Recently, there has been renewed interest in the use of hydraulic lime mortars. They are attractive not only to the modern architect, but also have extensive use in the restoration and protection of historic architecture. This has led to a demand for an increasing quantity of research into these materials as much current knowledge is drawn from anecdotal accounts rather than validated scientific research. In this thesis the link between the mineralogy and physico-chemical properties of a series of hydraulic limes was investigated; the series being chosen to represent the various commercial grades, ranging from feebly to eminently hydraulic (class 2 to 5 MPa according to BS EN 459-1). A preliminary study of as received samples indicated key differences in the physical (e.g particle size, surface area profiles) and chemical (mineralogy) of samples from the five selected grades. Further analysis of these limes using a range of complementary physical and solid-state techniques on both mortars and pastes of hydraulic limes, have shown for the initial strengths, a good link between the bulk density I water demand of hydraulic limes. There was also strong evidence of a link between the consumption of belite (through hydration) and the development of strength through the deposition of hydration products to form a complex crystalline matrix. This influence was seen to reduce the porosity which had a critical influence on obtained strengths of both the mortars and hydraulic lime pastes. The durability of the hydraulic limes was investigated using freeze thaw testing. An increased resistance to frost damage was observed as the grade of the hydraulic lime increased, and with the ageing of the hydraulic lime mortars. The observed frost resistance was strongly influenced by the hydraulicity of the materials thereby providing further evidence for the impact of both qualitative and quantitative differences in mineralogy on hydraulic performance.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:522663 |
| Date | January 2004 |
| Creators | Scott, Catherine Anne |
| Publisher | Keele University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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