Design and evaluation of hydraulic lime grouts for the reattachment of lime plasters on earthen walls

Abstract

A laboratory and field testing programme for the formulation and evaluation of hydraulic grouts was developed for the reattachment of lime plasters on earthen (adobe) walls. Formulations utilizing kaolin, hydraulic lime, ceramic microspheres, and fine silica sand, with and without the addition of an acrylic emulsion, were prepared and evaluated in a three-stage testing programme. Standard tests were employed to measure injectability, viscosity, set time, shrinkage, weight, splitting/tensile strength, water vapour transmission rate, and adhesive bond strength. Grout microstructure was comparatively examined using scanning electron microscopy. Of the 18 grout formulations tested, only one mixture composed of (parts by weight) 1 part microspheres, 1 part sand, 2 parts hydraulic lime, 10% part acrylic emulsion was found to meet all the essential performance criteria established.