The issue of maintenance is steadily emerging in the framework of the built environment, sharing its boundary with the one of durability. The definition of maintenance programme and maintenance plan for building components requires a preventive assessment of durability. Knowing the aptitude of materials overtime, and consequently of building components, is the optimal way to predict the dynamics of their performance. The combination of these concepts with the increasingly development of photoactive materials led to the research field of this thesis. Anatase phase titanium dioxide TiO2 is the largest used photocatalyst, with increasing applications. Moreover, its contribution to the mixture in the production of mortar allows to exploit its photoactivated depolluting and self-cleaning potential, by means of hydrophilicity. These properties reveal their effects by means of the contribution of solar energy (UV radiation), able to activate the photo catalysis through chemical reactions. This study, indeed, concerns photocatalytic cements, a topic already faced by many, which served as basic knowledge of our study. Such study reports data resulting from experimental tests, which investigate the performance of different samples, in terms of appraisal of durability and loss of performance overtime, through accelerated ageing tests. Several behaviours have been observed on specimens with different characterization, in terms of composition and surface finishing. Results achieved constitute a starting point for predicting the service life of buildings components, granting the transfer of information from materials to systems, in this case the cement-based building envelope. Information promotes wise planning of maintenance interventions and control of the global costs.
Il tema della manutenzione acquisisce sempre maggiore rilevanza nell'ampio contesto degli interventi sul costruito. Una corretta definizione dei piani e programmi di manutenzione dei componenti edilizi richiede però valutazioni preventive sulla loro durabilità. Conoscere l’attitudine dei materiali nel tempo, e quindi dei componenti edilizi, è il modo migliore per prevedere la dinamica delle loro prestazioni. In questo senso, le conoscenze durabilistiche completano il concetto di manutenzione, risultandone mutualmente vincolati. Il core della tesi nasce dalla congiunzione di questi concetti, uniti agli studi emergenti sui materiali innovativi. Il biossido di titanio è uno tra i più noti foto-catalizzatori, sempre più sfruttato in applicazioni architettoniche per le sue qualità. Il suo contributo nei materiali cementizi, in particolare nelle malte, favorisce l’esplicazione di proprietà anti inquinanti e di autopulizia. La condizione essenziale per l’esistenza di tali caratteristiche è che la sua superficie sia “attivata” da radiazioni UV, responsabili dell’innesco di processi di fotocatalisi. I materiali indagati sono infatti cementi fotocatalitici, i cui studi precedenti hanno costituito le conoscenze di base per intraprendere quello corrente. La ricerca sistematizza i risultati di una campagna sperimentale che valuta le prestazioni di campioni rappresentativi, in termini di decadimenti prestazionali paralleli al loro invecchiamento, tramite prove di invecchiamento accelerato. Sono stati osservati e valutati comportamenti diversi al variare della caratterizzazione del materiale. Gli esiti delle prove vorrebbero permettere il trasferimento delle informazioni dal materiale al prodotto, per essere sfruttate nell’ambito della programmazione degli interventi di manutenzione.
Experimental measurements for durability assessment of photocatalytic materials
MASSARI, SILVIA;LUONGO, NICOLETTA
2016/2017
Abstract
The issue of maintenance is steadily emerging in the framework of the built environment, sharing its boundary with the one of durability. The definition of maintenance programme and maintenance plan for building components requires a preventive assessment of durability. Knowing the aptitude of materials overtime, and consequently of building components, is the optimal way to predict the dynamics of their performance. The combination of these concepts with the increasingly development of photoactive materials led to the research field of this thesis. Anatase phase titanium dioxide TiO2 is the largest used photocatalyst, with increasing applications. Moreover, its contribution to the mixture in the production of mortar allows to exploit its photoactivated depolluting and self-cleaning potential, by means of hydrophilicity. These properties reveal their effects by means of the contribution of solar energy (UV radiation), able to activate the photo catalysis through chemical reactions. This study, indeed, concerns photocatalytic cements, a topic already faced by many, which served as basic knowledge of our study. Such study reports data resulting from experimental tests, which investigate the performance of different samples, in terms of appraisal of durability and loss of performance overtime, through accelerated ageing tests. Several behaviours have been observed on specimens with different characterization, in terms of composition and surface finishing. Results achieved constitute a starting point for predicting the service life of buildings components, granting the transfer of information from materials to systems, in this case the cement-based building envelope. Information promotes wise planning of maintenance interventions and control of the global costs.File | Dimensione | Formato | |
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https://hdl.handle.net/10589/138566