Artigos de Revista

Alkali-silica reaction (ASR) is a type of deterioration that has been causing serious expansion, cracking and durability/operational issues in concrete structures worldwide. The presence of sufficient moisture, high alkali content in the cement paste and reactive forms of silica in the aggregates are the required conditions for this reaction to occur. Reactive aggregates of volcanic nature have been reported in different countries such as Japan, Iceland and Turkey, among others. The presence of silica minerals and SiO2-rich volcanic glass is regarded as the main cause for the reactivity of volcanic rocks. In Portugal, volcanic aggregates are mainly present in Azores and Madeira Archipelagos and, for several years, there was no information regarding the potential alkali-reactivity of these rocks. Since the beginning of this decade some data was obtained by the work of Medeiros (2011) and Ramos (2013) and by the national research projects ReAVA, (Characterization of potential reactivity of the volcanic aggregates from the Azores Archipelago: implications on the durability of concrete structures) and IMPROVE (Improvement of performance of aggregates in the inhibition of alkali-aggregate reactions in concrete), respectively. In order to investigate the potential alkali-reactivity of aggregates from both archipelagos, a total of sixteen aggregates were examined under the optical microscope and, some of them, also under the Scanning Electron Microscope with Energy Dispersive X-ray Spectroscopy. A set of geochemical analyses and laboratory expansion tests were also performed on those volcanic aggregates. The main results showed that the presence of volcanic glass is rare in both archipelagos and that the samples of Madeira Archipelago contain clay minerals (mainly from scoria/tuff formations inter-layered with the lava flows), which can play a role in concrete expansion. The results of the laboratory tests showed that one of the samples performed as potentially reactive in the accelerated mortar-bar test (ASTM C 1260) and that the majority of the Azores samples started to show some expansion just after one year of testing in the concrete prism test (CPT) at 38ºC.

This paper presents the analysis of the probability of occurrence of wave overtopping events as well as its consequences at the Port of Las Nieves in Agaete, Gran Canaria Island, with the evaluation of the resulting level of flood risk. The study has been conducted using a third-generation spectral wave model to reproduce wave propagation from deep to shallow water depths considering the associated mean sea level, and a neural network-based model, for estimating mean wave overtopping discharges. Results reveal that overtopping in the initial sections of the port, located in the port access area, is substantially higher than that associated with the cross-sections of the main body of the breakwater, so that control actions to reduce overtopping are required due to the important socioeconomic implications regarding the infrastructure inoperability.

Kosovo is relatively small place with 10870 km2 where 44.7% of its territory is covered with trees. To date, Kosovo has passed through three important phases of economic development; the first phase was the emergency one after war, the second phase was privatization of social enterprises and the third phase was sustainable development. The after war period was very important for this sector because it has passed through a reconstruction process, privatization and development and become part of the internal and foreign markets. Positive developments in the field of wood industry led to the number of work places offered in this field are increasing; also requirements for specialized workforce and qualification workers are increasing. This is the reason why today

Apresenta-se o Projeto CyberParks para discutir a relação entre o uso de meios digitais (smartphones, conexões wi-fi etc.) em espaços públicos (parques, jardins, praças etc.) e a contribuição das novas tecnologias para qualificar e aumentar a participação de usuários na sua produção e manutenção. CyberParks é guiado pelas questões: (1) Como as Tecnologias de Informação e Comunicação (TIC) afetam o uso do espaço público? (2) Quais são os riscos associados à recente, mas acelerada, dinâmica de difusão das TIC no espaço urbano? (3) Como os usos identificados se enquadram no conceito de sociedade virtual? Em suma, trata-se deinvestigar a contribuição das TIC na transformação das cidades em contextos mais inclusivos, e não somente mais high tech. O projeto objetiva desvendar o papel das TIC na produção e no desenho de espaços híbridos. Uma premissa é aumentar o conhecimento das possibilidades que as TIC abrem para uma melhor compreensãoda forma como as pessoas usam esses espaços. Discutem-se o âmbito e a pertinência da perspectiva de estudo focada na relação entre TIC e espaço público, apresentando objetivos do Projeto CyberParks. Em sequência, problematizam-se algumas das principais linhas de investigação, apresentando os resultados de um estudo de caso desenvolvido em Lisboa, Portugal.

High quality services of wastewater treatment require a continuous assessment and improvement of the technical, environmental and economic performance. This paper demonstrates a comprehensive approach for benchmarking wastewater treatment plants (WWTPs), using performance indicators (PIs) and indices (PXs), in a

The aim of this paper is to present a comprehensive approach for spatial and temporal demand profiling in water distribution systems. Multiple linear regression models for estimating network design parameters and decision trees for predicting daily demand patterns are presented. Proposed approach is a four-step procedure: data collection, data processing, data characterization, and spatial and temporal demand profiling. Continuous flow measurements and infrastructure and billing data were collected from a large set of water network areas and combined with census data. Main results indicate that family structures (i.e., families with elderly or adolescents), individuals

Railway infrastructure managers can benefit from more advanced tools to analyse available data in asset management activities. In this work, the authors present a contribution to anticipating the development of critical locations in railway tracks, such as transition zones and other singularities, using a novel method to analyse railway track performance. Information on track geometry records, namely the evolution on the longitudinal level of a case study, is integrated with information from a numerical study on the effect of track irregularities on the train-track system and with characteristics of the track superstructure and substructure. The approach involves analysing the information in terms of the length of the defects and respective amplitudes to identify locations suggesting: higher derailment risk, faster track degradation and lower passenger comfort. The application of this method suggested that track singularities and changes in the substructure seem to trigger rapid track degradation. The consideration of shorter moving windows in the analysis of the standard deviation of the longitudinal level showed to be a promising approach to assess the degradation rates at track singularities. The proposed method, in association with other tools can provide crucial information for railway infrastructure managers.

New challenges in flood risk management are raised by climate change and land-use development. These challenges are particularly complex in estuarine and coastal systems, where different hazard sources interact in a dynamic socioeconomic context. This paper presents an innovative approach to support flood risk management in estuaries. The approach, developed at a local-scale basis, is applied in the case study of the Tagus estuary (Portugal). The methodology is supported by the regional framing of the study area and integrates hazard, exposed elements, territorial vulnerability and risk assessments considering different climate scenarios. Through the involvement of the various risk management dimensions, the results allow the definition of a new decision-making supporting framework for emergency and land-use planning. At the emergency level, the results include a WebGIS interface providing an early-warning system for the locations with highest risk of flooding and the definition of emergency planning guidelines. A set of flood adaptation actions based on land-use and occupation measures are recommend to increase resilience in face of flooding and future sea-level rise. The institutional capacity-building is achieved through the availability of information and tools that can effectively support decision-making. Additionally, the outcomes contribute to better understand flood risk in estuaries and to strengthen its prevention, preparedness and response, priorities defined in the Sendai Framework for Disaster Risk Reduction 2015-2030.

Drilling resistance measurements made on soft mortars or other soft and very heterogeneous materials are difficult to interpret due to the extreme irregularity of values caused by the high contrast of strength between the binding matrix and the hard aggregates. Direct comparison of drilling graphs is usually difficult and even impossible. To overcome this difficulty, a methodology was developed using an algorithm to identify the values characteristic of the binding matrix, avoiding the interference of the aggregates. The methodology consists in sorting data at defined depth segments and, for each segment, taking the average of a given percentile of the lowest values. When the consolidation action of any treatment on a soft mortar is sought, the comparison of the averaged values for homologous segments before and after treatment gives a direct value for this consolidation. The methodology was tested with a soft 2-layer lime mortar treated with nanolime. Drilling data for consecutive segments of 2 and 5 mm in depth were used to show how the methodology works. The consolidation action was clearly depicted and the hidden layer could also be identified and characterized. The methodology is simple to operate using a spreadsheet file.

Many national and regional administrations are currently facing challenges to ensure long-term sustainability of urban water services, as infrastructures continue to accumulate alarming levels of deferred maintenance and rehabilitation. The infrastructure value index (IVI) has proven to be an effective tool to support long-term planning, in particular by facilitating the ability to communicate and to create awareness. It is given by the ratio between current value of an infrastructure and its replacement cost. Current value is commonly estimated according to an asset-oriented approach, which is based on the concept of useful life of individual components. The standard values assumed for the useful lives can vary significantly, which leads to valuations that are just as different. Furthermore, with water companies increasingly focused on the customer, effective service-centric asset management is essential now more than ever. This paper shows results of on-going research work, which aims to explore a service-oriented approach for assessing the IVI. The paper presents the fundamentals underlying this approach, discusses and compares results obtained from both perspectives and points to challenges that still need to be addressed.