蒸养静停时间对标养水泥石氯离子固化性能的影响

采用吸附平衡方法研究了蒸养制度参数中静停时间对水泥石氯离子固化性能影响,讨论了蒸养结束后,该性能随后续标准养护时间变化特征.采用XRD和DTA分析水泥石水化产物物相变化特征与水泥石氯离子固化性能变化之间的关系.结果表明,蒸养对水泥石氯离子固化性能有较大的影响.水泥石中的固化态氯离子数量随着静停时间增加,先增加,后减少.当后续标养时间为28 d时,蒸养水泥石中的固化态氯离子数量要明显低于标养试样;但当后续标养时间达到90 d时,其出现明显增加,甚至高于标养试样.静停时间为4～6 h时,水泥石氯离子固化性能最优.蒸养水泥石中Friedel盐早期(28 d)形成数量较少,但随着后续养护时间的增加,其数量会持续增加.

Influence of Delay Period of Steam Curing on Chloride Ions Binding Capacity of Harden Cement Paste with Subsequent Standard Curing

The influence of delay period on chloride ions binding capacity of harden cement paste(HCP),based on adsorption equilibrium test,was researched.The change character of chloride ions binding capacity of HCP with subsequent standard curing time after steam curing was also discussed.XRD and DTA were used to analyze the relationship between chloride ions binding capacity of HCP and phases change of hydrated products in HCP.The results show that there are remarkable influences of steam curing on chloride ions binding capacity of HCP.The amount of bounded chloride ions in HCP increase and then decrease over delay period.When subsequent standard curing time reaches to 28 d,the amounts of bounded chloride ions in HCPs with steam curing are obviously lower than that with standard curing;when subsequent standard curing time reaches to 90 d,there are increases in the amounts of bounded chloride ions of steam curing samples,which are even higher than that of standard curing samples.The samples with 4-6 h delay periods show the best chloride ions binding capacity.The amounts of Friedel's salt in HCPs with steam curing are low at early curing period(28 d),however,they continually increase over subsequent standard curing time.