Developments in chemical and biological detection of organic additives in Chinese historic mortar: A review

Abstract

Mortar is the prevalent binding material in ancient construction, and its organic addition has been one of the hot topics for years. In the study of organic addition, historical literature can provide references for composition, while detection can examine and verify the accuracy of the historical records, complementing each other. Conventional detection techniques such as spectroscopy, chromatography, mass spectrometry, and optical microscopy have been used to detect organic components in the laboratory, but they may face challenges such as low organic content, and difficulty in completing quick batch detection on-site. Therefore, researchers from Zhejiang University Cultural Heritage Laboratory (ZJUL) developed chemical and biological detection techniques (CBT). These techniques offer advantages such as high sensitivity and specificity, strong interference resistance, and are suitable for rapid on-site batch detection. ZJU has applied CBT to over 500 samples, carefully selected from a collection of more than 1000 samples gathered across various regions of China, spanning a timeframe of over 4000 years. This study summarizes and analyze the characteristics of Chinese ancient mortar for the first time. Spatial, temporal and typological patterns were discussed. The findings suggest that mortar production techniques have been transmitted and refined across generations over millennia.