Inorganic polymers were synthesised using metakaolin and cotton shell ash as activator. In this way, the negative environmental impact of sodium or potassium silicate solutions as alkaline activators can be eliminated. Phase transformations investigated using FTIR suggested the formation of inorganic polymers through the shift of the most intense band from 1031 cm −1 in metakaolin to around 973 cm −1 in the final product and the absence of the band at 789 cm −1 in the latter. XRD results revealed the presence of kalsilite and zeolite K-F, which appear as hexagonal and elongated crystals in SEM. A maximum compressive strength of 36.7 MPa was obtained. Compressive strength values increased with increasing K/Al ratios and with the reduction of pore densities due to the formation of the amorphous inorganic polymer matrix as observed on the SEM micrographs. Cotton shell ash can thus be used as an alternative activator.

Original languageEnglish
Pages (from-to)1011-1022
Number of pages12
JournalConstruction and Building Materials
Publication statusPublished - 10 Dec 2018

    Research areas

  • Calorimetry, Compressive strength, Cotton shell ash, FTIR, Inorganic polymer, Metakaolin, SEM, XRD

ID: 43623241