Swelling deformation of compacted bentonite considering the effects of Na cations and OH anions. Issue 4 (October 2021)

• Record Type: Journal Article
• Authors: Liu, Li-Na; Gao, Wen-Sheng; Guan, Lei-Lei
• Is Part Of: IOP conference series. Volume 861:Issue 4(2021)
• Publication Date: 2021-10
• Subjects: Earth sciences -- Periodicals; Environmental sciences -- Congresses; Environmental sciences -- Periodicals; 550.5
• DOI: 10.1088/1755-1315/861/4/042115
• Languages: English
• ISSNs: 1755-1307

Abstract

Abstract: Compacted bentonite has become a viable candidate as suitable artificial barrier material for restricting the movement of high-level radionuclides released from the canister in the deep geological repository. However, this material itself is fragile mainly because it is sensitive to the complex chemical environment especially alkaline components. Based on the interaction mechanism of cations and anions, this paper is mainly focused on the analysis of swelling deformation characteristics of compacted bentonite. Laboratory test results are shown that the elevated Na cations concentration can inhibit both the primary and secondary expansion process in compacted bentonite. The elevated OH anions concentration can inhibit the primary expansion process of compacted bentonite and will promote the secondary expansion process. The effects of NaOH solution with different concentrations on the swelling strain present the interaction of Na cations and OH anions. The swelling deformation of compacted bentonite is not only affected by the concentration of solution but also may be related to ionic compositions.