1,720,959 research outputs found
The problem of conservation of XX century architectural heritage: The fibreglass dome of the Woodpecker dance club in Milano Marittima (Italy)
Full text linkThe present study deals with the deterioration of materials in the dome of the “Woodpecker” dance club designed by the architect Filippo Monti (1928–2015) and built in Milano Marittima (near Ravenna, Italy) in 1968. This place, considered extremely valuable due to its landscape and architectural features, has been in a state of abandonment for around 40 years, but recently the local Municipality has started a process for its restoration. The dome is made of 23 fibreglass precast rib vaults hiding a steel structure, and in early 2000s a large part of its internal surface was painted with a graffito by Blu, an internationally renowned Italian street artist. Nowadays, both the dome and the graffito are safeguarded for their historic-architectural-artistic value by putting restrictions to their demolishment and modification. However, both the dome and the graffito are affected by harsh kinds of degradation, very different from those affecting historical building materials, which endanger their state of preservation. This study investigates whether the methodological approach of the conservative restoration can be applied to this structure, which is an example of contemporary architecture. Because of the lack of project drawings, a visual investigation was carried out to define geometric features and the most important technical details, and to deduce plausible hypotheses about building techniques that were adopted. The degradation affecting the dome and the graffito was then investigated, and samples of fibreglass, steel and paint were collected. Laboratory analyses on these samples, in addition to environmental studies concerning wind, ground water and relative humidity, were conducted to characterize the materials and identify their main deterioration processes. A possible restoration solution in accordance with conservative restoration principles was finally proposed, showing that the application of the same methodological approach used for ancient buildings arises many challenges, due to some key peculiarities of XX century architectural heritage materials
Onsite and laboratory assessment of repair mortars for reinforced concrete floor slabs in heritage buildings
No full textThe conservation and repair of XX century architectural heritage built with reinforced concrete is becoming more and more important and requires suitable materials and technical solutions. In particular, effectiveness, compatibility and durability must be ensured, in spite of the limited extent of demolition allowed by the local authorities, and the literature in this field is still limited. In this paper, an experimental campaign was carried out in an historic reinforced concrete floor slab, where different repair mortars were used. After some on-site testing on the corrosion potential, the concrete beams of the slab were integrally cut and transported to the laboratory for a series of systematic tests, aimed at investigating the performance and compatibility of the repair materials, as well as any possible issues hindering the success of this structural intervention. The filling ability, physical compatibility, chemical compatibility and mechanical compatibility of the repair mortars and the corrosion behavior of the steel reinforcement were investigated, deriving some results of general interest, which may contribute to a better insight about the repair of heritage concrete floor slabs
Developing inorganic coatings with nano-TiO2 for heritage concrete and assessing their self-cleaning performance by a new laboratory test
Full text linkHeritage concrete and cement mortars urgently need preventive treatments which slow down their deterioration, allow to avoid extensive demolition and reconstruction, and preserve the aesthetic significance of texturized surfaces. In this paper new inorganic treatments were developed, which combine the self-cleaning behaviour of nano-TiO2 and the beneficial effect of inorganic consolidants. In a preliminary phase, two consolidants were investigated for the incorporation of titania nanoparticles, namely diammonium phosphate and ethyl silicate (TEOS), and the latter one was selected as the most promising one. In the second phase, combined treatments with TEOS and titania nanoparticles were developed and applied by different techniques to cement mortars manufactured to mimic historic substrates, providing a novel and valuable solution for heritage concrete protection that is unprecedented in the literature. Besides evaluating the photoactivity of the treatments in terms of methylene blue discolouration, a novel test was developed in this study to assess in a more realistic way the actual ability of the treatments to boost the removal of soiling by rain. The combination of TEOS and nano-TiO2 into a single treatment has the potential to slow down carbonation and chloride diffusion, to help the removal of soiling and to provide the substrates with antimicrobial activity, hence it can be considered highly innovative. The results also showed that more realistic laboratory assessment procedures are necessary to predict the actual effectiveness of the treatments when applied to real substrates and exposed to real outdoor conditions. The novel test proposed and applied in this study may serve as a basis for the development of a new procedure of assessment of self-cleaning ability
Evaluating water-repellents applied to brick masonry: An experimental study by thermal imaging and water transport properties’ characterization
Full text linkMoisture is one of the main problems that affect new and historic masonry buildings, which are the most common ones in Europe and worldwide. The application of surface treatments based on water-repellents is a very common solution to protect masonry from rain and hence from moisture-related problems. However, there are very few studies on the monitoring of water-repellents in real buildings and a deeper knowledge would be necessary on the long-term effectiveness and compatibility of water repellents, especially considering that defects and flaking issues are often reported in-the-field. In this paper, infrared thermography was proposed as a totally non-invasive technique to monitor the behaviour of brick masonry subjected to wetting, both from outside (rain) and inside (internal moisture). An active thermal approach was used to simulate internal and external wetting. The behaviour of the masonry during wetting and drying was investigated both in laboratory walls and in brick samples, to elucidate their water transport properties. All the materials were tested both in untreated conditions and after the application of two different hydrophobic coatings. The results show that the drying behaviour of treated masonry materials is a critical issue, as the coatings may strongly slow down the drying of internal moisture, even if the coefficient of resistance to water vapour diffusion of the products is very low. The results also suggest that the methodology used to process thermal images using multi-temporal analysis is a promising way to interpret the water transport in treated walls and to monitor real buildings where water-repellents were applied
Preliminary results on the use of ammonium phosphate solutions for the consolidation of lime-based mortars
No full textIn this study, a preliminary evaluation of the effectiveness of aqueous solutions of diammonium hydrogen phosphate (DAP) for the consolidation of lime-based mortars is reported. Four types of mortars were considered: 2 lime-based mortars (containing either siliceous or calcareous aggregates), 1 lime-based mortar also containing brick powder as a pozzolanic addition (so-called “cocciopesto” mortar) and 1 mortar based on natural hydraulic lime. Two different formulations of the DAP solution were considered, differing in terms of DAP concentration, CaCl2 addition as a calcium source and ethanol addition to boost formation of calcium phosphate (CaP) phases. First, for the various types of mortar, the nature and the morphology of the new CaP phases were investigated by FT-IR and SEM. Then, the mechanical benefit resulting from the new CaP was evaluated, in terms of increase in dynamic elastic modulus and compressive strength. The microstructural compatibility of the treatments was also evaluated, by determining the alterations in pore size distribution. The results of the study indicate that new CaP phases are formed after 24 hours for both DAP concentrations, the amount of new phases and the mechanical improvement being higher for the more concentrated solution. In no case did dramatic pore occlusion and alteration in the pore size distribution take place, which allows expecting no dramatic alteration in the mortar ability to exchange water and water vapour with the environment. The more concentrated solution caused some visible colour change in the case of mortars not originally white (“cocciopesto” and NHL mortars), which makes the use of less concentrated solutions advisable on those substrates
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
3D Data Management and Thermographic Studies as a Knowledge Base for the Conservation of a Rationalist Architecture
No full textThanks to the development of technologies for digitalization, new possibilities of management and valorization of Cultural Heritage have been opened. These issues are addressed by the project IDEHA (Innovation for Data Elaboration in Heritage Areas), funded by MIUR Italian Ministry, for Italian assets of historical interest. Among the different case studies, the library tower of the XX Century complex of the Faculty of Engineering in Bologna has a great significance as an example of rationalist architecture. The present work aims at the 3D digitization of the tower, the analysis of its state of maintenance by using active thermography and the implementation of a BIM model that contains all these information. Aerial (by UAV) and terrestrial photogrammetry was used for the development of the three-dimensional model. From the acquired images, a point cloud and a textured mesh of the Tower were processed. The point cloud was also used as a reference for the elaboration of an HBIM model representing both the interior and exterior of the tower structure. Moreover, a study of the conditions of the external facades recently treated with water repellent was conducted through active thermography. The study of the state of the external brick wall face was carried out through the multi-temporal analysis of thermal images. This allowed to identify the areas where the water repellent treatment is damaged and therefore more exposed to deterioration phenomena. The main challenge of this research work is to incorporate the information acquired through active thermography into the information model in order to better manage the building
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
