Artigos de Revista

Arundo donax (giant reed or giant cane) is a widely available, perennial, invasive, non-food crop, present worldwide and employed for several uses, including building practices. Considering the increasing demand for sustainable building materials, A. donax can be an eficient solution. This study investigated its properties as a bio-aggregate mixed with a sodium silicate solution as an adhesive. A horizontal analysis that provided a general characterization of the composite was carried out. The results showed that the A. donax-based composite had anapparent density of 517 kg/m3 , thermal conductivity of 0.128 W/(m.K), and high hygroscopicity, with a moisture buffering value of 4.33 g/(m2 %RH), property that could be both an advantage for indoor comfort and a drawback. The uncommon sound absorption behaviour can be comparable to granular materials, with the highest sound absorption coeficient values,

Arundo donax (giant reed or giant cane) is a widely available, perennial, invasive, non-food crop, present worldwide and employed for several uses, including building practices. Considering the increasing demand for sustainable building materials, A. donax can be an efficient solution. This study investigated its properties as a bio-aggregate mixed with a sodium silicate solution as an adhesive. A horizontal analysis that provided a general characterization of the composite was carried out. The results showed that the A. donax-based composite had an apparent density of 517 kg/m3, thermal conductivity of 0.128 W/(m.K), and high hygroscopicity, with a moisture buffering value of 4.33 g/(m2 %RH), property that could be both an advantage for indoor comfort and a drawback. The uncommon sound absorption behaviour can be comparable to granular materials, with the highest sound absorption coefficient values,

The popularity of natural cement (Roman cement) in buildings from the late 19th and thebeginning of the 20th century and the high diversity of characteristics of natural cement demandresearch of mortar and binders used in the buildings of this period in Portugal. Understandingthe type of binder used in the historic buildings will help the project/intervention team to makethe best decisions in terms of the development of compatible mortars for historical conservationpurposes. Casa Barbot is one of the Art Nouveau examples of the beginning of the 20th century inPortugal. The garden of this building is characterized by peculiar elements in terms of materials andarchitecture. Full characterization of the mortars employed in the construction of this building as wellas identification of the used binder is the main objective of this study. The study comprises a widerange of laboratory characterization techniques such as X-ray fluorescence (XRF), X-ray diffraction(XRD), petrography, open porosity, density, water absorption by capillarity, and compressive strength.The results show the diversity of compositional characteristics in the mortars used in the decorativeelements in the period garden of Casa Barbot. All mortars are composed of Portland cement with amix of additives such as blast furnace slag, limestone filler, air lime, and the occasional presence ofcharcoal. The results raise doubt about the use of natural cement as stated in the historical documents.This study will broaden the scientific knowledge of the materials of that period in Portugal to providea comprehensive plan for the preservation of historical buildings.

This paper reports on the study of renders and plasters from 20th-century award-winning buildings in Lisbon (Portugal) with the Valmor Prize for Architecture. The mortars have been investigated through XRD, optical and electronic microscopy (SEM-EDS), thermal analysis (TGA/DTA), wet chemical analyses and AAS. The results reveal that the use of air lime lasted until the 1940s. It also highlights the beginning of using of Portland cement in mortars in the 1930s, mixed with airlime, and the abandonment of mortar formulations solely based on air lime. This study highlights the use of finishing lime-gypsum-based mortars until the 1940s and different types of Portland cement from the 1940s onwards. Portland cement was the main binder for the analysed stoneimitating mortars from 1940s to 1970s. Finally, salt contamination was occasionally found in mortars, which generally reveal a good state of conservation

Beaches combined with sloping structures are frequently the frst element of defense to protect urban areas from the impact of extreme coastal fooding events. However, these structures are rarely designed for null wave overtopping discharges, accepting that waves can pass above the crest and threat exposed elements in hinterland areas, such as pedestrians, urban elements and buildings, and vehicles. To reduce risks, Early Warning Systems (EWSs) can be used to anticipate and minimize the impacts of fooding episodes on those elements. A key aspect of these systems is the defnition of non-admissible discharge levels that trigger signifcant impacts. However, large discrepancies in defning these discharge levels and the associated impacts are found among the existing methods to assess foodings. Due to the lack of standardization, a new conceptual and quantitative four-level (from no-impact to high-impact) categorization of food warnings (EW-Coast) is proposed. EW-Coast integrates and unifes previous methods and builds on them by incorporating feld-based information. Thus, the new categorization successfully predicted the impact level on 70%, 82%, and 85% of the overtopping episodes afecting pedestrians, urban elements and buildings, and vehicles, respectively. This demonstrates its suitability to support EWSs in areas vulnerable to wave-induced fooding.

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No presente artigo abordam-se, sumariamente, algumas matérias ligadas à habitação dirigida para idosos e fragilizados, promovida correntemente por cooperativas de habitação, ou no âmbito dos atuais processos propostos de

During physical scale model tests of rubble mound breakwaters, the assessment of the eroded volume of the armour layer subjected to incident sea waves can be determined from consecutive surveys of the surface of the armour layer after each test run. This enables one to assess the damage level of the struc ture by comparing erosion profiles and by the eroded volume between consecutive surveys of the tested section. The present study aimed to evaluate the damage evolu tion of a section of the Peniche harbour west breakwater, whose armour layer is made of tetrapods, A dimensionless damage parameter was computed, based on the eroded volume at the end of each test. The test program consisted of three test series (A, B and C) with different durations and wave conditions sequences, considering the low-water level (water depth of 0.20 m at the toe of the structure) and high-water level (0.24 m) and sea states with peak periods Tp = 1.70 s and Tp = 1.98 s and significant wave heights, Hm0, ranging between 0.12 m and 0.19 m. The model was built and operated according to Froude

Melby presents a formula to predict damage evolution in rubble-mound breakwaterswhose armour layer is made of rock, based on the erosion measured in scale-model tests and thecharacteristics of the incident sea waves in such tests. However, this formula is only valid for armourlayers made of rock and for the range of tested sea states. The present work aims to show howthe Melby methodology can be used to establish a similar formula for the armour layer damageevolution in a rubble-mound breakwater where tetrapods are employed. For that, a long-durationtest series is conducted with a 1:50 scale model of the quay section of the Ericeira Harbour breakwater.The eroded volume of the armour layer was measured using a Kinect position sensor. The damageparameter values measured in the experiments are lower than those predicted by the formulationfor rock armour layers. New ap and b coefficients for the Melby formula for the tested armour layerwere established based on the minimum root mean square error between the measured and thepredicted damage. This work shows also that it is possible to assess the damage evolution in scale model tests with rubble-mound breakwaters by computing the eroded volume and subsequently, thedimensionless damage parameter based on the equivalent removed armour units.

Buildings are subjected to deformations of their reinforced concrete structure due to vertical loadsthat can lead, in certain cases, to the significant cracking of the unreinforced masonry (URM) infill walls,therefore requiring the development of specific knowledge of these types of deformations in order to minimisethem.Aiming the evaluation of buildings with reinforced concrete structures subjected to vertical deformations, themechanical characteristics of their infill masonry walls, as well as of their interface with the supportingconcrete elements, are here analysed. The basic compression behaviour of brick masonry is assessedparticularly through the previous analysis of a vertical compression test of a masonry specimen. Themechanical behaviour characteristics of the constituents (bricks, and mortar joints) are analysed to account fortheir influence on the compression behaviour of masonry infill, aiming particularly for the prevision of theircracking in case of vertical deformations of the supporting reinforced concrete (RC) elements. Based on thatevaluation, the analysis of masonry walls subjected to vertical deformations of their supports is made throughthe assessment of the relevant characteristic behaviour of masonry wall-beam/slab assembly in case of verticalload. A general modelling approach of the behaviour of URM infills and the interaction with their supports isgenerally accessed. Finally, the preventive control of deformations of masonry wall-beam/slab assembly isdiscussed.