No abstract

No abstract

The low environmental impact and high long-term performance of products are becoming imperative for the sustainable development of the construction industry. Alkali-activated materials (AAMs) are one of the available low-embodied-carbon alternatives to Portland cement (OPC). For their application in the marine environment or where de-icing salts are used, it is of utmost importance to demonstrate their equal or better performance compared to OPC. The aim of this study was to compare the corrosion behaviour of the steel in AAMs based on different regionally available by-products with the behaviour of the steel in OPC. The by-products used were fly ash, slag, silica fume, and iron-silica fines. The corrosion process of each system was monitored by the corrosion potential and polarisation resistance during exposure to tap water and chloride solution over a period of almost one year. Certain AAMs showed a higher resistance to chloride penetration compared to OPC, which was attributed to the smaller number of capillary pores and higher gel phase precipitation. The same corrosion resistance compared to OPC was achieved with alkali-activated fly ash and alkali-activated slag mortars. The stability of the systems in tap water and chloride solution was confirmed by the visual assessment of the steel surface at the end of the test period.

No abstract

Alkali-activated materials are a group of alternative binders based on aluminosilicate precursor and an alkali activator. Since precursors are mostly waste materials and by-products, AAMs are consideredto be a valid and more environmental-friendly alternative to Portland cement. Although the AAMs show good performance, there are not enough studies in the literature about their long-term durability performance related to chloride ingress and embedded steel corrosion. The issue of this paper is to highlight the main difference between OPC and the different types of AAMs, and to give a short introduction about the state of art of this embedded steel corrosion.