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Biomass fly ash has been studied has a partial cement material, since this material has a positive effect on concrete properties. Even though, some mixes with BFA presents a positive benefit, they need to be economically competitive and present a good environmental performance. So, the analyse and comparison of concrete that uses BFA as raw material substitution in terms of environmental impacts related to the production of conventional concrete. One of the best approaches to develop this type of study is to use the life cycle assessment (LCA) method. This method quantifies both the input flows, such as energy, water and materials, as well as the output flows, such as CO2 emission, solid wastes and liquid wastes. Based both on the abovementioned context and methodological approach, a quantification and comparison of potential environmental impacts resulting from the production of 1 m3 of concrete was made, using different types of binder and quantities of cement substitution., The authors wish to thank the Portuguese Foundation for Science and Technology (FCT) and the Eco-Construction and Rehabilitation Doctoral Program for supporting the PhD scholarship (reference PD/BD/ 52661/2014). This work was partly financed by FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020.

Sustainable construction is high on the agenda, especially regarding building materials. Using of by-products or waste materials from other economic sectors as cement replacement material in concrete production seems to be a more sustainable option than applying ordinary Portland cement concrete. The main aim of this work was to evaluate the performance of biomass fly ash (BFA) when used as cement replacement material and as an alkalinity reserve material in high-volume fly ash concrete (HVFAC). Therefore, several compositions of concrete including BFA were tested for compressive strength, water absorption, accelerated carbonation, and chloride penetration resistance. It was noted that when small amounts of BFA were used, HVFAC properties were improved, compared with a high-volume coal fly ash concrete. These new concrete mixtures showed a positive contribution to the quality, durability and sustainability of HVFAC., The authors wish to thank the Portuguese Foundation for Science and Technology (FCT) and the Eco-Construction and Rehabilitation Doctoral Program for supporting the PhD scholarship (reference PD/BD/ 52661/2014). This work was partly financed by FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/ 04029/2020.

A redução do consumo do cimento através da sua substituição parcial por resíduos industriais com características pozolânicas tem sido uma estratégia com eleva aceitação. O potencial de utilização do pó de vidro (PV) como substituto parcial do cimento tem sido investigado. Sendo um material com elevado teor de sílica, o vidro moído, numa finura adequada, pode apresentar uma atividade pozolânica significativa. Neste sentido, desenvolveu-se um trabalho experimental considerando o impacto de diferentes finuras do PV e diferentes percentagens de substituição, na resistência mecânica de argamassas. Foram moldados provetes de referência e com PV. A relação água/ligante das argamassas foi mantida em 0,5 e foram consideradas 4 percentagens de substituição: 5, 15, 25 e 35%. Para cada percentagem, foram moldados provetes com 2 diferentes finuras de PV. Os provetes foram curados durante 7 e 28 dias e, em seguida, foram ensaiados à compressão. Os resultados obtidos sugerem um desempenho mecânico satisfatório das argamassas com PV (15 e 25%) face às de referência. Para as condições estudadas, quanto mais fino o PV, mais evidente é este comportamento. O que sugere que o PV tem potencial para ser utilizado na produção de betão como substituto parcial do cimento, proporcionado ganhos económicos e ambientais., Reducing cement consumption through its partial replacement by industrial waste with pozzolanic characteristics has been a strategy with high acceptance. The use of glass powder (GP) as a partial replacement for cement has been investigated. Since the glass has a high silica content, ground glass, at an appropriate fineness, can have significant pozzolanic activity. Experimental work was developed considering the impact of different GP fineness and different replacement percentages on the mechanical strength of mortars. Reference and GP specimens were molded. The water/binder ratio of the mortars was kept at 0.5 and 4 replacement percentages were considered: 5, 15, 25 and 35%. For each percentage, specimens were molded with 2 different GP fineness. The specimens were cured for 7 and 28 days and then were tested in compression. The results show a satisfactory mechanical performance of mortars with GP (15 and 25%) compared to the reference. For the conditions studied, the thinner the GP, the more evident this behaviour is. Thus, the GP has the potential to be used in the production of cementitious materials as a partial substitute for cement, providing economic and environmental gains., Este trabalho foi financiado por Fundos Nacionais através da FCT/MCTES – Fundação para a Ciência e Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior, no âmbito do CTAC – Centro de Território, Ambiente e Construção – UIDB/0407/2020 e UIDP/04047/2020, e no âmbito do projeto com a referência 2000.03197.PTDC, GlassCON.

A indústria cimenteira destaca-se como sendo o segundo maior emissor industrial de dióxido de carbono (CO2). Neste sentido, a redução do uso do cimento no betão, sem prejuízo dos avanços técnicos já adquiridos, é uma tendência mundial. A substituição parcial do cimento por cinzas volantes (CV) no betão tem sido utilizada com vantagens ao nível técnico, económico e ambiental. Os betões com CV destacam-se pela elevada resistência ao ataque por cloretos (Cl-), sendo menos resistentes à carbonatação. Este trabalho experimental tem como objetivo avaliar o comportamento dos betões com CV face à carbonatação, em ambientes marinhos. Assim, foram moldados provetes de argamassa e betão com 0 e 40% de substituição de cimento por CV. Para tal, foram utilizados ensaios acelerados para contaminação dos provetes por Cl- e CO2. Os resultados apontam para uma redução da profundidade de carbonatação dos provetes sujeitos ao contato com os Cl- e CO2 quando comparados aos provetes sujeitos apenas ao CO2, independentemente do percentual de CV. Considerando a menor resistência do betão com CV face à carbonatação, esta redução na profundidade de carbonatação aponta para uma dimensão positiva relacionada ao seu uso. Aspetos relacionados à porosidade do betão e ao efeito higroscópico do cloreto de sódio (NaCl), podem estar na origem deste comportamento., The cement industry is the second largest industrial emitter of (carbon dioxide) CO2. Reducing the use of cement in concrete, and maintaining its technical qualities is a worldwide trend. The partial replacement of cement by fly ash (FA) in concrete has been used with technical, economical, and environmental advantages. Concretes with FA have greater chloride (Cl- ) attack resistance, but the carbonation resistance is lower. This experimental research aims to evaluate the behaviour of concretes with FA in relation to carbonation, in marine environments. Specimens were moulded with 0 and 40% replacement of cement by FA. Accelerated tests were used to contaminate the specimens with Cl- and CO2. According to the obtained results, there is a reduction in carbonation depth in the specimens submitted to Cl- and CO2 when compared to those submitted only to CO2, regardless of the percentage of FA. Considering the limited resistance of concrete with FA related to carbonation, this reduction in carbonation depth is a positive aspect. The porosity of concrete and the hygroscopic effect of sodium chloride (NaCl) may be at the origin of this behaviour., Este trabalho foi financiado por Fundos Nacionais através da FCT/MCTES – Fundação para a Ciência e Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior, no âmbito do CTAC – Centro de Território, Ambiente e Construção – UIDB/0407/2020 e UIDP/04047/2020.

A sustentabilidade é um problema atual e preocupa a população global em geral. A utilização do cimento Portland é um dos principais responsáveis pela emissão de gases de efeito de estufa associados à indústria da construção, obrigando à procura de materiais alternativos. Neste contexto, as misturas ativadas alcalinamente (MAA), dispensando o uso de cimento, são uma alternativa inovadora e promissora aos materiais cimentícios tradicionais. A ocorrência de incêndios em edifícios mostra que são necessárias estruturas com resistência térmica acrescida, melhor que a conseguida com materiais cimentícios. Assim, procurou-se desenvolver uma MAA otimizada, que permita uma solução viável ao fogo, com um desempenho superior ao dos materiais cimentícios comuns. O dimensionamento da MAA ótima resultou da aplicação da metodologia da superfície de resposta (MSR). Os principais fatores no dimensionamento deste tipo de composições foram as razões molares dos seus constituintes e a razão água/ligante (A/L). As razões molares foram fixas de acordo com os precursores e ativadores utilizados e A/L foi considerada com o valor 0,3. As MAA otimizadas obtiveram valores de resistência mecânica à compressão na ordem dos 45 MPa e um desempenho superior ao fogo, quando comparadas com as misturas de controlo, produzidas com cimento Portland. Com base no trabalho desenvolvido, de modo a obter construções mais eficientes sob ação de temperaturas elevadas, as MAA demonstraram grande potencial de utilização., Sustainability is an issue nowadays and concerns the global population in general. The use of Portland cement is one of the main responsible for the emission of greenhouse gases associated with the construction industry, demanding in the search for alternative materials. In this context, alkaline activated mixtures (AAM), made without cement, are an innovative and promising alternative to cementitious traditional materials. The occurrence of fires in buildings shows that structures with enhanced thermal resistance are necessary, better than the one obtained with cementitious materials. Thus, it was developed an optimized MAA, which allows a viable solution to fire, with a performance superior to that of common cementitious materials. The design of the optimal AAM resulted from the application of the response surface methodology (RSM). The main factors in the design of this type of compositions were the molar ratios of their constituents and the water/binder ratio (W/B). The molar ratios were fixed according to the precursors and activators used and for W/B was adopted the value 0,3. The optimized AAM obtained mechanical compressive strength values in the range of 45 MPa and enhanced fire performance when compared to the control mixtures, made with Portland cement. Based on the work developed, in order to obtain more efficient constructions under the action of high temperatures, the use of AAM showed great potential., Este trabalho foi financiado por Fundos Nacionais através da FCT/MCTES – Fundação para a Ciência e Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior, no âmbito do CTAC – Centro de Território, Ambiente e Construção – UIDB/0407/2020.

Microbial induced calcium carbonate (CaCO3) precipitation (MICCP) is a promising technique for the production of building materials with lower environmental impact than traditional building materials. Sand cementation through microbial activity is a process that uses a microbial agent and nutritive medium as a source of calcium that enables the production of CaCO3, which is used as an agglomerating factor for sand grains forming biosandstones. The present study proposes the formation of biosandstones using a filamentous fungus, Penicillium brevicompactum, as a microbial agent to carry out this process and to analyze the effect of calcium concentration in the nutrient media on the compressive strength and density. Biosandstones samples were produced using a P. brevicompactum spores suspension, manually mixed with sand and nutrient medium with four concentrations of 20, 40, 60 and 80 mM of calcium lactate (C6H10CaO6). The mixtures were placed in cylindrical molds with a diameter of 50 mm and height of 100 mm and six samples were produced for each experimental condition. The samples were weighed and measured to determine their densities and submitted to an unconfined compressive strength test after a 14-day treatment period. All medium used enabled the formation of biosandstones. Compressive strengths average showed values between 26 kPa to 325 kPa with a maximum coefficient of variation of 12% and densities ranged from 1.43 g/cm3 to 1.65 g/cm3 and a maximum coefficient of variation of 1.8%. The increase in calcium concentration enabled the production of sandstones with greater compressive strength and as expected, density. Nonetheless, the compressive strength results of the samples produced using the media with a concentration of 60mM and 80 mM did not show statistically significant differences, as the density of the samples that used medium with a concentration of 80 mM were higher than those produced with a concentration of 60 mM of C6H10CaO6. Thus, it can be demanded that the increased availability of calcium in nutrient medium enabled greater bioprecipitation of CaCO3 by the action of P. brevicompactum. Results showed the viability of using fungi for the production of building materials with lower environmental impacts than those used currently., info:eu-repo/semantics/publishedVersion

The construction industry, one of the most worldwide important productive and economic activity, is also responsible for environmental impacts like the extraction of raw materials, generation of waste, and cement manufacturing. The main objective of the present work was to study the technical feasibility of applying the residue generated by the second-generation ethanol obtained from sugarcane to partially replace the cement in cementitious mixtures. Characterized as a high lignin residue, it contains a high amount of silica in a weakly polymerized organic structure, and its ashes are a very reactive pozzolanic material. The research sought to obtain answers regarding the performance of the cementitious compositions in the fresh state and in the hardened state. Then, the possible behavior differences between the residue with and without the presence of chemical admixtures were compared. The results showed that there was compatibility between the residue and the selected chemical admixtures; the setting time and the consistency index increased with the presence of the residue; the compressive strength with the residue was lower than the reference composition, but it still demonstrated feasibility; and in some tests carried out, the durability indicators improved in the residue compositions. Thus, the results were very promising and pointed to major developments.

Hoje em dia, diversos subprodutos ou resíduos têm sido estudados para a sua incorporação nos materiais de construção e um desses subprodutos são as cinzas volantes de carvão (CV). No entanto, o uso de grandes volumes desses materiais apresenta algumas dificuldades para as características dos betões, sendo uma delas, a sua suscetibilidade aos problemas associados com a carbonatação. Assim, é necessário encontrar novos materiais ou soluções para estes problemas. Cinzas volantes de biomassa (CB) são um resíduo com origem na queima de biomassa florestal para a produção de calor e energia, em países como Portugal, este subproduto é depositado em aterros. Uma vez que, este resíduo apresenta características pozolânicas, muitos estudos têm tentado perceber se é possível a sua aplicabilidade como material substituto do cimento na produção de betão. Neste estudo, o efeito do uso de CB na qualidade, durabilidade e sustentabilidade de betões foi avaliado. Uso de grandes quantidades de CB não conduz à produção de betões com melhor desempenho do que betões convencionais (só com cimento como ligante). Contudo, o uso de pequenas quantidades de CB misturadas com cinzas volantes de carvão, permite obter resistências à compressão similares às das composições produzidas só com cimento, mas melhorando a resistência à carbonatação e à penetração de cloretos e majorando o desempenho ambiental. Os resultados mostraram que, uma das soluções para a minimização de problemas relacionados com betões com elevados teores de cinzas volantes, pode ser a utilização de pequenas quantidades de CB misturadas com CV. Uma vez que, o uso de pequenas quantidades de CB misturado com CV conduz a betões com qualidade similar, mas com uma maior durabilidade e sustentabilidade do que betões só com cimento como ligante e que minimiza o efeito da dosagem de grandes quantidades de CV., Os autores querem agradecer à Fundação para a Ciência e Tecnologia (FCT) e ao Programa de Doutoramento em Eco-Construção e Reabilitação pelo apoio à bolsa de doutoramento (referência PD/BD/52661/2014). Este trabalho foi parcialmente financiado pela FCT/MCTES através de fundos nacionais (PIDDAC) no âmbito da Unidade de I&D Instituto para a Sustentabilidade e Inovação em Engenharia de Estruturas (ISISE), sob a referência UIDB/04029/2020.

Over the last decade, microbial induced calcium carbonate precipitation (MICCP) has been used in several types of research due to its potential in applications for the areas of construction materials and geotechnics. Biotechnology into the area of building materials, has enabled the development of the so-called biomaterials of construction produced through biomineralization. Most of the biocementation studies to make biosandstones, biobricks or to promote bio self-healing on concrete present bacteria as the microorganisms responsible for the CaCO3 induction process. Fungi are potentially better for the biocementation process because they have more biomass and some develop filaments that can be used as microfibers on materials. Thus, the present work proposes the development of a methodology to analyse the potential use of two urease-positive fungi (Penicillium chrysogenum MUM 9743 and Neurospora crassa MUM 9208) to produce biosandstone. The microstructure and chemical constituents of biocrystals formed due to MICCP were observed under Scanning Electron Microscopy (SEM). SEM showed fungal mycelia as bio-based fibre in biosandstone and clusters of probable calcite crystals on and around mycelia. Despite the resistance obtained was up to 50-66 kPa until now, both fungi were able to promote biocementation of sand. More research is needed to increase the material resistance up to 1-2 MPa that is required for these building materials., This study was supported by the Portuguese Foundation for Science and Technology (FCT) underthe scope ofthe strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE‐01‐0145‐FEDER‐000004) funded by the European Regional Development Fund under the scope of Norte2020 ‐ Programa Operacional Regional do Norte., info:eu-repo/semantics/publishedVersion

Carbonation is one of the factors that can influence the chlorides transport. Despite the combined action of chlorides and carbonation being a reality, there is no consensus on the effect of this coupled deterioration on chloride transport. Accelerated tests were used to simulate this environment. Concrete specimens were cast using 0.60 water/cement ratio and CEM I 42.5R. After curing, half of specimens was submitted to accelerated carbonation test (20ºC, 55% RH and 4% CO2) during 1 and 7 months. The other half was protected with plastic film during the same period. Then, the specimens were submitted to the accelerated chlorides attack using: migration test and immersion test. Finished the immersion test, powder samples were extracted from surface to bulk and analysed to obtain free and total chloride profiles and pH profile. According to migration test results, the carbonation increases chloride transport regardless the test period. According to the immersion test results, there is a decrease in chloride ions transport when the specimens are carbonated for 1 month and a noticeable increase when carbonation period increases to 7 months. The redistribution of pores in carbonated concrete and the difficulty of chlorides binding in carbonated concrete are related to these results., (undefined)

This work has as main objective the evaluation of the effect of the content of hybrid fibers on the flexural strength, toughness and residual resistances of reinforced concrete with hybrid fibers (RFC) of steel and carbon nanotubes (CNT). Three different quantity of CNT were previously dispersed by ultrasonication using a Pluronic F-127 surfactant concentration. A fixed quantity of steel fibers was used in concrete. The results obtained shows improvement in mechanical properties of RFC as compressive strength, flexural strength, flexural modulus, good interaction between steel fibres and CNTs, in the microstructure of concrete matrix and in the Pull Out steel fibre strength. The concrete showed a ductile behaviour improved with the hybridization when compared just with steel fibres. This high performance material can be applied in specific buildings like defense engineering with sensing properties.

During the 21st century, within road infrastructure management there is a strong enforcement on preserving assets and prevent roadway collapses. As a result, public agencies have to implement periodic inspections and asset condition assessments. As pavements and bridges also culverts management play a special role in roadway safety, because they prevent roadbed erosion. The scope of this investigation is the assessment and forecast of culverts performance regarding rating condition and network reliability forecast. In addition, it intends to analyze hazards influence in the culvert serviceability, modelling the hazards actions on the infrastructure. In this paper, is performed the literature review of studies done during the past decade comparing advantages and limitations. Five main subjects are identified in the development of a culvert management system, since the inventory and inspection framework, to forecasting models and risk assessment. Moreover, it will determine the correlation between subjects and will find gaps for improvement., (undefined)

The thermal modification has proved to be an effective method to improve the durability of wood elements. Until now, most applications of thermally modified wood have been limited to non-structural applications since the wood’s heat treatment leads to a significant reduction in mechanical performances. However, there is no knowledge about these treatments applied on the wood species more used in Portuguese constructions. In order to evaluate the effect of heat treatment on the wood species of Maritime pine (Pinus pinaster), Eucalyptus (Eucalyptus globulus), Beech (Fagus sylvatica), Acacia (Acacia melanoxylon) and Oak (Quercus faginea), an experimental program consisted of mechanical bending tests and dimensional stability tests (shrinkage, swelling and equilibrium moisture content) was defined. For comparison purposes, all tests were made with test specimens of non-modified and thermally modified wood using four temperature values (200ºC, 240ºC, 260ºC and 300ºC) and three exposed periods (2, 4 and 8 hours). The obtained results show that the behaviour of the studied experimented species was similar to the one of other species already studied in the available literature. It was possible to point out that mechanical properties decrease with the severity of the thermal treatment, while the dimensional stability improved.