Artigos de Revista

In order to contribute to the knowledge about the influence of several factors on the in-service performance of renders, as well as about the applicability of in-situ testing techniques in the evaluation of their performance, an experimental work was carried. In this work, the influence of some factors (type of substrate, number and thickness of mortar layers) on the mechanical and physical performance of two mortars (site-made and industrial) was evaluated, using the following in-situ testing techniques: pendulum rebound hammer test (with two types of rebound hammer), ultrasonic pulse velocity test (with two types of device) and water absorption under low pressure test (with Karsten tubes). It was possible to verify that the above-mentioned factors influence the performance of the mortars. The in-situ testing techniques were, in general, able to identify differences in the behaviour of renders due to these factors. However, for the same technique, different devices sometimes led to distinct results. Nevertheless, the combination of the results of different techniques helped to reduce the uncertainty of the analysis.

Climate change studies already reported sea level rise as an accepted scenario, which induces changes in nearshore wave conditions. A large range of new experiences including water level, run-up, overtopping, hydrodynamic data for different wave steepnesses and directions was performed in the Leibniz Universität Hannover (LUH) wave basin for a rubble mound breakwater with a slope of 1(V):2(H). This work presents, focusing on oblique extreme wave conditions, numerical simulations of the hydrodynamics in that experiment using OpenFOAM®. Results of the wave generation boundary conditions and their propagation, namely levation of the water level free-surface and velocity data at specific locations are compared and discussed with data from experimental measurements acquired by acoustic wave gauges and acoustic doppler velocimeter (ADV) / Vectrino equipment. Although an exact match between numerical and laboratory values was not reached, an appropriate incident wave angle and a reasonable amplitude of velocities and water depths was achieved and the same happened to the statistics of those values.

The prediction of scour evolution at bridge foundations is of utmost importance forengineering design and infrastructures

Soil water content measurement is crucial during compaction control of embankments. The current techniques used to measure the soil water content in the field are outlined, and their advantages and limitations are indicated. Most techniques require destructive sampling and yields late results, or involve expensive equipment and are hard to set up. Low-cost capacitive and resistive moisture sensors entered successfully in last decades in agronomy applications to automatize crops irrigation. The purpose of this study is to identify whether these sensors are reliable to be used in geotechnical engineering and, in particular, to what extent can they aid compaction control of embankments. Three resistive sensors and two capacitive sensors are tested on five types of soils prepared with a wide range of water contents. The experimental procedures are described, and the sensors output data are compared with water contents obtained from the oven-drying technique. A new device that allows calibration of the sensors on compacted soils is developed. Soils characteristics that can influence moisture measurement using capacitive and resistive sensors are also explored. Test results suggest that some of the sensors can estimate the soil water content on compacted fine grained soils, when proper calibration procedure is successfully achieved. Sensors accuracy tend to increase as the soil void ratio decreases. Such sensors may be useful for expedite measurements, especially, when later counter-prof is available, or when a wide interval for the water content is acceptable.

Estuaries are coastal systems particularly vulnerableto climate change. Within these systems, agricultureis one of the most potentially affected sectors. This paperproposes a risk assessment approach for helping thedecision-making process at a local level, addressing two risksthat affect agricultural areas located in estuarine margins:the unavailability of freshwater for irrigation resulting fromthe upstream propagation of estuarine brackish water duringdroughts and land inundation by high water levels associatedwith high tides and storm surges. For each risk,quantitative consequence descriptors are proposed to supportrisk level determination and evaluation through a continuousconsequence

Abstract: Vertical air curtains are often used to separate two different zones to reduce contaminant transfer or even to provide aerodynamic sealing from one zone to the other. In this isothermal full-size experimental research work, the contaminant transfer between zones is reduced using an air extraction from the “contaminated” compartment and an air curtain. This work correlates the minimum exhaust air flow rate required to reach the aerodynamic sealing at the opening connecting two different zones with the jet nozzle velocity for small nozzle thicknesses (5 mm, 10 mm and 16 mm), particularly for Reynolds numbers below 3800. Following the experimental study, a general physical law that relates the jet parameters (angle, nozzle thickness and jet velocity at the nozzle) with the average velocity through the opening (for the condition of acceptable contaminant tightness) was obtained. The results showed that the average velocity of the flow across a door protected by an air curtain required to keep the aerodynamic sealing varies linearly with Re. The slope, however, is different below and above Re = 3820.

The geomechanical behaviour of railway ballast is a key aspect in the performance of ballasted tracks, mainly under increased axle loads and/or train speeds. Recently, and driven by the circular economy paradigm, some researchers have evaluated the use of alternative ballast materials as replacement for traditional natural crushed rocks. This work presents a comparison between the geomechanical behaviour of a granite aggregate and the one of an electrical arc furnace steel slag aggregate, with the trade designation of

A prestação dos serviços de água e esgotamento sanitário depende de infraestruturas constituídas por ativosde longa duração, com elevados custos de investimento, de construção e de reabilitação. Por essa razão, agestão de ativos, ou seja, a gestão estratégica e racional de infraestruturas, é atualmente reconhecida comoindispensável para a eficiência, a eficácia e a sustentabilidade dos serviços. Porém, essa prática ainda não estágeneralizada, havendo um longo caminho a percorrer. Os reguladores do setor têm uma especial responsabilidadepara alterarem a situação, sensibilizando a sociedade e os decisores políticos, contribuindo para umacultura de gestão que inclua o longo prazo, criando medidas promotoras de gestão de ativos. Este artigocontextualiza o tema e sistematiza medidas de regulação promotoras de uma melhor gestão de ativos.

Rehabilitation of facades may be carried out with the application of External Thermal Insulation Systems (ETICS). Their main contribution is the increase of the energy efficiency of buildings. In the literature, hygrothermal, impact and fire performance studies have been carried out on several systems with different insulation materials, such as expanded polystyrene, mineral wool and extruded polystyrene foam insulation. Due to the growing concern with the environment, systems are being developed with more sustainable and ecological materials, such as ICB (expanded cork). These type of boards are responsible for a negative impact in global warming potential, significantly improving the environmental benefits of their use. As these systems were recently introduced to the market, applications on site are very recent and their behaviour over time still unknown. In this research, the durability and global performance of more sustainable systems (with ICB) were analysed through an experimental campaign and compared with EPS (expanded polystyrene) systems. The results show that the systems with ICB obtained satisfactory global behaviour comparable with the EPS systems. The ICB sustainable systems analysed stood out in acoustic performance. ...