Injection Grouts for the Re-Attachment of Architectural Surfaces with Historic Value – Measures to Improve the Properties of Hydrated Lime Grouts in Slovenia

ABSTRACTIn the described studies with the aim of optimizing hydrated lime grout composition, the first measure was to reduce the water content of the grout using a highly efficient polycarboxylate ether-based superplasticizer, whereas the second measure was to increase the content of the inert limestone filler with an adequate grain size distribution. In this way, an attempt was made to achieve the best possible volume stability and strength properties of the hydrated lime grout, while continuing to fulfill the other necessary requirements regarding non-structural grouting works which are reported in the literature.The results of the tests showed that a non-structural grout consisting of 1 volume part of hydrated lime CL 90-S and 3 volume parts of inert limestone filler, with 0.5% of the polycarboxylate ether based superplasticizer, fulfilled most of the established requirements, so that it is thus potentially suitable for re-attachment interventions on architectural surfaces.