MOISTURE RESISTANCE OF EARTHEN COATINGS STABILIZED WITH GLYCEROL

Abstract

One of the fundamental components of earth architecture is its coatings because they protect structures from atmospheric and anthropic agents. However, due to the hygroscopic nature of the earth, the plasters are highly vulnerable to rain and groundwater absorption. To deal with these agents of decay, experts and artisans have tested with different stabilizing substances throughout history. This article reviews a series of experiments based on verifying the use of small glycerol fractions to increase the durability and resistance of the earth coatings. Glycerol is a byproduct of various industrial processes, such as the production of biodiesel. Recently, there has been a significant increase in its production, making it a viable resource to consolidate and protect both historical building components and contemporary buildings. We analyzed comparatively mortars of natural earth, and others stabilized with glycerol to verify the cohesiveness, quantity of water required, and drying time. Subsequently, we performed flat tests and plasters applied on walls to undergo capillary absorption conditions and rain impact. An increase in the cohesiveness of the mortars added with glycerol of 12%, decreases the amount of water required for the mixtures by 18% and the drying time rises by almost 7 hours. The stabilized specimens absorbed 26% less water by capillarity, and the exposed coatings to weather conditions maintain their integrity after eight months of staying outdoors. Earthen mortars that were enriched with small volumes of glycerol developed a highly positive response to these factors, which are the most likely to provoke the earth plasters and the structures they protect. It is possible to have a material that improves the mixtures of soil and is sustainable from an economic, ecological, and cultural point of view.