Stress induced dissolution and time-dependent deformation of portland cement paste. (5th November 2018)

• Record Type: Journal Article
• Authors: Moradian, Masoud; Ley, M. Tyler; Grasley, Zachary C.
• Is Part Of: Materials & design. Volume 157(2018)
• Page Start: 314
• Page End: 325
• Publication Date: 2018-11-05
• Subjects: X-ray Computed Tomography -- Microstructure evolution -- Cement Hydration -- Creep -- Dissolution; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2018.07.060
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: While the stress-induced dissolution of various minerals has gained attention as an important time-dependent deformation mechanism, this has only sparingly been investigated in portland cement systems. In this paper, X-ray Computed Tomography (XCT) is used to make direct observations of the microstructural evolution in cement paste samples under different levels of stress during their first 60 h of hydration. Stiffness and creep measurements are also made while imaging the changes in the microstructure. The results show that stress applied at ages between 24 h and 60 h caused an increase in stiffness, increase in early age creep, and a statistically higher amount of dissolution of individual particles near the point of load application. Graphical abstract: Unlabelled Image Highlights: In-situ observation made on cement paste suggested that the stress application changed the development of microstructure. The cement grains dissolved faster under stress. The accelerated reactions under load resulted in increase in stiffness and deformation of the samples.