Theoretical Study On The Applicability Of Calcium Formate And Triethanolamine To White Cement

In recent decades,with the implementation of various policy guidelines,the cement art industry has received significant attention.White cement,known for its whiteness,has been widely used in creating various beautiful art pieces by combining it with different dyes.Consequently,the demand for white cement has been on the rise.Despite the inherent advantage of white cement in early strength performance,it still falls short of meeting the strength requirements for demolding within the desired time frame in some practical applications.Although previous studies have extensively investigated the early strength performance of organic early strength agents on ordinary Portland cement,research on the influence mechanisms of different types of organic early strength agents on the hydration process and performance development of white cement remains insufficient.In this experiment,calcium formate（CF）and triethanolamine（TEA）were selected to study their effects on white cement.By conducting macroscopic performance tests,microscopic structure characterization and analysis,and combining them with hydration kinetics calculations,we aim to explore the early strength mechanisms of CF and TEA on white cement for the first time.There have been numerous studies on the effects of CF and TEA on Portland cement,but limited research has been conducted on white cement.In this experiment,we selected both CF and TEA as additives to investigate their applicability and enhance the theoretical guidance for organic early strength agents in white cement.CF has significantly different effects on the early properties and hydration of white cement compared to Portland cement.According to flowability tests,CF has no significant impact on the flowability of white cement but improves the flowability of Portland cement.Setting time tests show that CF has varied effects on the setting time of white cement,initially prolonging it and later shortening it,while shortening the setting time of Portland cement.In terms of early mechanical performance,CF exhibits an opposite trend between white cement and Portland cement.Research on early hydration reveals distinct differences in heat release and kinetics between CF-added white cement and Portland cement.CF delays the hydration of white cement but promotes more thorough hydration of Portland cement.XRD and FTIR tests indicate that CF does not alter the hydration products of both types of cement.SEM and MIP tests demonstrate that CF does not optimize the porosity of white cement and even shows visible loose structures in SEM images,while it densifies the structure and optimizes the pore size of Portland cement.ICP tests reveal that CF reduces the p H and OH^-concentration of both white and Portland cement,with similar trends observed for the concentrations of Ca²⁺,Al³⁺,Si⁴⁺,and Na⁺.In contrast,trace amounts of TEA significantly affect the early properties and hydration of white cement and Portland cement.Flowability tests show that TEA enhances the flowability of white cement but has varied effects on the flowability of Portland cement.Setting time tests indicate that TEA prolongs the setting time of white cement but has inconsistent effects on the setting time of Portland cement.Early mechanical performance tests reveal an opposite impact of trace TEA on the strength of white cement and Portland cement.Heat release and hydration kinetics studies demonstrate that TEA has an insignificant effect on the hydration of white cement but greatly enhances the third peak of heat release during the hydration of Portland cement,promoting more thorough hydration.XRD and FTIR tests confirm the involvement of TEA in the chemical reactions of both cement types without altering the types of reaction products.SEM and MIP tests show that TEA addition leads to a loose structure in white cement with visible voids,while 0.02%TEA optimizes the pore structure of Portland cement,making it denser.ICP tests reveal that TEA increases the p H and OH^-concentration of both cements,with 0.01%TEA significantly affecting the ion concentration in the liquid phase of white cement compared to 0.1%,and 0.1%TEA significantly affecting the ion concentration in the liquid phase of Portland cement compared to 0.01%.