Study of innovative water repellent systems for the preservation and restoration of artificial stone materials

dc.contributor.advisor	Zendri, Elisabetta
dc.contributor.author	Falchi, Laura <1985>	it_IT
dc.date.accessioned	2014-03-15T12:10:02Z
dc.date.available	2015-01-17T09:36:17Z
dc.date.issued	2013-12-21
dc.identifier.uri	http://hdl.handle.net/10579/3969
dc.description.abstract	The thesis deals with the study and development of water repellent mortars, made with water- repellent admixtures , suitable for the protection, maintenance and restoration of historical and civil buidings. This study deals with the damage processes due to the action of water (both as direct action and or as carrier of pollutants and soluble salts) on the building materials and evaluates the durability of water-repellent mortars in different environmental conditions. The study considers the interactions of different water repellent admixtures on the hydration reactions of some binders and the resistance to the physical degradation due to the crystallization of soluble salts or the exposure to UV light and rain. Some mixes were applied also on salty masonries. Different analytical techniques (FT-IR, TG-DSC, SEM-EDX, XRD), test according to the european normative, porosimetric ultrasonic measurements and IR- thermography were used.	it_IT
dc.description.abstract	Il lavoro di tesi riguarda lo studio di malte idrorepellenti preparate con l’utilizzo di additivi idrofobizzanti per la protezione, la manutenzione e il recupero delle superfici architettoniche storiche e civili. Questo studio considera in particolare i processi di degrado causati dalla presenza di acqua (per azione diretta o come mezzo di trasporto di inquinanti e sali solubili) sui materiali dell’edilizia e valuta la durabilità di malte idrorepellenti in varie condizioni ambientali. Lo studio ha considerato l’influenza di diversi additivi idrorepellenti sull’idratazione di alcuni leganti e la resistenza all’azione di degrado fisico conseguente la cristallizzazione di Sali o l’esposizione a radiazioni UV e alla pioggia. Alcuni impasti sono stati applicati su modelli di murature sottoposti a risalita capillare di soluzioni saline. Lo sviluppo della ricerca ha previsto il ricorso a numerose tecniche analitiche (FT-IR, TG-DSC, SEM-EDX, XRD, MIP), test normati e analisi non invasive.	it_IT
dc.language.iso	eng	it_IT
dc.publisher	Università Ca' Foscari Venezia	it
dc.rights	© Laura Falchi, 2013	it_IT
dc.subject	Water repellents	it_IT
dc.subject	Stearates	it_IT
dc.subject	Siloxanes	it_IT
dc.subject	Mortars	it_IT
dc.subject	Restoration	it_IT
dc.title	Study of innovative water repellent systems for the preservation and restoration of artificial stone materials	it_IT
dc.title.alternative	Studio di nuovi sistemi idrorepellenti per il risanamento e il recupero di materiali lapidei artificiali	it_IT
dc.type	Doctoral Thesis	en
dc.degree.name	Scienze chimiche	it_IT
dc.degree.level	Dottorato di ricerca	it
dc.degree.grantor	Scuola di dottorato in Scienze e tecnologie (SDST)	it_IT
dc.description.academicyear	2013	it_IT
dc.description.cycle	26	it_IT
dc.degree.coordinator	Selva, Maurizio
dc.location.shelfmark	D001303	it
dc.location	Venezia, Archivio Università Ca' Foscari, Tesi Dottorato	it
dc.rights.accessrights	openAccess	it_IT
dc.thesis.matricno	955842	it_IT
dc.format.pagenumber	XIV, 250 p. : ill.	it_IT
dc.subject.miur	CHIM/12 CHIMICA DELL'AMBIENTE E DEI BENI CULTURALI	it_IT
dc.description.tableofcontent	Abstract I Sommario II Acknowledgments V Table of contents VII Glossary XI Chapter 1. Introduction 1 1.1. Background 1 1.2. Objective and Innovations 2 1.3. Synopsis of the thesis 3 1.4. State of the Art 4 1.4.1. Ancient and modern hydraulic binders 4 1.4.1.1. Hydraulic binders in the Conservation of Cultural Heritage 5 1.4.2. Chemical and physical aspects of hydraulic binders 6 1.4.2.1. Cement 7 1.4.2.2. Natural hydraulic lime 11 1.4.2.3. Pozzolana-lime 12 1.4.3. Deterioration of porous building materials 13 1.4.3.1. Moisture in porous mortars and stones 14 1.4.3.2. Moisture and salts in mortars and stones 16 1.4.3.3. Salty masonries: the case of Venice 18 1.4.4. Water repellent systems 20 1.4.4.1. Metal soaps 21 1.4.4.2. Silane /siloxanes 24 1.4.4.3. Organic polymers 28 Chapter 2. Research strategy 31 2.1. Starting materials 33 2.1.1.Binder systems 33 2.1.2.Aggregates 33 2.1.3.Water-repellent admixtures 33 2.2. Casting procedure and exposure condition 34 2.2.1.Water-repellent binder pastes 35 2.2.2.Water-repellent mortars 37 2.1.1.Exposure/weathering condition of water-repellent mortars 37 2.1.1.1. Artificial ageing conditions 37 2.1.1.2. Resistance to salt crystallization 37 2.1.2.Water-repellent mortars on salty masonry 38 2.2. Investigations techniques 40 2.2.1.X-ray fluorescence analysis 40 2.2.2.X-ray diffraction 40 2.2.3.Differential scanning calorimetry/ Thermogravimetric Analysis 40 2.2.4.Fourier Transform Infrared Spectroscopy 40 2.2.5.Optical microscopy (OM) 41 2.2.6.Scanning electron microscopy coupled with energy dispersive X-ray probe 41 2.2.7.Isothermal calorimetry 41 2.2.8.BET analysis 41 2.2.9.Colorimetric measurements 41 2.2.10Consistence and density of the fresh mortar mixtures 42 2.2.11.Density, microstructure (MIP) and ultrasonic measurements (US) 42 2.2.12.Mechanical properties of the mortars 43 2.2.13.Capillary water absorption 44 2.2.14.Contact angle measurements 44 2.2.15.Water vapour permeability 45 2.2.16.Conductivity measurements 45 2.2.17.Mid IR Infrared Thermography 45 Chapter 3. Results 47 3.1. Analysis and Characteristics of the Starting Materials 47 3.1.1.Limestone cement 47 3.1.2.Natural hydraulic lime 48 3.1.3.Pozzolana-Lime 48 3.1.4.Aggregates 49 3.1.5.Water repellent admixtures 54 3.1.5.1. Silanes/siloxanes 54 3.1.5.2. Stearates 55 3.1.5.3. Organic polymer 56 3.1.6.Weathering of water repellent admixtures 60 3.1.6.1. Water-repellents in water 60 3.1.6.2. Water-repellents in Ca(OH)2 saturated solution 60 3.1.6.3. Water-repellents in oven at 55°C 61 3.2 Study of the hydration of binder pastes 63 3.2.1 Limestone cement pastes with water-repellents 64 3.2.1.1 XRD Study of limestone cement pastes with water repellents during the hydration 64 3.2.1.2 TG-DSC Study of limestone cement pastes 67 3.2.1.3 FT-IR study of limestone cement pastes 70 3.2.1.4 SEM observations of limestone cement pastes 73 3.2.1.5 Isocalorimetric measurements 77 3.2.2Natural hydraulic lime pastes with water-repellents 78 3.2.2.1 XRD Study of natural hydraulic lime pastes 78 3.2.2.2 TG-DSC Study of natural hydraulic lime pastes 80 3.2.2.3 FT-IR study of natural hydraulic lime pastes 84 3.2.2.4 SEM observations of natural hydraulic lime pastes 86 3.2.3Hydraulic pozzolana-lime pastes with water-repellents 89 3.2.3.1 XRD Study of hydraulic pozzolana-lime pastes 89 3.2.3.2 TG-DSC Study of hydraulic pozzolana- lime pastes 91 3.2.3.3 FT-IR study of hydraulic pozzolana- lime pastes 95 3.2.3.4 SEM observations of pozzolana-lime pastes 97 3.2.3.5 Isocalorimetric measurements 101 3.2.4Distribution of the water repellents inside the binder matrixes 102 3.3 Chemical and physical properties of Mortars with water- repellent admixtures 106 3.3.1 Limestone cement mortars with water-repellents 106 3.3.1.1 Mix design, composition and properties of fresh mortars 106 3.3.1.2 Properties of 28 days aged limestone cement hardened mortars 107 3.3.2 Natural hydraulic lime mortars with water repellents 120 3.3.2.1 Mix design, composition and properties of fresh mortars 120 3.3.2.2 Properties of 28 days aged natural hydraulic lime mortars 120 3.3.3Pozzolana-lime mortars with water repellents 130 3.3.3.1 Mix design, composition and properties of fresh mortars 130 3.3.3.2 Properties of 28 days aged natural hydraulic lime mortars 130 3.4 Artificial weathering of mortar specimens 140 3.4.1.Artificial weathering of limestone cement mortars 140 3.4.1. Artificial weathering of natural hydraulic lime mortars 144 3.4.2.Artificial weathering of pozzolana-lime mortars 147 3.5 Resistance to salt crystallization 152 3.5.1.Salt weathering of water-repellent limestone cement mortars 153 3.5.1.1. Resistance to salt crystallization and external appearance of water repellent limestone cement mortars after the exposure 153 3.5.1.2. Composition, microstructure and salt distribution in limestone cement mortars after the exposure 158 3.5.1.3. Capillary water absorption and compressive strength after the exposure 161 3.5.2.Salt weathering of water-repellent natural-hydraulic-lime mortars 163 3.5.2.1. Resistance to salt crystallization and external appearance of natural hydraulic lime mortars after the exposure 163 3.5.2.2. Composition, microstructure and salt distribution in natural hydraulic lime mortars after the exposure 168 3.5.2.3. Capillary water absorption and compressive strength after the exposure 172 3.5.3.Salt weathering of water-repellent pozzolana-lime mortars 173 3.5.3.1. Resistance to salt crystallization and external appearance of pozzolana-lime mortars after the exposure 173 3.5.3.2. Composition, microstructure and salt distribution in pozzolana-lime mortars after the exposure 178 3.5.3.3. Capillary water absorption and compressive strength after the exposure 180 3.5.4.XRD analysis of different mortar mixes after the salt weathering 181 3.6. Water-repellent mortars applied on salty masonry 184 3.6.1. Mortar mixtures 184 3.6.2.Observation during the capillary rise of salt solutions 185 3.6.3.Chemical-physical properties of the mortars before and after one moths of exposure to capillary rise of salt solution 190 3.6.3.1. Chemical composition 190 3.6.3.2. Mechanical strength, capillary water absorption, microstructure and salt distribution 191 Chapter 4. Discussion, conclusions and perspectives 201 4.1 Discussing the results of Chapter 3.2: 202 4.1.1Hydration reactions of Limestone Cement Pastes without and with water-repellents 202 4.1.2Hydration reactions in natural hydraulic lime pastes without and with water-repellents 206 4.1.3Hydration reactions of pozzolana-lime pastes without and with water-repellents 207 4.2 Discussing the results of Chapter 3.3 209 4.3 Discussing the results of Chapter 3.4 214 4.4 Discussing the results of Chapter 3.5 215 4.5 Discussing the results of Chapter 3.6 217 4.6 Correlation of physical properties of water-repellent mortars: a multivariate approach 220 4.6.1 PCA analysis of water-repellent mortars 220 4.6.2 PCA analysis of water-repellent mortars before and after the exposure to the action of saline solutions 225 4.7 Conclusions 230 4.7.1 Main Results 231 4.8 Perspectives 232 References 233 Appendix 1 Materials information 247 Estratto per riassunto della tesi di dottorato	it_IT
dc.identifier.bibliographiccitation	Falchi Laura. "Study of innovative water repellent systems for the preservation and restoration of artificial stone materials", Ca' Foscari University of Venice, Doctoral Thesis, 26. ciclo, 2013	it_IT