Artigos de Revista

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The paper reviews the importance and distinguishing character of façade azulejo frames as used in the region of Lisbon and presents and discusses the early frame patterns designed and produced by Fabrica Roseira in the mid-19th century.

Clayish earth-based mortars can be considered eco-efficient products for indoor plastering since they can contribute to improve important aspects of building performance and sustainability. Apart from being products with low embodied energy when compared to other types of mortars used for interior plastering, mainly due to the use raw clay as natural binder, earth-based plasters may give a significant contribution for health and comfort of inhabitants. Due to high hygroscopicity of clay minerals, earth-based mortars present a high adsorption and desorption capacity, particularly when compared to other type of mortars for interior plastering. This capacity allows earth-based plasters to act as a moisture buffer, balancing the relative humidity of the indoor environment and, simultaneously, acting as a passive removal material, improving air quality. Therefore, earth-based plasters may also passively promote the energy efficiency of buildings, since they may contribute to decreasing the needs of mechanical ventilation and air conditioning. This study is part of an ongoing research regarding earth-based plasters and focuses on mortars specifically formulated with soils extracted from Portuguese ‘Barrocal’ region, in Algarve sedimentary basin. This region presents high potential for interior plastering due to regional geomorphology, that promote the occurrence of illitic soils characterized by a high adsorption capacity and low expansibility. More specifically, this study aims to assess how clayish earth and sand ratio of mortars formulation can influence the physical and mechanical properties of plasters. For this assessment four mortars were formulated with different volumetric proportions of clayish earth and siliceous sand. The results from the physical and mechanical characterization confirmed the significantly low linear shrinkage of all the four mortars, as well as their extraordinary adsorption-desorption capacity. These results presented a positive correlation with mortars´ clayish earth content and are consistent with the mineralogical analysis, that confirmed illite as the prevalent clay mineral in the clayish earth used for this study. Regarding mechanical resistance, although the promising results of the adhesion test, the flexural and compressive strength results suggest that the mechanical resistance of these mortars should be slightly improved. Considering the present results the mortars mechanical resistance improvement may be achieved through the formulation of mortars with higher clayish earth content, or alternatively, through the addition of natural fibers to mortars formulation, very common in this type of mortars. Both those options will be investigated in future research.

To comply with the need to spread the culture of earthquake disaster reduction, we rely on strategies that involve education. Risk education is a long-term process that passes from knowledge, through understanding, to choices and actions thrusting preparedness and prevention, over recovery. We set up strategies for prevention that encompass child and adult education, as a bottom-up approach, from raising awareness to reducing potential effects of disruption of society. Analysis of compulsory school education in three European countries at high seismic risk, namely Portugal, Iceland and Italy, reveals that generally there are a few State-backed plans. The crucial aspects of risk education concerning natural hazards are starting age, incompleteness of textbooks, and lack of in-depth studies of the pupils upon completion of their compulsory education cycle. Hands-on tools, immersive environments, and learn-by-playing approaches are the most effective ways to raise interest in children, to provide memory imprint as a message towards a culture of safety. A video game, Treme

Consolidation treatment is a common practice in the field of conservation. However, when considering calcareous materials, there is a lack of efficient and durable consolidants. Colloidal dispersions of Ca(OH)2 nanoparticles, commonly known as nanolimes, can effectively recover the superficial loss of cohesion. However, they do not always guarantee in-depth mass consolidation. The aim of this paper is to give directions for improving in-depth deposition of nanolime dispersions when applied on limestone. A conceptual model, correlating the drying rate and the kinetic stability of nanolimes dispersed in different solvents, to the porosity of the limestone to be treated, is conceived. This model can help to select a suitable nanolime solvent depending on the substrate. *Manuscript Click here to view linked References Nanolimes were synthetized and dispersed in different solvents (ethanol, isopropanol, butanol and water). The morphology and size of the lime nanoparticles were studied by dynamic light scattering (DLS) and scanning electron microscopy (SEM-EDS). The kinetic stability of the nanolime was assessed by Uv-Vis spectroscopy. The porosity of the limestones were determined by mercury intrusion porosimetry (MIP), measuring as well their moisture transport properties. The model was validated by applying the different nanolimes to two limestones with very coarse (Maastricht limestone) and very fine porosity (Migné limestone). The absorption and drying kinetics and the deposition of the nanolimes within the treated limestones were investigated by phenolphthalein test, optical microscopy and SEM-EDS analysis. The results show that, as suggested by the model, less stable dispersions (as obtained by higher boiling point solvents e.g. butanol) are more suitable for coarse-pore limestones, while for fine limestones, more stable nanolime dispersions (as obtained by low boiling point solvents e.g. ethanol) should be preferred. Suggestions are given for further improvement and fine tuning of the nanolimes.

This article presents the results of an interlaboratory experimental study performed by 13 international research groups within the framework of the activities of the RILEM Technical Committee 225-SAP ‘‘Applications of Superabsorbent Polymers in Concrete Construction’’. Two commercially available superabsorbent polymers (SAP) were tested in terms of their influence on the freeze–thaw resistance of ordinary concrete. To test the robustness of the method, all participating laboratories used locally produced materials. Furthermore, following this aim, various accelerated methods were used to estimate the resistance of the concrete to freeze–thaw cycles. The effect of adding SAP was from insignificant toconsiderably positive in terms of improvement in material performance as determined by reduced mass loss after freeze–thaw cycles; only one participant observed worsening of the material behaviour. At the same time, due to the addition of SAP, a much less pronounced decrease in the dynamic Young’s modulus was observed as a result of freeze–thaw testing without deicing salt.

This paper proposes the use of the maturity method and of a two-phase composite models for the prediction of dam concrete modulus of elasticity.The methodology was validated with test results obtained from experimental in situ setup using creep cells placed in the dam's body, subjected to variable environmental conditions. It is shown that composite models can be used to predict the modulus of elasticity of in situ dam concrete based on the modulus of elasticity of the wet-screened concrete.

Debate-se a relação entre conhecimentos tecnológicos tradicionais e científicos como inovadora e fundamental para a conservação do património. Considera-se que a inovação não advém necessariamente do conhecimento científico, mas potencialmente de uma sábia articulação entre estes dois tipos de conhecimentos. Parte-se de um já longo processo de reflexão sobre a conservação do património com base em cal, conforme desenvolvido no LNEC a partir de projetos de investigação.

Flow monitoring in wastewater systems is used for system operation or for billing purposes, among others. Given the difficult measurement conditions, gaps in measurement series occur frequently and stakeholders need an appropriate method to estimate missing data. In data scarcity situations, mathematical modelling of the underlying physical processes may not be feasible and other methods are required. Partial least squares (PLS) regression is a multivariate statistical method suited to correlated data and has been frequently used for water quality estimates. PLS suitability for hourly and daily flow estimations was tested, based on previous flow and precipitation data, which urban water utilities currently monitor. Results were evaluated using proposed performance criteria and classes. The estimation errors were comparable to the ones obtained in physical process modelling. The application of the proposed method for flow estimation in sewers, in two common scenarios of wet and dry weather flows, is presented and discussed.

As estações de tratamento de águas residuais (ETAR) são atualmente alvo de esforços de melhoria do seu desempenho técnico, ambiental e económico. Empresas, reguladores e organismos de financiamento têm utilizado sistemas de avaliação de desempenho para apoiar as suas decisões. Neste contexto, o LNEC desenvolveu a 1.ª e a 2.ª geração do sistema de avaliação de desempenho de ETAR baseado em indicadores e índices de desempenho. Os valores de referência são elementos chave para o julgamento do desempenho e precisavam ainda de ser definidos para avaliar e melhorar o desempenho das ETAR em termos de, por exemplo, eficiência energética e gestão de lamas. Esta temática foi desenvolvida no âmbito da tese de doutoramento onde a presente comunicação se enquadra e que teve como objetivo desenvolver a 3.ª geração do PAS com enfoque na eficácia, fiabilidade, desempenho energético e gestão das lamas. A estratégia seguida consistiu em desenvolver ou selecionar a partirda 2.ª geração do sistema de avaliação, subconjuntos de indicadores e índices de acordo com os objetivos pré-estabelecidos, e desenvolver os valores de referência a partir de dados bibliográficos, equações empíricas e/ou estudos de campo. Na presente comunicação apresenta-se resumidamente a estratégia e a abordagem desenvolvida para cada objetivo de avaliação de desempenho.