On the development of unmodified mud grouts for repairing earth constructions: rheology, strength and adhesion

摘要

The conservation and rehabilitation of several sites of cultural heritage and of the large housing stock built from earth requires the development of techniques and materials compatible with this kind of construction. Grout injection is one repair solution which has been put forward over the last few years, whereas there is preference for employing grouts that incorporate earth in their composition. However, knowledge of such grouts is still very limited and requires further research. The experimental program discussed in this paper contributes to the comprehension of the influence of the composition of an unmodified mud grout, namely regarding its fresh-state rheology, hardened-state strength and adhesion. In general, the results obtained showed that the rheological behaviour of a mud grout greatly depends on the colloid behaviour of the clay fraction, and that the addition of a deflocculant and modification of the clay content (with a silt size material) is required to obtain grouts with adequate solid fractions.