Protection of Historical Buildings by Using New Chemical Techniques: Taking Nanjing as an Example

The Drum Tower, Office of the President and Zhan Yuan Garden were selected as examples to investigate the present existence status and corresponding effectiveness of protection measures (especially chemical aspects). A new strategy of using sol-gel technique hybrided with chitosan was pertinently brought forward. The application prospect is analyzed. Results show that most of the construction and component materials are not well-protected (damaged, weathered, corroded and withered), which weakens the overall structural stability and fire-proofing capability. Through good design, sol-gel products like silicon dioxide or titanium dioxide hybrided with chitosan can improve the performances of various material qualities used in historical buildings, such as anti-aging, insect-proofing, anti-bacterial, anti-corrosion and fire-proofing.