The mechanical properties and electrochemical behavior of cement paste containing nano-MgO at different curing temperature

• Published in: Construction & building materials 2018-03, Vol.164, p.663-671
• Main Authors: Song, Shiqi, Jiang, Linhua, Jiang, Shaobo, Yan, Xiancui, Xu, Ning
• Format: Article
• Language: English
• Subjects: Cement paste; Cements (Building materials); Chemical properties; Curing agents; Curing temperature; Electrochemical impedance spectroscopy; Electrochemical reactions; Mechanical properties; Nano-MgO
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2018.01.011

•Nano-MgO was used as admixture to improve the mechanical properties and electrochemical behavior.•The flexural and compressive strength of cement paste containing nano-MgO cured at 60 °C was higher than that of 20 °C.•Hydration feature of cement paste containing nano-MgO cured at different temperature was studied by EIS test.•A suitable electrochemical equivalent model was applied to fit the measured electrochemical impedance data of cement paste. The purpose of the research work is to investigate the mechanical properties and electrochemical behavior of cement paste containing nano-MgO (NM) which cured at different temperature. The measurements of flexural strength, compressive strength and electrochemical impedance spectroscopy were conducted. A suitable electrochemical equivalent mode was applied to fit the measured electrochemical impedance data (Nyquist curve), therefore the electrochemical property for cement paste containing NM can be quantitatively obtained. Results demonstrated that the flexural and compressive strength gradually increased with the increasing of NM contents ranged from 0 wt% to 9 wt% in cement paste. Moreover, the strength of the cement paste containing NM was increased gradually when the curing temperature rising from 20 °C to 60 °C. In addition, with the increasing of NM content and the rising of curing temperature, the electrolyte solution resistance Rs and the ion transport processes resistance Rct1 showed increasing tendency. And XRD, TG-DSC and SEM were used to characterize the phases, mass/heat changes and microstructure of the hardened cement pastes, which provided some evidence on these research findings.