Investigation of Deicing Salt Solution in Process of Calcium Oxychloride Formation in Cement Paste

Abstract: This research aims to investigate the formation of Calcium Oxychloride (CAOXY) in concrete pavement
joints resulting from the reaction between Calcium Hydroxide (Ca(OH)₂) in cement paste matrix and
chloride ions (Cl^2- ) from deicing salts [e.g., Calcium Chloride (CaCl₂)]. CAOXY formation is a common
problem in concrete pavements located in midwestern parts of the US, where deicers are frequently used,
causing joint deterioration. While previous studies have investigated the effect of CAOXY on pavements
and some of the parameters involved in its formation, this research focuses on acquiring better
understanding through investigating the combined effects of relevant parameters, including water to
cementitious ratio (W/CM), salt solution concentration, age, and temperature on CAOXY formation,
which facilitates developing effective solutions for mitigating joint deterioration The primary goal is to
develop an energy-based model for this reaction considering the most influential parameters such as
temperature and salt concentration. Visual observation and analysis, in addition to Thermogravimetric
Analysis (TGA) tests, were carried out to achieve this goal. Results reveal that temperature is a critical
parameter other than salt concentration that causes deleterious formation of CAOXY, leading to joint
deterioration in concrete pavement. The findings of this study is expected to be useful for developing
strategies to reduce the CAOXY formation and prevent the deterioration of concrete pavement joints,
especially in regions where deicers are frequently used.