios cíclicos apontam para um decréscimo da tensão de aderência com o aumento do diâmetro da ordem dos 10%. O aumento da área relativa das nervuras transversais traduz-se num incremento da tensão máxima de aderência da ordem dos 15%, com uma redução do deslizamento que ronda os 15%. Nesse sentido, este estudo propôs que, no caso dos varões com maior área relativa das nervuras, a tensão de aderência máxima possa variar entre 2,35 e 2,65 vezes a raiz quadrada da resistência do betão à compressão e que o patamar onde a tensão de aderência é máxima se situe entre 0,5 e 1,5 mm de deslizamento.Explorou-se também o fenómeno da entrada em cedência da armadura tendo-se concluído que, em provetes que pretendem simular as condições de aderência existentes num varão horizontal de uma ligação viga-pilar, a entrada em cedência da armadura conduz a uma redução da tensão de aderência máxima inferior a 10%, quer regime monotónico quer em regime cíclico.

O presente trabalho de investigação refere-se à conservação de elementos estruturais de madeira medianamente degradados por fungos em edifícios antigos. Propõe-se estudar a compatibilidade entre produtos de tratamento e de consolidação por impregnação, aplicados sequencialmente. A avaliação do processo foi realizada maioritariamente em laboratório e na óptica do desempenho mecânico conjunto da madeira e produtos aplicados, por intermédio de ensaios físico-mecânicos destrutivos e não destrutivos e também por ensaios mecânicos não destrutivos realizados in situ. Foram utilizados produtos comerciais, aplicando-os às espécies de madeira correntemente encontradas nos edifícios antigos da zona de Lisboa: Pinho bravo e Casquinha. Procedeu-se à avaliação mecânica de madeira nova e antiga, em estado são e degradado; ao desenvolvimento de um método de medição da profundidade de penetração de produtos de tratamento; à avaliação da capacidade consolidante de madeira degradada por produtos poliméricos fluidos e à avaliação da sua actuação conjunta, estudada com e sem envelhecimento artificial. Os resultados obtidos indicaram significativos aumentos de capacidade mecânica da madeira degradada, quando submetida a tratamento e consolidação Este trabalho desenvolve, assim, uma proposta de solução para a madeira que não se encontra sã, mas que ainda possui capacidade resistente, não necessitando, por isso, de ser removida. O processo de tratamento e consolidação promove resistência aos agentes biológicos e, simultaneamente, recuperação de alguma resistência mecânica da madeira, conferindo-lhe capacidade para continuar em serviço.

Subterranean termites from the genus Reticulitermes are an important pest ofwood in service throughout southern Europe and elsewhere. For effective termitecontrol with long term protection but minimal environmental damage, newintegrated approaches to termite management are needed. Baiting-based systemsseem to be promising non-traditional methods for termite control, targeting thecolony as a whole. However, control through baiting is only feasible when it isknown that the toxicant can be transferred to all the colonies foraging on theinfested area and also throughout each individual colony. Accordingly, the workdescribed is specifically designed to achieve a better understanding of thedistribution and delimitation of colonies within a population of Reticulitermes,with parallel insights into foraging behaviour and colony organization.Initially, the species/subspecies spectrum present within the notionalReticulitermes group in Portugal was reassessed. It was shown that Reticulitermesgrassei is the only species encountered. Foraging activity was then assessed in anexperimental woodland site over two successive annual cycles, both by thesampling of natural lying dead wood and by a standard baiting grid. R. grasseiseem to select wood with larger diameter, with an apparent preference for materialalready decayed by fungi. Both termite and fungal attack on wood seems to bepromoted by higher moisture levels, such as prevail in larger litter items andduring seasonal rains. Termites were unable to detect and direct their foragingtowards sound wood in laboratory conditions, suggesting that the network ofinfochemical signals is more complex than just volatiles emanating from soundwood. Mark-release-recapture (MRR) was used to delineate foraging groups,which were then allocated to their parent colonies by the use of microsatellitemarkers. The results suggest that resource sharing is a facultative behaviour,specifically when food is not a limiting factor for colony development. Theimplications of all these findings for bait technology and protocols are discussed,with reference to the local population ecology of Reticulitermes.

The project CircularBuild -

Relatório final do projeto PTDC/ECM/099121/2008

O presente trabalho apresenta um projecto de versão portuguesa da Norma Europeia EN 10002-2, e insere-se numa série de estudos programados pelo autor, enquanto coordenador da normalização nacional no domínio dos ensaios mecânicos, físicos e não-destrutivos de materiais metálicos.O texto do projecto de norma apresentado consiste na versão final de uma proposta redigida pelo autor, na sequência dos estudos efectuados ao nível da Comissão Técnica de Normalização competente.

O presente trabalho apresenta um projecto de versão portuguesa da Norma Europeia EN 10002-5, e insere-se numa série de estudos programados pelo autor, enquanto coordenador da normalização nacional no domínio dos ensaios mecânicos, físicos e não-destrutivos de materiais metálicos.O texto do projecto de revisão apresentado consiste na versão final de uma proposta redigida pelo autor, na sequência dos estudos efectuados ao nível da Comissão Técnica de Normalização competente.

O presente relatório descreve a participação do LNEC no programa europeu de intercomparação de calibrações de forças

O presente trabalho apresenta um projecto de revisão da Norma Portuguesa NP 850 (1985)

O presente trabalho apresenta um projecto de revisão da Norma Portuguesa NP 386 (1965)

O presente trabalho apresenta um projecto de revisão das Normas Portuguesas NP 449 (1966)

O presente trabalho apresenta um projecto de revisão da Norma Portuguesa NP 450 (1966)

O presente trabalho apresenta um projecto de Norma Portuguesa relativo ao ensaio de dilatação de anéis de tubos metálicos, e insere-se numa série de estudos programados pelo autor, enquanto coordenador da normalização nacional no domínio dos ensaios mecânicos, físicos e não-destrutivos de materiais metálicos, com a finalidade de preencher lacunas da Normalização Portuguesa neste domínio que a indústria e as instituições ligadas ao controlo da qualidade considerem ser mais urgente colmatar.O texto apresentado consiste na versão final de uma proposta redigida pelo autor, na sequência dos estudos efectuados ao nível da Comissão Técnica de Normalização competente.

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