Geopolymer and ordinary Portland cement interface analyzed by micro-Raman and SEM. Issue 7 (3rd July 2022)

• Record Type: Journal Article
• Authors: Cantarel, Vincent; Yamagishi, Isao
• Is Part Of: Journal of nuclear science and technology. Volume 59:Issue 7(2022)
• Page Start: 888
• Page End: 897
• Publication Date: 2022-07-03
• Subjects: Geopolymers -- cements -- interfaces -- micro-Raman -- SEM; Nuclear engineering -- Periodicals; Nuclear physics -- Periodicals; Nuclear energy -- Periodicals; 621.4805
• DOI: 10.1080/00223131.2021.2016510
• Languages: English
• ISSNs: 0022-3131

Abstract

ABSTRACT: Geopolymers are a class of material that could potentially be used for sealing and repair of damaged concrete structures. This application is important for both decommissioning activities and standard industrial applications. The purpose of this article is to investigate the interface between ordinary Portland cement and geopolymer. The surface microstructure of the cement is investigated by SEM, EDX, and micro-Raman after embedding in geopolymer or immersion in the activation solution of a geopolymer for various durations. It is found that immersion in the solution induces a dendritic carbonation profile into the cement structure following the CSH gel. On the contrary, embedding in the geopolymer creates a dense, impermeable interface with a thickness of a few micrometers. This interface is found to be dense and brittle and it decreases the permeability of the surface, preventing the penetration of silicates into the cement structure. However, this brittle interface is sensitive to dehydration and can rupture under intense drying. This phenomenon can be utilized to separate the geopolymer and cement but is concerning if the integrity of the material must be guaranteed under extreme conditions. Graphical abstract: uf0001