Preparation and rheological performance analysis of volcanic ash and metakaolin based geopolymer grouting materials.

This study investigated the possibility of using volcanic ash and metakaolin (MK) to prepare road grouting materials. The effects of different contents of MK and water glass(WG) on the mechanical properties, setting time and rheological properties of the materials were investigated separately. The materials science testing methods were also used to observe the reaction mechanism of the geopolymer products. The test results showed that the compressive strength increased with the content of MK and SS. The average flow curve of geopolymer grouts fitted the Bingham model. The multilayer lamellar microstructure of MK increases the rheological parameters of the pastes. While the WG suspends VA and MK particles, which reduces the rheological parameters of the pastes. It can be concluded from the results of microscopic experiments that the MK reduces side reactions as well as sodium by-products, while WG produces more silica-aluminate filling the voids which enhance the compressive strength. [ABSTRACT FROM AUTHOR]