ABSTRACT Abstract The goal of this study was to explain the influence of the total porosity and t... more ABSTRACT Abstract The goal of this study was to explain the influence of the total porosity and the surface roughness on the susceptibility of clay bricks to biodegradation by phototrophic microorganisms. In addition, this correlation was studied on both specimens treated with TiO2 nanocoating and untreated control specimens. The effect of UV intensity on the photocatalytic power of TiO2 was also investigated. An accelerated fouling test was performed by sprinkling a suspension of Chlorella mirabilis and Chroococcidiopsis fissurarum on sample surfaces. These two test strains were chosen because their representativeness on building clay brick façades subjected to biofouling. The gradual superficial accumulation of algal biomass on treated and control specimens was evaluated by means of image analysis and colour measurement. Two specimens' parameters, namely porosity and roughness, were examined. Results showed that both the specimen microstructure and roughness of the surface play a key role in the colonization of clay bricks because they were able to provide more nutrient to the algal cells anchored to the surface. The TiO2 nanocoating was able to inhibit the biofouling of clay bricks irradiated with UV-A light, except in the case of high porous rough specimens.
... View Within Article. The following are the laboratory methods for characterisation: &#x02... more ... View Within Article. The following are the laboratory methods for characterisation: • porosimetry (with Porosimeter 2000 Series, Carlo Erba Instruments) aimed at the determination of the pores' distribution and the suction properties (Normal 4/80); ...
International Journal of Architectural Heritage, 2012
The reuse of ancient ceramic fragments in Romanesque masonries was a common practice in the Medie... more The reuse of ancient ceramic fragments in Romanesque masonries was a common practice in the Medieval era. A cultural impoverishment of the masonry building art characterized this period. Pre-existing structures were often exploited to build new masonries, both for civil and religious purpose. Starting from these general considerations, a specific construction technique of some Romanesque masonries of the Church of S. Maria in Portuno (Italy) and made by tile and brick fragments, was studied by a multidisciplinary approach. Analyses of the chemical, physical, and mechanical properties of the original materials (tile and brick fragments, mortars) were carried out by laboratory tests. Furthermore, some wall specimens were reproduced through the same ceramic materials and construction technique of the original masonries. Compression tests were carried out on these wall specimens so as to understand the influence of this construction technique on their compressive strength, Young's modulus, and failure mode. The results allowed increased current knowledge on historical materials and on the mechanical behavior of these specific historical masonries. Useful data obtained by experimental characterization of the materials and walls will also allow to guide future restoration works on these masonries.
International Journal of Architectural Heritage, 2010
In many historical buildings built between the 16th and 19th centuries, light vaults are present ... more In many historical buildings built between the 16th and 19th centuries, light vaults are present made by wooden structures and mats of reeds and plaster carrying frescoes or stuccoes of architectural and historical value on the lower surface. Some of these structures today are in a precarious state of conservation, and a wide program of rehabilitation has started, especially with
ABSTRACT We report the first results of a research study aimed at developing a new strategy for t... more ABSTRACT We report the first results of a research study aimed at developing a new strategy for the conservation of wooden structural elements present in historical buildings, based on moisture regulating systems. As has been happening for artefact preservation in museums, the idea is to develop systems based on the ability of some highly hygroscopic materials to moderate variations in relative humidity. These materials could adsorb and release moisture to reduce the extreme values of humidity in the micro-climate, for example between wooden beams and masonry. In order to experimentally verify this possibility using current, low cost and easy handling building materials, 5 bentonite samples were laboratory processed to improve their adsorbing properties by means of treatment with sodium carbonate at 3 concentrations: 2, 3 and 4% by weight. The effectiveness of ion exchange between sodium carbonate and bentonite was controlled by measuring the swelling volume of the bentonites. All the samples (n = 15) were tested for their hygroscopic properties. Adsorption isotherms were measured at 25 â—¦C, using desiccators with silica gel, saturated salt solutions and bi-distilled water. A comparison between isotherms of one of the lower hygroscopic treated sample of bentonite and of a sample of wood and of a sample of brick and some numerical analyses with the Delphin code were made in order to evaluate the potential use of this bentonite as a moisture regulating system for the preservation of historical wooden elements. Results show that it seems to be possible to use bentonites as a moisture buffering material in order to reduce moisture content in wooden beams at least during their adsorption phase. It remains to investigate their desorption phase and their behaviour if they be in a saturation condition. Further studies are currently under way.
... View Within Article. The following are the laboratory methods for characterisation: &#x02... more ... View Within Article. The following are the laboratory methods for characterisation: • porosimetry (with Porosimeter 2000 Series, Carlo Erba Instruments) aimed at the determination of the pores' distribution and the suction properties (Normal 4/80); ...
ABSTRACT Abstract The goal of this study was to explain the influence of the total porosity and t... more ABSTRACT Abstract The goal of this study was to explain the influence of the total porosity and the surface roughness on the susceptibility of clay bricks to biodegradation by phototrophic microorganisms. In addition, this correlation was studied on both specimens treated with TiO2 nanocoating and untreated control specimens. The effect of UV intensity on the photocatalytic power of TiO2 was also investigated. An accelerated fouling test was performed by sprinkling a suspension of Chlorella mirabilis and Chroococcidiopsis fissurarum on sample surfaces. These two test strains were chosen because their representativeness on building clay brick façades subjected to biofouling. The gradual superficial accumulation of algal biomass on treated and control specimens was evaluated by means of image analysis and colour measurement. Two specimens' parameters, namely porosity and roughness, were examined. Results showed that both the specimen microstructure and roughness of the surface play a key role in the colonization of clay bricks because they were able to provide more nutrient to the algal cells anchored to the surface. The TiO2 nanocoating was able to inhibit the biofouling of clay bricks irradiated with UV-A light, except in the case of high porous rough specimens.
Earthquake risk assessment at urban scale is generally based on the definition of indices concern... more Earthquake risk assessment at urban scale is generally based on the definition of indices concerning site hazard, buildings vulnerability and exposition, but does not consider human behavioural aspects during both earthquake and first post-event phases. Our work proposes a model for earthquake evacuation simulation, which is based on the analysis of real events. A Multi-agent architecture is adopted. Two kinds of agents are defined: “Pedestrian” defined by a behavioural model describing motion in earthquake evacuation; “Environment” defined by seismic data (e.g: earthquake magnitude) and modifications of the initial scenario due to earthquake (e.g: ruins formation). “Pedestrian” takes decisions based on obstacles avoidance, joining groups behaviours, own desired speed, driving terms. This paper provides a definition for the group attraction force that is based on the social force model, including modifications for the earthquake case. The software PEPES (Post-Earthquake Pedestrians ...
ABSTRACT Abstract The goal of this study was to explain the influence of the total porosity and t... more ABSTRACT Abstract The goal of this study was to explain the influence of the total porosity and the surface roughness on the susceptibility of clay bricks to biodegradation by phototrophic microorganisms. In addition, this correlation was studied on both specimens treated with TiO2 nanocoating and untreated control specimens. The effect of UV intensity on the photocatalytic power of TiO2 was also investigated. An accelerated fouling test was performed by sprinkling a suspension of Chlorella mirabilis and Chroococcidiopsis fissurarum on sample surfaces. These two test strains were chosen because their representativeness on building clay brick façades subjected to biofouling. The gradual superficial accumulation of algal biomass on treated and control specimens was evaluated by means of image analysis and colour measurement. Two specimens' parameters, namely porosity and roughness, were examined. Results showed that both the specimen microstructure and roughness of the surface play a key role in the colonization of clay bricks because they were able to provide more nutrient to the algal cells anchored to the surface. The TiO2 nanocoating was able to inhibit the biofouling of clay bricks irradiated with UV-A light, except in the case of high porous rough specimens.
... View Within Article. The following are the laboratory methods for characterisation: &#x02... more ... View Within Article. The following are the laboratory methods for characterisation: • porosimetry (with Porosimeter 2000 Series, Carlo Erba Instruments) aimed at the determination of the pores' distribution and the suction properties (Normal 4/80); ...
International Journal of Architectural Heritage, 2012
The reuse of ancient ceramic fragments in Romanesque masonries was a common practice in the Medie... more The reuse of ancient ceramic fragments in Romanesque masonries was a common practice in the Medieval era. A cultural impoverishment of the masonry building art characterized this period. Pre-existing structures were often exploited to build new masonries, both for civil and religious purpose. Starting from these general considerations, a specific construction technique of some Romanesque masonries of the Church of S. Maria in Portuno (Italy) and made by tile and brick fragments, was studied by a multidisciplinary approach. Analyses of the chemical, physical, and mechanical properties of the original materials (tile and brick fragments, mortars) were carried out by laboratory tests. Furthermore, some wall specimens were reproduced through the same ceramic materials and construction technique of the original masonries. Compression tests were carried out on these wall specimens so as to understand the influence of this construction technique on their compressive strength, Young's modulus, and failure mode. The results allowed increased current knowledge on historical materials and on the mechanical behavior of these specific historical masonries. Useful data obtained by experimental characterization of the materials and walls will also allow to guide future restoration works on these masonries.
International Journal of Architectural Heritage, 2010
In many historical buildings built between the 16th and 19th centuries, light vaults are present ... more In many historical buildings built between the 16th and 19th centuries, light vaults are present made by wooden structures and mats of reeds and plaster carrying frescoes or stuccoes of architectural and historical value on the lower surface. Some of these structures today are in a precarious state of conservation, and a wide program of rehabilitation has started, especially with
ABSTRACT We report the first results of a research study aimed at developing a new strategy for t... more ABSTRACT We report the first results of a research study aimed at developing a new strategy for the conservation of wooden structural elements present in historical buildings, based on moisture regulating systems. As has been happening for artefact preservation in museums, the idea is to develop systems based on the ability of some highly hygroscopic materials to moderate variations in relative humidity. These materials could adsorb and release moisture to reduce the extreme values of humidity in the micro-climate, for example between wooden beams and masonry. In order to experimentally verify this possibility using current, low cost and easy handling building materials, 5 bentonite samples were laboratory processed to improve their adsorbing properties by means of treatment with sodium carbonate at 3 concentrations: 2, 3 and 4% by weight. The effectiveness of ion exchange between sodium carbonate and bentonite was controlled by measuring the swelling volume of the bentonites. All the samples (n = 15) were tested for their hygroscopic properties. Adsorption isotherms were measured at 25 â—¦C, using desiccators with silica gel, saturated salt solutions and bi-distilled water. A comparison between isotherms of one of the lower hygroscopic treated sample of bentonite and of a sample of wood and of a sample of brick and some numerical analyses with the Delphin code were made in order to evaluate the potential use of this bentonite as a moisture regulating system for the preservation of historical wooden elements. Results show that it seems to be possible to use bentonites as a moisture buffering material in order to reduce moisture content in wooden beams at least during their adsorption phase. It remains to investigate their desorption phase and their behaviour if they be in a saturation condition. Further studies are currently under way.
... View Within Article. The following are the laboratory methods for characterisation: &#x02... more ... View Within Article. The following are the laboratory methods for characterisation: • porosimetry (with Porosimeter 2000 Series, Carlo Erba Instruments) aimed at the determination of the pores' distribution and the suction properties (Normal 4/80); ...
ABSTRACT Abstract The goal of this study was to explain the influence of the total porosity and t... more ABSTRACT Abstract The goal of this study was to explain the influence of the total porosity and the surface roughness on the susceptibility of clay bricks to biodegradation by phototrophic microorganisms. In addition, this correlation was studied on both specimens treated with TiO2 nanocoating and untreated control specimens. The effect of UV intensity on the photocatalytic power of TiO2 was also investigated. An accelerated fouling test was performed by sprinkling a suspension of Chlorella mirabilis and Chroococcidiopsis fissurarum on sample surfaces. These two test strains were chosen because their representativeness on building clay brick façades subjected to biofouling. The gradual superficial accumulation of algal biomass on treated and control specimens was evaluated by means of image analysis and colour measurement. Two specimens' parameters, namely porosity and roughness, were examined. Results showed that both the specimen microstructure and roughness of the surface play a key role in the colonization of clay bricks because they were able to provide more nutrient to the algal cells anchored to the surface. The TiO2 nanocoating was able to inhibit the biofouling of clay bricks irradiated with UV-A light, except in the case of high porous rough specimens.
Earthquake risk assessment at urban scale is generally based on the definition of indices concern... more Earthquake risk assessment at urban scale is generally based on the definition of indices concerning site hazard, buildings vulnerability and exposition, but does not consider human behavioural aspects during both earthquake and first post-event phases. Our work proposes a model for earthquake evacuation simulation, which is based on the analysis of real events. A Multi-agent architecture is adopted. Two kinds of agents are defined: “Pedestrian” defined by a behavioural model describing motion in earthquake evacuation; “Environment” defined by seismic data (e.g: earthquake magnitude) and modifications of the initial scenario due to earthquake (e.g: ruins formation). “Pedestrian” takes decisions based on obstacles avoidance, joining groups behaviours, own desired speed, driving terms. This paper provides a definition for the group attraction force that is based on the social force model, including modifications for the earthquake case. The software PEPES (Post-Earthquake Pedestrians ...
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