GUAN X M, ZHANG G L, HE F Q, et al.Study on the formation and stability of Friedel’s salt in cement-based materials in chloride environment[J].Journal of Henan Polytechnic University(Natural Science) ,2023,42(5):176-182.

doi:10.16186/j.cnki.1673-9787.2022010068

Received:2022/01/22

Revised:2022/05/09

Published:2023/09/25

Study on the formation and stability of Friedel’s salt in cement-based materials in chloride environment

GUAN Xuemao1, ZHANG Gaolong1, HE Fuqiang2, ZHOU Jin2

1.School of Materials Science and Engineering，Henan Polytechnic University，Jiaozuo  454000，Henan，China;2.School of Civil Engineering and Architecture，Xiamen University of Technology，Xiamen  361000，Fujian，China

Abstract:In order to study the formation law of Friedel’s salt in cement-based materials and its stability in chloride environment，by changing the water-cement ratio of specimen，the concentration of sodium chloride and the pH of the soaking solution，the change of Friedel’s salt content was tested by X-ray diffraction，thermal analysis，and ion chromatography.The formation of Friedel’s salt under different conditions，the effects of chloride ion concentration and pH on the stability of Friedel’s salt were analyzed.The results showed that：large water-cement ratio specimens had a higher degree of hydration，and more C₄AF hydration in the clinker provided the aluminum phase to adsorb chloride ions to form Friedel’s salt.Friedel’s salt could exist stably at pH≥12； when the pH value increased to 13.5，the ettringite dissolved in the hydration products，leading to more Friedel’s salt formation.When the chloride concentration of the environmental solution decreased，Friedel’s salt dissolved，but increasing the pH value of the solution could inhibit the dissolution of Friedel’s salt.

Key words:cement-based material;Friedel’s salt;chloride ion concentration;Friedel’s salt stability;pH

氯盐环境下水泥基材料中Fr...s盐的生成规律与稳定性研究_管学茂.pdf