摘要
针对京雄高铁雄安站房泵送大体积清水混凝土制备需求,通过室内试验和模拟实体施工监测开展研究,考察了单掺粉煤灰(掺量25%、35%、45%)对混凝土工作性能、力学性能、外观质量和水化温升的影响。结果表明:粉煤灰可以改善混凝土和易性和振动黏度系数,有利于减少外加剂用量和提高气泡排出能力,但过量掺入粉煤灰将加剧坍落度经时损失、影响混凝土早期抗压强度提升以及导致混凝土外观水纹现象等。实践表明,在既有混凝土配合比中控制粉煤灰掺量35%既可以同时兼顾混凝土的工作性能、力学性能和外观质量,满足泵送大体积清水混凝土的制备需求。
Laboratory experiments and temperature monitor on-site were conducted to meet the need of preparing pump,mass and fair-faced concrete used in the construction of Xiong′an railway station.Influence of fly ash content on fresh,mechanical performance and appearance quality was studied,the results showed that fly ash could improve workability and viscosity under vibration of fresh concrete,which helped to reduce chemical admixture dosage and accelerate air bubble escaping from concrete.But excess amount of fly ash in concrete would aggravate slump loss,delay early-age compressive strength development and produce watermark on surface of concrete.Practice proved finely fresh,mechanical performance and appearance quality could be obtained simultaneously by using 35%content of fly ash to meet the need of preparing pump,mass and fair-faced concrete.
作者
张昆
曹太然
张建康
黄直久
王益民
田福太
姜骞
ZHANG Kun;CAO Tairan;ZHANG Jiankang;HUANG Zhijiu;WANG Yimin;TIAN Futai;JIANG Qian(China Railway 12th Bureau Group Co.,Ltd.,Taiyuan 030024,China;State Key Laboratory of High Performance Civil Engineering Materials,Nanjing 210000,China)
出处
《混凝土》
CAS
北大核心
2021年第9期102-105,共4页
Concrete
基金
“十三五”国家重点研发计划战略性国际科技创新合作重点专项(2016YFE0206100)
江苏省自然科学基金项目(BK20181127)。
