Enhanced mechanical properties and environmental erosion resistance with metakaolin in a kind of Chinese traditional Lime-based mortar

Abstract

The Leshan Giant Buddha, which is located in Sichuan province, China, is the world’s tallest cliff statues (71 m). Due to the deterioration of the sandstone, conservation works have been carried out in past decades, and lime-based mortars have been used to repair the buddha for several times. Chuihui is a type of cementitious material used for the conservation of the Leshan Giant Buddha in 2001, but it has exhibited some deterioration due to multiple factors. In this study, metakaolin was used to enhance the volume stability, mechanical properties and environmental erosion resistance of traditional Chuihui. The results of XRD, FT-IR and Raman analyses demonstrate that metakaolin reacts with Ca(OH)2 via pozzolanic reactions and the produced C-S-H bond improves the properties of Chuihui-Metakaolin (C-M) mortars. Additionally, the microstructure of mortars becomes more compact due to the formation of cross-linked microstructures.