The following research takes advantage of recent advances in the field of structural materials with self-healing capabilities and presents the results of an experimental program focused on the development of sustainable, self-healing TRM systems. A total of 252 specimens were made, including 108 TRM composites consisting of a layer of glass fiber fabric embedded in a prism of CEM II-based mortar. 144 additional specimens consisting of the cementitious matrix alone were produced in order to assess the mechanical properties of the TRM composites. Two different approaches were followed to impart self-healing characteristics: (a) incorporation of crystalline additives into the cementitious mortar during mortar mixing, (b) coating the reinforcement fabric with an inorganic slurry of crystalline additives and/or silica fume. All specimens were placed inside two different healing environments: half in tap water from the Milan city water supply and half in salt water with NaCl concentration of 35 g/l, to recreate marine conditions. After 28 days, the TRM specimens were pre-cracked until a residual crack opening of 0,2 mm was reached, and the effectiveness of self-healing was evaluated through capillary absorption tests and mechanical tests after an additional month of conditioning tap water or salt water. Flexural and compression tests were also performed on the specimens consisting of only matrix at the same age to evaluate the residual performance of the cracked TRM specimens. The results were evaluated in terms of capillary absorption, crack sealing and residual mechanical properties, paving the way towards the development of sustainable self-healing TRM systems.
La seguente ricerca sfrutta i recenti progressi nel campo dei materiali strutturali con capacità di autoguarigione e presenta i risultati di un programma sperimentale incentrato sullo sviluppo di malte cementizie rinforzate con tessuti (TRM - Textile Reinforced Mortar) sostenibili e autorigeneranti. Sono stati realizzati 252 campioni, di cui 108 compositi TRM costituiti da uno strato di tessuto in fibra di vetro incorporato in un prisma di malta a base di CEM II. I 144 provini composti dalla sola matrice cementizia sono stati prodotti per poter interpretare correttamente il recupero meccanico dei campioni compositi. Per conferire le caratteristiche di autoguarigione sono stati seguiti due approcci diversi : (a) l'incorporazione di additivi cristallini nella matrice cementizia durante la miscelazione della malta, b) il rivestimento del tessuto di rinforzo con un impasto inorganico di additivi cristallini e/o fumo di silice. Tutti i provini sono stati posizionati all'interno di due differenti ambienti di guarigione: metà in acqua potabile della rete idrica cittadina di Milano e metà in acqua salata con una concentrazione di NaCl pari a 35 g/l, per ricreare le condizioni marine. Dopo 28 giorni, i campioni TRM sono stati pre-fessurati fino al raggiungimento di un'apertura residua dell'imbocco della fessura pari a 0,2 mm, e l'efficacia dell'autoguarigione è stata valutata attraverso prove di assorbimento capillare e prove meccaniche dopo un ulteriore mese di condizionamento aggiuntivo in acqua o in acqua salata. Sono state inoltre eseguite prove di flessione e compressione sui campioni costituiti da sola matrice alla stessa età, per valutare le prestazioni residue dei provini TRM fessurati. I risultati sono stati valutati in termini di assorbimento capillare, sigillatura delle fessure e proprietà meccaniche residue, aprendo la strada verso lo sviluppo di sistemi TRM autorigeneranti sostenibili.
Sistemi TRM autorigeneranti : sviluppo sperimentale di sistemi TRM autorigeneranti per il retrofitting strutturale
ELIGIO, ISABELLA
2023/2024
Abstract
The following research takes advantage of recent advances in the field of structural materials with self-healing capabilities and presents the results of an experimental program focused on the development of sustainable, self-healing TRM systems. A total of 252 specimens were made, including 108 TRM composites consisting of a layer of glass fiber fabric embedded in a prism of CEM II-based mortar. 144 additional specimens consisting of the cementitious matrix alone were produced in order to assess the mechanical properties of the TRM composites. Two different approaches were followed to impart self-healing characteristics: (a) incorporation of crystalline additives into the cementitious mortar during mortar mixing, (b) coating the reinforcement fabric with an inorganic slurry of crystalline additives and/or silica fume. All specimens were placed inside two different healing environments: half in tap water from the Milan city water supply and half in salt water with NaCl concentration of 35 g/l, to recreate marine conditions. After 28 days, the TRM specimens were pre-cracked until a residual crack opening of 0,2 mm was reached, and the effectiveness of self-healing was evaluated through capillary absorption tests and mechanical tests after an additional month of conditioning tap water or salt water. Flexural and compression tests were also performed on the specimens consisting of only matrix at the same age to evaluate the residual performance of the cracked TRM specimens. The results were evaluated in terms of capillary absorption, crack sealing and residual mechanical properties, paving the way towards the development of sustainable self-healing TRM systems.| File | Dimensione | Formato | |
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2025_aprile_Eligio.pdf
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Descrizione: Sviluppo sperimentale di sistemi TRM autorigeneranti per il retrofitting strutturale
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https://hdl.handle.net/10589/235979