Optimisation of flow behaviour and stability of superplasticized fresh hydraulic lime grouts through design of experiments

One of the techniques of old masonry consolidation is the injection of grouts. For a successful injection it is necessary to ensure an adequate flow of the grout inside the porous media, for which it becomes essential to control the grout rheological behaviour and stability. This paper analyses the influence of grout mixing procedures on rheological behaviour, water retention and stability of hydraulic lime grouts with superplasticizer. This research has particular relevance due to lack of information about the use of superplasticizers in hydraulic lime grouts, compared to the amount of information that exists in the case of Portland cement based mixtures. The research showed that fresh grout behaviour can be improved using an appropriate mixing procedure, optimised with the Taguchi method.