Influence Mechanism of Curing Regime on Strength of Barite Radiation Shielding Concrete

Abstract

Abstract: In order to further improve the strength of radiation shielding concrete, this paper investigates the strength of barite radiation shielding concrete under different curing regimes by setting up four curing regimes: standard curing, steam curing, combined curing 1 (3 d steam curing +25 d standard curing) and combined curing 2 (7 d steam curing +21 d standard curing). The effects of different curing regimes on the radiation shielding concrete hydration products, interfacial transition zone (ITZ), fiber and steel shot bonding property were investigated by scanning electron microscope (SEM). The test results show that both steam curing and combined curing enhance the strength of radiation shielding concrete compared to standard curing, in which the 28 d compressive strength and splitting tensile strength of steam curing improve the most compared with standard curing, which increase 12.7% and 9.5%, respectively, and both high temperature and high humidity curing environments stimulate the volcanic ash activity of silica fume and promote Ca(OH)₂ to participate in the secondary hydration to generate honeycomb-like C-S-H gel, and the formation of needle-like or columnar calcium alumina (AFt), making the microstructure more dense; at the same time, it will enhance the stability of the internal ITZ of radiation shielding concrete and reduce the gaps; and the fibers and steel shot with the substrate bonding property is better, and better tensile and pull-out resistance, of which steam curing is more obvious. This paper provides a new reference for the research of radiation shielding concrete.

Key words: radiation shielding concrete, barite, curing regime, microstructure, strength, bonding property

CLC Number:

TU596

SI Pengchao, XUE Kaixi, ZHOU Ziqin, WANG Shengfu, HU Yanxiang, OUYANG Zhihui. Influence Mechanism of Curing Regime on Strength of Barite Radiation Shielding Concrete[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2024, 43(11): 3996-4003.

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