Ion Evolution in Pore Solution of Alkali-activated Slag System and Its Effect on Passivation Behaviour of Steel Bars
Year: 2024
Type: article
Abstract: The passivation of steel bars in concrete is determined by the characteristics of the concrete pore solution. However, ion evolution in the pore solution of alkali-activated slag/limestone powder (AAS/L) systems is not yet well known. Therefore, in this study, ion evolution in real and simulated pore solutions of alkali-activated slag/limestone powder mortars is investigated using high-pressure and solid-liquid extraction methods. The study focuses on investigating the passivation behaviour of steel bars when exposed to the simulated pore solution. The results demonstrate that the contents of Ca, Na, Al, Si, and S2O32- first increase and then decrease with time, whereas the contents of K and SO42- consistently increase. Among the simulated pore solutions, the one with a solid-liquid ratio of 1 : 1 and an age of 14 days closely resembles the actual pore solution. In addition, the presence of a high S content resulting from the dissolution of S in the slag inhibits the passivation process of the steel bars in the simulated pore solution of AAS. However, the passivation film of the steel bars formed in the simulated AASL pore solution is strengthened by the addition of the limestone powder.
DOI: 10.3151/jact.22.499
Authors: Zhantao Du, Zuquan Jin, Bo Pang, Shicai Li, Chencui Wang
Institution: Qingdao University of Technology
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
Awards: G255786004, G2796426470, G4499835394
OpenAlex ID: W4401872439