Experimental study on the performance of lime-based grouts used in consolidating historic masonries

摘要

Grouting is an old and widely used irreversible technique for consolidating historic masonries. However, since some undesirable secondary problems appeared in historic masonries after interventions with cement-based grouts, alternative mixtures have been also studied. In the paper, traditional binders such as hydrated lime, pozzolan, clay and brick dust have been used as constituents of grout mixtures, which were modified with cement and admixtures. Grouts' performance was tested in fresh (Fluidity, Penetrability, Volume Stability) and hardened state (Dynamic Modulus of Elasticity, Flexural and Compressive strength). Results showed clearly that grouts based on traditional binders present adequate performance and strength, for filling discontinuities and consolidating masonry structure. Proper combinations of "soft'' binders, aided by small proportions of cement and admixtures developed 28-d and 90-d strength of 2.5 and 5 MPa respectively.