Research on Water-Free Injection Grouts Using Sieved Soil and Micro-Lime

Abstract

For the in-situ conservation of architectural surfaces, grout injection is a widely used and approved technique, even though it is an irreversible intervention. The research presented in this article explores grouting using sieved soil and micro-lime dispersed in isopropanol for plaster reattachment on earthen support. The grout formulations have been evaluated in several laboratory tests and at mock-up’s that look at the workability of fresh grout and the performance of the cured grout. On-site tests provide additional information about applicability and the performance of the grout with weakened historic earthen substrates. The results indicate that the tested formulations with varying percentages of micro-lime show good flowability on absorbing substrates and tolerable shrinkage. Results both from flexural strength tests and microscopic investigation demonstrate that the water-free soil- lime grouts provide good bonding to both the substrate and delaminated plasters. Higher lime content results in higher mechanical strength, indicating the grouts potential to be developed into suitable conservation materials for both plaster reattachment and crack repair in the conservation of earthen architecture.