Consolidação de revestimento de argamassa à base de cal: desenvolvimento de argamassa injetável adaptada às paredes escaioladas de prédios históricos de Pelotas/RS.

Abstract

This thesis presents the development process of injecting mortar for restoration of lime mortar coatings of finishing plaster (escaiolas) of historical buildings of Pelotas. The review provides general information about the lime mortars used in coating and on the finishes in plaster called escaiola, relatively common in historical buildings of Pelotas. The review also discusses the pathology and how to restore these coatings. Then it treats specifically about the injectable mortars used to restore the coating system when the grip is lost; the performance parameters for these mortar; and the dosage method that can be used for their formulation. The experimental procedure was divided into three phases. During the first phase, original samples of mortars used for leveling coatings for plaster were studied; Then a similar to the original mortar was developed to obtain performance parameters to be achieved by the injection mortar to be developed; in the second phase 27 mortar injectable formulations consisting of hydrated lime and sand (diameter of 0.3 mm greater) with additions of rice hull silica were tested; in the third phase sought to enhance the mortar selected in the previous phase by the use of superplasticizer and reducing water. The results showed that the developed injectable mortars are partially compatible with the original substrate having high capillarity coefficients. The use of superplasticizer to a limit of 0.9% of the weight of hydrated lime was appropriate since it contributes to the reduction of capillarity coefficient without substantially altering other characteristics of the injection mortar.