Microscopic study of the concrete / Geopolymer coating interface

Abstract

This paper presents an experimental study at microscopic level of the interface between geopolymer coating and concrete. Seven varieties of prepared geopolymer-based materials (GbM) have been applied to industrially prepared concrete bodies. The differences in the composition of the layers as well as in the application type (dry/wet surface) can cause ion migration from the viscose GbM to the solid concrete and reversely from the concrete to the formatted netting of the hardened geopolymer. The interlayer between the geopolymer coating layers and the hardened concrete has been investigated by two microscopic methods: optical and scanning electronic microscope equipped with SEM/EDAX analyses. The results have shown that the coating layers considerably reduce calcium ion penetration into the GbM chained structures.