Characterisation of Primary and Secondary Stone Bioreceptivity

Stone bioreceptivity is its ability to support the colonisation and growth of microorganisms. Primary bioreceptivity is the initial potential for biological colonisation of a sound or freshly cut stone, while secondary bioreceptivity is the potential for biological colonisation of stone weathered by environmental factors and/or colonisers. This research report presents the results from the pilot phase of a research project to address knowledge gaps in stone bioreceptivity. The pilot phase developed a protocol for determining primary and secondary stone bioreceptivity. It devised a repeatable protocol to measure the characteristics that influence bioreceptivity on a range of different stone types, enabling comparison of colonisation levels. Results from these tests were used to calculate a bioreceptivity index value. Bioreceptivity indices can be used to compare greening rates of different types of stone. They will help specifiers select replacement stones that share similar bioreceptivity properties to pre-existing stones. The laboratory-based model for measuring bioreceptivity will be used to test biocide alternatives used for treating English limestone stonework in the main phase of the research.