摘要
为研究-20℃条件下早强掺和料对砂浆性能的影响,测试了不同早强掺和料掺量下砂浆的工作性能、力学性能、体积稳定性以及耐久性。结果表明:-20℃条件下,早强掺和料在10.0%~22.5%掺量下能保证15 min的可工作时间,掺量越高砂浆初凝时间越短。早强掺和料可显著提高-20℃条件下砂浆的抗压和抗折强度,且砂浆经-20℃养护7 d后转入标准条件继续养护28 d的强度,接近全程标准养护28 d的强度。此外,早强掺和料对砂浆28 d内的收缩有降低作用,且在15.0%及以下掺量时不会引起砂浆二次钙矾石开裂风险。早强掺和料掺量大于10.0%的砂浆试件均可满足300次抗冻的要求。
To explore the impact of early strength admixtures on mortar performance at-20℃,the workability,mechanical properties,volume stability,and durability of mortar were tested under different early strength admixture dosages.The results show that under the condition of-20℃,the early strength admixture can ensure a working time of 15 min at a dosage of 10.0%~22.5%.The higher the dosage,the shorter the initial setting time of the mortar.Early strength admixture can significantly improve the compressive and flexural strength of mortar under-20℃conditions,and the strength of mortar after negative temperature curing to standard curing for 28 d is close to the strength of standard curing for 28 d.In addition,early strength admixtures have a reducing effect on the shrinkage of mortar within 28 d,and at a dosage of 15.0%or less,there is no risk of secondary ettringite cracking in mortar.Mortar specimens with an early strength admixture content greater than 10.0%can meet the requirement of 300 frost resistance cycles.
作者
郁培云
刘相会
李书明
张驰
郑新国
李秋原
李钢
YU Peiyun;LIU Xianghui;LI Shuming;ZHANG Chi;ZHENG Xinguo;Li Qiuyuan;LI Gang(Railway Engineering Research Institute,CARS,Beijing 100081,China;State Key Laboratory for Track Technology of High-speed Railway,Beijing 100081,China;CARS,Beijing 100081,China;China Railway Shanghai Group Co.Ltd,Shanghai 200071)
出处
《铁道建筑》
北大核心
2025年第11期146-150,共5页
Railway Engineering
基金
国家重点研发计划(2022YFB2603300)
中国铁路上海局集团有限公司科研课题(2025148)
中国铁路北京局集团有限公司科研课题(2025BT02)。
关键词
砂浆
负温
早强掺和料
强度
抗冻性
mortar
negative temperature
early strength admixture
strength
frost resistance
