Impact of gamma-ray irradiation on hardened white Portland cement pastes exposed to atmosphere. (June 2018)

• Record Type: Journal Article
• Authors: Maruyama, Ippei; Ishikawa, Shunsuke; Yasukouchi, Junichi; Sawada, Shohei; Kurihara, Ryo; Takizawa, Masayuki; Kontani, Osamu
• Is Part Of: Cement and concrete research. Volume 108(2018)
• Page Start: 59
• Page End: 71
• Publication Date: 2018-06
• Subjects: Gamma-ray irradiation -- Carbonation (C) -- Calcium–silicate–hydrate (C–S–H) (B) -- Physical properties (C); Cement -- Periodicals; Cement -- Research -- Periodicals; Concrete -- Periodicals; Concrete -- Research -- Periodicals; Ciment -- Périodiques; Béton -- Périodiques; Cement; Concrete; Periodicals; 620.135
• DOI: 10.1016/j.cemconres.2018.03.005
• Languages: English
• ISSNs: 0008-8846

Abstract

Abstract: Samples of matured hardened cement paste were exposed to an environment with gamma-ray irradiation, which induces a natural carbonation process. After a dose of approximately 5 × 10 4 kGy, the physical properties, microstructure, and phase composition of the irradiated hardened cement paste samples are compared with those of reference samples exposed to an identical environment without gamma-ray irradiation. Experiments confirm that aragonite and vaterite are preferentially formed under irradiation and that the bending strength is dramatically increased after gamma-ray irradiation. Based on field-emission scanning electron microscopy observations, X-ray scattering profiles, and water vapor sorption isotherm data, it is concluded that vaterite formed on C–S–H plays a role in strengthening the structure of C–S–H via pseudomorphs.