表1水泥的基本性能Table1Basicpropertiesofcement不同缓凝剂缓凝效果研究及机理分析吴昊袁查炎鹏袁王靖袁王二帅袁李永亮袁王霞渊北京市建筑工程研究院有限责任公司袁北京100039冤摘要院研究了不同缓凝剂渊传统缓凝剂尧膦酸盐缓凝剂冤复配聚羧酸减水剂后对水泥凝结时间和水化特性的影响遥结果表明院葡萄糖酸钠和蔗糖缓凝效果较好袁焦磷酸钠与柠檬酸钠对水泥凝结时间的影响程度基本接近袁膦酸盐缓凝剂对抑制水泥水化的作用效果更为平稳尧持续袁相同掺量时渊0.1%冤袁其可以推迟峰值温度出现时间2耀52h不等袁降低同龄期总水化热达250%耀1100%曰各类缓凝剂的缓凝作用多体现在对于水泥初凝时间的推迟袁膦酸盐缓凝剂相较于传统缓凝剂具备更好的缓凝效果遥关键词院缓凝剂曰凝结时间曰水化热曰水泥曰膦酸盐曰聚羧酸减水剂中图分类号院TU528.53文献标识码院Adoi:10.19761/j.1000-4637.2023.09.023.04StudyontheretardingeffectandmechanismanalysisofdifferentretardersWUHao,ZHAYanpeng,WANGJing,WANGErshuai,LIYongliang,WANGXia(BeijingBuildingConstructionResearchInstituteCo.,Ltd.,Beijing100039,China)Abstract:Theinfluenceofpolycarboxylicacidwaterreducermixedwithdifferentretarders(traditionalretarder,phosphateretarder)onthesettingtimeandhydrationcharacteristicsofcementwasstudied.Theresultsshowthatsodiumgluconateandsucrosehavegoodretardingeffect,andtheinfluenceofsodiumpyrophosphateandsodiumcitrateonthesettingtimeofcementisbasicallyclose.Theeffectofphosphateretarderoninhibitingthehydrationofcementismorestableandcontinuous,anditcandelaythepeaktemperaturefor2~52h,andreducethetotalhydrationheatofthesameageby250%~1100%whenthedosageis0.1%.Theretardingeffectofvariousretardersismainlyreflectedinthedelayoftheinitialsettingtimeofcement.Comparedwithtraditionalretarders,phosphateretardershavebetterretardingeffect.Keywords:Retarder;Settingtime;Hydrationheat;Cement;Phosphate;Polycarboxylicacidwaterreducer0引言夏季炎热天气下施工对混凝土的工作性袁尤其是对坍落度及凝结时间提出了较高要求遥合理使用聚羧酸高保坍减水剂可以在一定程度上减少新拌混凝土的坍落度损失袁保坍时长一般为2耀4h遥但在地铁工程中广泛使用的盖挖逆作法桩基尧基坑支护工程转孔咬合桩等部位施工中袁一般要求新拌混凝...
