Next Generation Lime Based Mortars

Lime based mortars have been used in the construction industry for centuries and are still used today, most notably in the conservation sector for the preservation of historic assets. Lime mortar provides a method of binding building blocks whilst accommodating movement and providing improved breathability over more recent cement based mortars. Whilst the practical properties and applications of the material are reasonably well understood by skilled craftsmen, the introduction of modern testing equipment has allowed for and enhanced understanding of the materials and the effect of production methods on mortar characteristics.
This PhD project will develop the understanding of how the manufacturing process, composition and properties influence the behaviour of lime based mortars with the surrounding medium in their built environment. The following objectives have been identified to achieve this aim, they are:
Undertake a literature review of microstructure - macrostructure property relationships in lime mortars
Characterise a range of stones/bricks to allow the behaviour of lime mortars when used in masonry to be assessed
Produce a representative range of lime based mortars including hot mix lime mortars
Characterise the physical and chemical properties of the mortars produced using techniques such as dynamic vapour sorption, rheometers, X-ray diffraction, FTIR spectroscopy, electron microscopy, Raman spectroscopy and mercury intrusion porosimetry
Evaluate the interactions between lime mortar and masonry through lab based experiments
Critically asses the mortars with respect to their properties in the built environment
Generate technical recommendations for existing lime based mortar mixes based on the results of characterisation tests
Educate conservation professionals on the use of mortar mixes in the built environment
The project will focus on (but not limited to) lime mortar mixes for use in the historic built environment. Mortars in the conservation industry must be compatible for use in the structure by possessing key properties including breathability and adequate, but not excessive, strength. It is new and modern equipment that enables the mortar properties to be better understood with this project which ultimately will increase the knowledge and understanding of existing lime based mortar mixes in their environment.