This article is build on the experience of using Google Earth Engine as a development framework for a previous work by the same authors.Being primarily a distributed parallel computing platform, it is designed around a functional language pattern, even though supported on an object model, and a map / reduce distributed workload paradigm.Leveraging the sheer computing power delivered by the Google infrastructure and a multi petabyte remote sensing data repository, GoogleEarth Engine is an efficient development framework that presents itself in two basic flavors: one online integrated development environment which uses the browser Javascript engine; two APIs that can be deployed to a Python or a NodeJS environment.This work emphasizes the comparison between the Javascript browserbased implementation and the Python environment packages.

In contemporary construction practice, concrete surfaces are commonly coated; however, this factor is often disregarded in durability assessments, particularly with respect to carbonation. Such omission may lead to overly conservative designs and unnecessary material consumption. This study evaluates the actual performance of traditional coatings applied to concrete, considering three types of concrete: ordinary Portland cement (OPC), high-volume fly ash (FA), and high-volume FA with a low water-to-binder ratio. The coatings investigated were mainly based on cement and hydrated lime, with the inclusion of a FA-based alternative. Accelerated carbonation tests were performed on coated and uncoated concretes, as well as on coating mortars, while a sensitivity analysis was undertaken using an empirical and semi-probabilistic model across different exposure classes to simulate real service conditions. The results demonstrate excellent performance, with coated concretes achieving on average more than 52% higher resistance compared with uncoated counterparts. These findings indicate that properly designed coatings can enable reductions in cement content while still satisfying durability requirements, thereby contributing to more sustainable reinforced concrete structures.

No âmbito do projeto EROS - Erosão dos Litorais Rochosos – Diferenças Na Proteção Conferida Pelas Praias Arenosas e Pelas Formas Litorais, projeto PTDC/CTE-GIX/111230/2009 financiado pela Fundação para a Ciência e Tecnologia, efetuou-se a caraterização da agitação marítima na zona da praia da Galé, recorrendo ao modelo numérico SWAN (Booij et al. 1999). Esta caraterização é efetuada em duas partes: 1 – Aplicação e validação do modelo SWAN para as condições de agitação marítima que se verificaram no período 6 a 12 de Março 2012 que corresponde ao período em que se efetuaram medições in situ na praia da Galé; 2 – Aplicação do modelo SWAN para as condições de agitação marítima no período de 1998 a 2007 o que permite a caracterização do regime observado e médio da zona em estudo. O presente relatório descreve este trabalho. Assim depois desta introdução efectua-se no capítulo 2, a descrição do modelo SWAN, no capítulo 3 a aplicação e validação do modelo SWAN e a caracterização dos regimes observado e médio. O relatório termina com o capítulo de conclusões.

This article introduces the rationale behind the usage of the Google Earth Engine, and the advantages it offers, as an alternative to handle large volumes of georeferenced data using the existing tools we know as Geographic Information Systems on premises. Google Earth Engine is an efficient development framework that presents itself in two basic flavors: one online integrated development environment which uses the browser JavaScript’s engine; and two APIs that can be deployed on either a Python or a NodeJS environment. After presenting a limited number of use cases, representative of the Google Earth Engine design patterns, and building a prototype class using both variants, we conclude that both platforms are merely proxy APIs to the Google Earth Engine and do not have any measurable performance difference. However, since they run on fundamentally diverse contexts — a JavaScript’s engine on an internet browser, that integrates seamlessly with Google Maps, and a Python environment — it is argued that their utility depends on the user requirements instead of being true alternatives.

Cement production is responsible for approximately 7% of global carbon dioxide emissions. Despite our efforts, we have not been able to find a competitive substitute that is both reliable and environmentally friendly. The easiest way to solve the issue is to rationalize resources and try to minimize their use by replacing them with other materials. The current market shortage and reduced initial strength have limited the availability of blends that contain a significant amount of fly ash. Given the current economic, political, and environmental circumstances, it is predicted that a solution may be ternary blends with cement, fly ash, and MTK. Despite being “ancient” materials, there have been no recent global performance assessments. In this context, an investigation was carried out with ternary blend mortars. A significant volume of cement has been replaced with fly ash and metakaolin. The results show that these blends’ performance is promising because they offer a wide range of possibilities for replacing cement, maintaining or even improving its properties. MTK and fly ash’s synergies significantly enhance mechanical performance and durability. Furthermore, the global sustainability analysis shows that ternary blends are 36% more efficient than binary blends of cement and fly ash or metakaolin.

With the growing awareness of environmental problems, particularly with regard to energy efficiency and greenhouse gas emissions, the construction and the cement industry has had a prominent place, the latter being responsible for about 7% of CO2 emissions into the atmosphere. Knowing that cement production contributes about one tone of CO2 for every tone produced, it remains paradoxical that concrete, the product most consumed by humans, exceeded only by water, cannot find a credible replacement material for Portland cement, more efficient and greener. Considering the available technological solutions, involving energy efficiency of cement intensive production or the demand for alternative fuels for cement manufacture, a simpler solution might be the rationalization of resources by cement replacement by alternative materials. There is already a kind of concrete (high volume fly ash concrete) with very limited applications until nowadays but with intrinsically strong environmental advantages. However, the reduced early strength of this type of concrete is a limiting factor for his widespread usage. In this context, a study was developed in mortars with ternary mixtures where significant volumes of cement were replaced by fly ash, and also, simultaneously, for another addition functioning as a corrector of performance, the metakaolin. In this paper, one present the main advantages and drawbacks of the simultaneous use of these two mineral additions which synergy may cause very interesting performance characteristics even with high volumes of cement replacement. These ternary mixtures show very promising performances, allowing large volumes of cement replacement, maintaining or improving both mechanical and durability characteristics. These binders could be a viable solution for obtaining an eco-efficient enhanced performance concrete for widespread usage in construction as an alternative to conventional concrete.

O crescente volume de incorporação de cinzas volantes como substituição do cimento poderá ser um veículo para produzir um betão mais ecológico e eficiente. No entanto, a tecnologia atual não permite que este tipo de betão seja realmente eficaz, pois a sua resistência à carbonatação poderá ser menor. Além disso, a tendência demográfica para as populações aglomerarem-se em meios cada vez mais urbanos e industrializados, proporciona um ambiente cada vez mais agressivo e exigente para as estruturas de betão. Aborda-se uma metodologia para a mitigação deste problema, adicionando hidróxido de cálcio na composição do betão. Neste contexto desenvolveu-se uma campanha experimental em argamassas com o objetivo de caracterizar a resistência à compressão e à carbonatação. Os resultados sugerem que esta tecnologia pode ser aplicada no betão de modo vantajoso.

During wet curing, the alkali concrete compounds, such as calcium hydroxide, can be leached out to the curing solution, due to the pH gradient between concrete and curing solution. In the presence of high volume fly ash cementitious blends, there is a decrease in concrete pH that may further magnify the problem. In this context it was carried out a research in mortars with an original composition of high volume fly ash and calcium hydroxide. These were exposed to water curing and water saturated with calcium hydroxide curing. The results show that the introduction of calcium hydroxide in the curing solution, provides a slightly enhancement of carbonation resistance. Based on the obtained results, the incorporation of calcium hydroxide in the initial composition seems to be useful to develop extra strength to carbonation of high volume of fly ash concrete.

Com a consciencialização crescente dos problemas ambientais, nomeadamente no que concerne à eficiência energética e aos gases de efeito de estufa, a indústria da construção e do cimento tem tido um lugar de destaque, sendo esta última responsável por cerca de 7% das emissões de CO2 para a atmosfera. Sabendo que a produção de cimento contribui com cerca de uma tonelada de CO2 por cada tonelada produzida, não deixa de ser paradoxal que o produto mais consumido pelo Homem, apenas ultrapassado pela água, não encontre um substituto credível, mais eficiente e mais ecológico. Considerando as soluções tecnológicas disponíveis, envolvendo a eficiência energética da produção, a produção intensiva ou a procura de combustíveis alternativos para o fabrico de cimento, uma solução mais simples poderá estar na racionalização dos recursos e na sua substituição por materiais alternativos. Já existe um tipo de betão (betão de elevado volume de cinzas volantes) com aplicações ainda muito restritas, mas com grandes vantagens ambientais. No entanto, as reduzidas resistências iniciais são uma das características limitativas da sua utilização. Neste contexto, foi desenvolvido um estudo experimental com misturas ternárias onde volumes significativos de cimento foram substituídos por cinzas volantes, e, também, em simultâneo, por uma outra adição, o metacaulino, funcionando esta como um factor corrector do desempenho. Neste trabalho, apresentam-se as principais vantagens e inconvenientes da utilização simultânea de duas adições, cinzas volantes e metacaulino, que poderão originar características de desempenho muito interessantes mesmo com elevados volumes de substituição. As sinergias resultantes destas misturas ternárias demonstram desempenhos muito promissores, possibilitando grandes volumes de substituição do cimento, mantendo ou melhorando os desempenhos mecânicos e de durabilidade, podendo vir a ser uma solução viável para a obtenção de um betão eco-eficiente de desempenho melhorado para uso generalizado na construção como alternativa ao betão convencional.

Phenolphthalein is the most common pH indicator used to measure the carbonation depth of cementitious materials. It is simple and quick to use, but according to some authors, is not an appropriate tool. Moreover, this substance is in the candidate list as a substance of very high concern by European Chemicals Agency. This article discusses the use of thymolphthalein rather than phenolphthalein. Accelerated carbonation tests were performed on cement mortars and high volume fly ash mortars. Once this kind of mixtures has low carbonation resistance additional alkalinity was provided by adding hydrated lime during its fresh mixture, and by curing the samples immersed in a calcium hydroxide solution. The results showed that the best indicator was the thymolphthalein, mainly for blends with lower carbonation depth. It was also checked that adding alkalinity can be useful for increasing the carbonation resistance.