25 January 2010

Lime-based restoration mortars (2009)

Title: The effect of linseed oil on the properties of lime-based restoration mortars
Author: Eva Čechová
University: University of Bologna (Italy)
Year: 2009
Type of document: PhD thesis
Download: http://amsdottorato.cib.unibo.it/... (pdf, 4.9 Mb)

The traditional lime mortar is composed of hydrated lime, sand and water. Besides these constituents it may also contain additives aiming to modify fresh mortar´s properties and/or to improve hardened mortar´s strength and durability. Already in the first civilizations various additives were used to enhance mortar´s quality, among the organic additives, linseed oil was one of the most common. From literature we know that it was used already in Roman period to reduce water permeability of a mortar, but the mechanism and the technology, e.g. effects of different dosages, are not clearly explained. There are only few works studying the effect of oil experimentally. Knowing the function of oil in historical mortars is important for designing a new compatible repair mortar. Moreover, linseed oil addition could increase the sometimes insufficient durability of lime-based mortars used for reparation and it could be a natural alternative to synthetic additives. [...]

Table of contents (compact version):

1. Introduction

2. Theory
2.1 Definition of Mortar
2.2 Mortar Composition
2.3 Types of Mortar
2.4 Deterioration of Mortars
2.5 Natural Polymers as Mortar Admixtures

3. Experimental Part
3.1. Used Materials
3.2 Experimental Methods

4. Results
4.1. Basic Characteristics of Materials Used
4.2. Setting Time Determination
4.3. Composition and Properties of Fresh Mortars
4.4. Properties of Hardened Mortar
4.5. Observation of Oil in Mortar Strucutre
4.6. Studying of chemical Changes of Oil in mortar and Oil Aging

5. Discussion
5.1. The effect of Linseed Oil on the Properties of Fresh Mortars
5.2. The effect of Linseed Oil on the Properties of Hardened Mortars

6. Conclusions
6.1. The Effect of the Addition of Linseed Oil on Mortars Properties and the Mechanisms of its Operation
6.2. Suggestions for further Research

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