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In the recent past, the NOx removal efficiency of photocatalytic materials has been subject of many studies with promising results. However, many of these studies involve laboratory tests carried out under standardized climatic exposure conditions, often not representative of the real world environment. With the aim to bridge this gap, selected photocatalytic materials have been applied to different substrates in outdoor demonstrator platforms at pilot scale as part of the project LIFE-PHOTOSCALING. The paper presents the results of in situ measurements of NOx removal efficiency of the materials, performed during 17 months. Statistical models accounting for the influence of exposure time and relevant environmental variables are derived. They suggest that photocatalytic emulsions on the tested asphalt experience a significant loss of activity over time irrespective of climatic conditions. The efficiency of photocatalytic slurries on asphalt and of concrete tiles, with the photocatalyst applied on surface or in bulk, mainly depends on substrate humidity.

Concrete moisture is the most significant parameter with respect to its durability, however the data on moisture content in real-size structures are scarce in contrast to the numerous literature published on laboratory experiments. The majority of laboratory tests have been performed in chambers with controlled hydrothermal regime, in general to enable the concrete to reach equilibrium and steadystate conditions. However, real weather induces permanent nonsteady state situations due to the evolution of temperature and climatic events as snowing or raining.Present paper discusses the effect of climatic events on the hydrothermal performance of concrete and their influence on reinforcement corrosion process. Concerning the moisture level, the degree of saturation, S W , and not the internal relative humidity has been identified to be the controlling parameter of the corrosion process. The psychometric chart and the S W -RH plots are very suitable to study the hydrothermal behaviour. With respect to the corrosion parameters, corrosion potential, resistivity and corrosion rates, they are very influenced by temperature in a complex manner. The temperature is the main factor influencing the degree of saturation in sheltered conditions while rain and snow are so, in unsheltered ones. In opposition, however, what can be expected, climates with higher temperatures are less aggressive than colder ones, except when rain periods are produced during the hotter periods.Die Betonfeuchtigkeit ist der wichtigste Parameter bezüglich der Dauerhaftigkeit des Stahlbetons. Im Gegensatz zu einer Vielzahl von veröffentlichten Daten aus Laborversuchen gibt es jedoch nur wenige Angaben über den Feuchtigkeitsgehalt in realen Bauwerken. Die Mehrzahl der Laborversuche wurde in Prüfkammern mit kontrollierten hydrothermischen Zuständen durchgeführt; in der Regel um Gleichgewichtsbedingungen im Beton zu erreichen. Bei realem Wetter liegen durch Temperaturschwankungen und durch klimatische Ereignisse wie Regen oder Schnee jedoch dauernd Nichtgleichgewichtszustände vor.Die vorliegende Arbeit diskutiert den Einfluss klimatischer Ereignisse auf das hydrothermische Verhalten von Beton und deren Einfluss auf den Bewehrungsstahlkorrosionsprozess. Bezüglich des Feuchtigkeitslevels wurde der Sättigungsgrad, S W , und nicht die interne relative Feuchtigkeit als der bestimmende Parameter des Korrosionsprozesses identifiziert. Die Feuchtigkeitsdarstellung und die S W -RH-Diagramme sind sehr gut geeignet, das hydrothermische Verhalten zu untersuchen. Die Korrosionsparameter (Korrosionspotential, Widerstand und Korrosionsgeschwindigkeit) werden sehr komplex von der Temperatur beeinflusst. Die Temperatur ist der wesentliche Faktor, der den Sättigungsgrad unter geschützten Bedingungen beeinflusst, während unter ungeschützten Bedingungen Regen und Schnee entscheidend sind. Im Gegensatz zu dem, was erwartet werden kann, ist jedoch ein Klima mit höheren Temperaturen weniger aggressiv als eines mit kälteren Temperaturen; außer wenn Regenperioden während heißerer Z...

After more than two years wearing surgical masks due to the COVID-19 pandemic, used masks have become a significant risk for ecosystems, as they are producing wastes in huge amounts. They are a potential source of disturbance by themselves and as microplastic contamination in the water system. As 5500 tons of face masks are estimated to be used each year, there is an urgent need to manage them according to the circular economy principles and avoid their inadequate disposal. In this paper, surgical wear masks (WM), without any further pretreatment, have been introduced as addition to mortars up to 5% in the weight of cement. Mechanical and microstructural characterization have been carried out. The results indicate that adding MW to the cement supposes a decrease in the properties of the material, concerning both strength and durability behavior. However, even adding a 5% of WM in weight of cement, the aspect of the mortars is quite good, the flexural strength is not significantly affected, and the strength and durability parameters are maintained at levels that—even lower than the reference—are quite reasonable for use. Provided that the worldwide production of cement is around 4.1 Bt/year, the introduction of a 5% of WM in less than 1% of the cement produced, would make it possible to get rid of the mask waste being produced.

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