Browsing by Author "Borsoi, Giovanni"
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- Discussão de estratégias para a avaliação da biocolonização em ETICS : um caso de estudo em LisboaPublication . Borsoi, Giovanni; Parracha, João Luís; de Cooman, Quinten; Flores-Coles, Inês; Viegas, Cristina A.; Nunes, Lina; Moreira, Leonilde M.; Veiga, RosárioConservar e Reabilitar monumentos, edifícios e espaços são oportunidades únicas para fomentar a sustentabilidade dos territórios, constituindo-se o ENCORE 2020 - 4º Encontro de Conservação e Reabilitação de Edifícios numa ocasião ímpar para discutir os desafios da transformação no espaço construído: otimizar recursos, reutilizar materiais, melhorar a eficiência energética, repensar as centralidades urbanas, promover a resiliência. O presente documento junta os textos das comunicações apresentadas sobre a multiplicidade de aspetos que se entrecruzam no âmbito da intervenção no património construído, identificando, de forma multidisciplinar e sinergética, os desafios e os caminhos para melhor Conservar e Reabilitar.
- Effects of hygrothermal, UV and SO₂ accelerated ageing on the durability of ETICS in urban environmentsPublication . Parracha, João Luís; Borsoi, Giovanni; Veiga, Rosário; Flores-Colen, Inês; Nunes, Lina; Garcia, Ana R.; Ilharco, Laura M.; Dionísio, Amélia; Faria, PaulinaExternal Thermal Insulation Composite Systems (ETICS) have been extensively used for either new constructions or building facades retrofitting in the last decades. These systems can provide improved thermal performance to the building envelope. However, their long-term durability remains a pervasive concern, with some systems presenting relevant anomalies after few years from their application. The durability assessment of ETICS is defined by the EAD 040083-00-0404 guideline, which stated an accelerated ageing procedure based on the hygrothermal and freeze-thaw behaviour. Nevertheless, further important environmental urban conditions, such as UV radiation and atmospheric pollutants, as well as bio-susceptibility, are not envisaged in the guideline. This paper presents the results of an experimental campaign with the aim of evaluating the durability of the rendering system of several commercially available ETICS exposed to an innovative accelerated ageing procedure, which consists of hygrothermal cycles, UV radiation and air pollutants (SO₂) exposure. Physical and chemical-morphological tests were carried out prior and after each ageing cycle in order to evaluate the durability of ETICS. Biological susceptibility to moulds was also assessed. The experimental results showed that both surface hardness and surface gloss decreased after the combined effect of the hygrothermal, UV, and SO₂ ageing cycles, whereas an increase of surface roughness was observed. Substantial colour change for all systems after the ageing procedure was observed, confirming aesthetic alteration. Traces of biological growth were detected on the systems after ageing and the contact angle decreased after the hygrothermal cycles, indicating a lower surface hydrophobicity of the systems.
- Evaluation of ETICS characteristics that affect surface mould developmentPublication . Parracha, João Luís; Cortay, Armand; Borsoi, Giovanni; Veiga, Rosário; Nunes, LinaExternal Thermal Insulation Composite Systems (ETICS) are nowadays often used in new constructions but are also one of the most frequently used thermal retrofitting solutions for buildings. These systems have several advantages such as low installation cost, ease of application and increased thermal efficiency. Nevertheless, a number of questions have been raised on their long-time durability particularly related to biodeterioration. Biological growth is strongly influenced by several parameters, such as water content, temperature, pH but also by the type and hygroscopic properties of the building materials. It is therefore essential to understand and correlate those properties with biological growth. This paper aims at evaluating some ETICS characteristics that might influence surface mould development which is recognized as one of the major groups of deteriorating organisms. The susceptibility of the surface finishing layer and thermal insulation to biological growth was assessed through natural inocula and selected fungi and, whenever possible, correlated with water absorption and drying capacity. This study is part of a wider research project: WGB_Shield (Shielding building‘ facades on cities revitalization. Triple-resistance for water, graffiti and biocolonization of external thermal insulation systems) that aims at the development of ETICS with improved durability in the urban environment. Further development on this issue are ongoing.
- Impact of Water-Repellent Products on the Moisture Transport Properties and Mould Susceptibility of External Thermal Insulation Composite SystemsPublication . Roncon, Renata; Borsoi, Giovanni; Parracha, João Luís; Flores-Colen, Inês; Veiga, Rosário; Nunes, LinaExternal Thermal Insulation Composite Systems (ETICS) are constructive solutions widely used to increase the thermal insulation in new and retrofitted buildings. However, these systems can present several anomalies due to their constant exposure to weathering agents and anthropic factors. Water is generally the major cause of degradation. Thus, the application of water-repellent products can minimize the appearance of anomalies and increase the durability of the systems. In this paper, acrylic-based and siloxane-based hydrophobic products were applied to ETICS, with the aim of assessing the compatibility, effectiveness, and durability of these products. The moisture transport properties and mould susceptibility were assessed through laboratory tests on untreated and treated specimens. The durability of the hydrophobic treatments was also evaluated through artificial aging tests (heat-cold and freeze-thaw cycles). Results show that the protection products generally decreased water absorption, slightly decreased the drying rate, and presented adequate water vapor permeability. After aging, the products still had reasonable effectiveness and, with one exception, improved the water vapor diffusion of the systems. Additionally, ETICS underwent an alteration in the finishing coat (possible modification of the porosity) due to the aging cycles. No clear linear correlation was found between the contact angle values and water absorption results, evidencing the influence of other factors related to the composition of the water-repellent products.
- Performance parameters of ETICS : Correlating water resistance, bio-susceptibility and surface propertiesPublication . Parracha, João Luís; Borsoi, Giovanni; Flores-Colen, Inês; Veiga, Rosário; Nunes, Lina; Dionísio, Amélia; Gomes, M. Glória; Faria, PaulinaThe use of External Thermal Insulation Composite Systems (ETICS) significantly increased in the last decades due to their enhanced thermal properties, low installation cost and ease of application, not only in new constructions but also for thermal retrofitting of building facades. These multilayer rendering systems are constantly exposed to weathering agents and anthropic factors which can lead to physical-mechanical and aesthetical anomalies and thus affect their durability. However, possible synergetic effects among these agents are often neglected by international technical documents on the evaluation of the effectiveness and durability of ETICS. With the aim of filling this gap, moisture transport properties (capillary water absorption, water vapor permeability, water absorption under low pressure, and drying kinetics), thermal conductivity, mould susceptibility and surface properties (color, gloss, and roughness) of twelve commercially available ETICS were assessed and discussed. Possible links between these factors were analyzed and ETICS performance parameters were defined. Results demonstrate that a deeper knowledge of the correlation among ETICS properties can effectively contribute to the evaluation of the efficiency and long-term durability of these systems.