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It is generally agreed that the role played by aerosols in determining the air quality in urban areas is steadily increasing. As well as being among the main agents responsible for today’s atmospheric pollution, atmospheric particles are also recognized to participate actively in damage layer formation. In fact, recent years have witnessed a marked acceleration in surface soiling phenomena, as can be observed in the continual blackening of monument surfaces located in polluted areas. While numerous authors have performed detailed studies on the impact of the sulphation process in monument decay on a world-wide scale, surface blackening remains in need of in-depth investigation. The EC project CARAMEL (Carbon content and origin of damage layers in European monuments) has as one of its fundamental work steps the analytical study of black crusts collected at different monuments located in European urban sites. The aim is to create a data base of the carbon fraction concentrations present, and understand their relationship with the content of aerosol carbon components.

The availability of a correct, accurate and reproducible analytical method for a complete carbon balance in black crusts is of major importance in understanding the effects of the interaction between atmospheric pollutants and the environment, particularly in the partitioning of pollutant sources, damage mechanism identification, and a sustainable protection of cultural heritage. The EC Project CARAMEL has among its primary goal the setting up of a suitable and reliable analytic technique able to distinguish and measure carbon fractions in damage layers, particularly elemental carbon. The presence of a significant amount of carbonate carbon and the removal of organic carbon are critical steps in the measurement of carbon compounds in black crusts. A chemical-thermal methodology for carbon analyses in black crusts was set up, whose specificity, accuracy and precision was tested on appropriate standard samples. The results obtained indicate that the methodology satisfactorily distinguishes among carbon species and allows a reliable evaluation of their quantities in damage layers.

The availability of a correct, accurate and reproducible analytical method for a complete carbon balance in black crusts is of major importance in understand the effects of the interaction between atmospheric pollutants and the environment, particularly in the portioning of pollutant sources, damage mechanism identification, and a sustainable protection of cultural heritage. The EC Project CARAMEL has, among its primary goal, the setting up of a suitable and reliable analytic technique able to distinguish and measure carbon fractions in damage layers, particularly elemental carbon. The presence of a significant amount of carbonate carbon and the removal of organic carbon are critical steps in the measurement of carbon compounds in black crusts. A chemical-thermal methodology for carbon analyses in black crusts was set up whose specificity, accuracy and precision were tested on appropriate standard samples. The results obtained indicate that the methodology satisfactorily distinguishes among carbon species an allows a reliable evaluation of their quantities in damage layers.

Following our studies on resorcin[4]arenes, we synthesized new macrocycles containing cyanomethyl and aminomethyl side chains. Three stereoisomers (2a-c) of the former were obtained by BF3*Et2O tetramerization of the corresponding trans-cinnamic acid derivative and were shown to be in the 1,2-alternate, cone, and 1,3-alternate conformations. Conversely, the tetraamino derivative 6a in the cone conformation was prepared from the corresponding tetrabromide 3a. The interactions with Cu(II) cations of the new compounds were analyzed by measurements of 1H NMR and EPR spectra in parallel with molecular modeling calculations.

Sulphation of mortars and concretes is a function of diverse environmental factors (SO2 aerosol, temperature, etc) as well as some material characteristics. One of the phases that could be formed as consequence of the sulphation of the hydraulic binder is thaumasite. In this paper different hydraulic mortars have been exposed to laboratory exposure chambers in order to reproduce thaumasite formation due to atmospheric SO2. Under the laboratory exposure conditions, thaumasite was formed in hydraulic lime mortars, and mortars elaborated with ordinary Portland cement as well as mineralized white portland cement. However, thaumasite was not formed in mortars made of lime and pozzolan. The first product formed as a result of the SO2-mortar interaction was gypsum. Gypsum reacted with calcite and C-S-H gel, present in the samples, giving place to thaumasite. Low temperature promotes thaumasite formation., La sulfatación de morteros y hormigones depende de las condiciones ambientales (SO2 aerosol, temperatura, etc.), así como de las características del material. Una de las fases que se puede formar como consecuencia de la sulfatación de los ligantes hidráulicos es la taumasita. En este trabajo se han expuesto diferentes morteros hidráulicos en cámaras de laboratorio con el fin de reproducir la formación de taumasita por efecto del SO2 atmosférico. Bajo las condiciones de laboratorio se formó taumasita en los morteros de cal hidráulica y en los morteros fabricados con cemento portland y cemento blanco mineralizado. Sin embargo, cuando el ligante utilizado en los morteros fue cal y puzolana, no se formó taumasita. El yeso fue el primer producto formado en la interacción entre los morteros y el SO2. A continuación, este yeso reaccionó con la calcita y el gel C-S-H dando lugar a la formación de taumasita. Las bajas temperaturas favorecieron la formación de taumasita.

[EN]Sulphation of mortars and concretes is a function of diverse environmental factors (SO^ aerosol, temperature, etc) as well as some material characteristics. One of the phases that could be formed as consequence of the sulphation of the hydraulic binder is thaumasite. In this paper different hydraulic mortars have been exposed to laboratory exposure chambers in order to reproduce thaumasite formation due to atmospheric SO^. Under the laboratory exposure conditions, thaumasite was formed in hydraulic lime mortars, and mortars elaborated with ordinary Portland cement as well as mineralized white portland cement. However, thaumasite was not formed in mortars made of lime and pozzolan. The first product formed as a result of the SO^-mortar interaction was gypsum. Gypsum reacted with calcite and C-S-H gel. present in the samples, giving place to thaumasite. Low temperature promotes thaumasite formation., [ES]La sulfatación de morteros y hormigones depende de las condiciones ambientales (SO^ aerosol, temperatura, etc.), así como de las características del material. Una de las fases que se puede formar como consecuencia de la sulfatación de los ligantes hidráulicos es la taumasita. En este trabajo se han expuesto diferentes morteros hidráulicos en cámaras de laboratorio con el fin de reproducir la formación de taumasita por efecto del SO^ atmosférico. Bajo las condiciones de laboratorio se formó taumasita en los morteros de cal hidráulica y en los morteros fabricados con cemento port land y cemento blanco mineralizado. Sin embargo, cuando el ligante utilizado en los morteros fue cal y puzolana, no se formó taumasita. El yeso fue el primer producto formado en la interacción entre los morteros y el SO^. A continuación, este yeso reaccionó con la calcita y el gel C-S-H dando lugar a la formación de taumasita. Las bajas temperaturas favorecieron la formación de taumasita.