The identification of organic additives in traditional lime mortar

Organic-inorganic lime mortars were widely used in many ancient buildings due to their good performance in some fields (such as caking property, water repellency, weatherability, etc.). However, many ancient buildings and sites are suffering from various degrees of damage with the development of the economy and society and appropriate conservation and restoration are needed. The application of traditional construction materials, such as organic-inorganic lime mortars, attracts more and more attention in the conservation and restoration of ancient buildings in the recent years. So, the understanding of the components of original lime mortar which remained in ancient sites is of fundamental significance. In this work a set of analytical procedures to identify the organic additives in lime mortars by classical chemical analysis is proposed. The results show that using iodine-potassium iodide reagent, Benedict's reagent, reduction phenolphthalein reagent, Coomassie brilliant blue and sodium periodate oxidation glycerin acetyl acetone method could effectively detect a small amount of starch, reducing sugar, blood, protein and fatty acid ester that remained in ancient buildings’ lime mortars, respectively. These analytical methods are easy to operate with low detection limit, high accuracy and some other advantages.