Incorporation of magnetite powder as a cement additive for improving thermal resistance and gamma-ray shielding properties of cement-based composites. (20th April 2019)

• Record Type: Journal Article
• Authors: Sikora, Pawel; Abd Elrahman, Mohamed; Horszczaruk, Elzbieta; Brzozowski, Piotr; Stephan, Dietmar
• Is Part Of: Construction & building materials. Volume 204(2019)
• Page Start: 113
• Page End: 121
• Publication Date: 2019-04-20
• Subjects: Waste magnetite powder -- Cement paste -- Heat treatment -- Thermal resistance -- Gamma-ray shielding; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2019.01.161
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: An evaluation of the use of waste magnetite powder (MP) as a cement replacement. Evaluation of thermal resistance and γ-ray shielding properties of cement pastes. Replacement of cement with MP improves compressive strength of unheated specimens. Addition of MP decrease mass loss, strength loss and crack propagation of specimens. MP addition improves γ-ray shielding properties of specimens at elevated temperature. Abstract: In this contribution, the effect of waste magnetite powder (MP), obtained from a rock crushing process, as an additive to cement pastes exposed to elevated temperature and gamma-ray radiation, is evaluated. Cement pastes with different magnetite powder to cement ratios, up to 50% by mass, and exposed to temperatures of 200 °C, 300 °C, 450 °C and 600 °C, were prepared. The thermal conductivity, mass loss, compressive strength and shielding efficiency against gamma-rays ( 137 Cs) of the specimens were determined and the results compared with theoretical values obtained according to the WinXCom program, at different energy levels. The results demonstrate that the addition of MP significantly increases paste density, thermal conductivity, as well as the specific heat of cement stone. Moreover, the inclusion of MP contributes to strength improvements in both heated and unheated states. Likewise, the presence of MP leads to a decrease in mass loss and surface cracking on exposure to high temperature. In conclusion, it is argued that the incorporation of MP results in a significant improvement in gamma-ray shielding properties, as compared to plain cement pastes.