摘要
热养护能够提高超高性能混凝土(UHPC)的早期力学性能,促使UHPC水化,但对UHPC长期性能的发展尚未有系统深入的研究。通过力学性能测试、SEM和XRD研究了五种养护温度(20℃标养、90℃蒸汽养护、120℃干热养护、200℃干热养护和250℃干热养护)对UHPC长期力学性能发展以及水化的影响。结果表明,热养护能够促进UHPC早期水化,显著提升UHPC的早期抗压强度,特别是养护温度超过200℃时,能够生成明显的硬硅钙石提高UHPC的早期抗压强度。不同养护温度对于UHPC后期抗压强度的影响则不尽相同,90℃蒸养和120℃干热养护后UHPC试件的后期抗压强度仍然能持续增长,而200℃和250℃干热养护后试件的后期抗压强度则出现显著降低的趋势,后期抗压强度的变化主要取决于UHPC早期水化后内部剩余的未水化颗粒的含量。
The mechanical property and hydration of ultra-high performance concrete(UHPC)are enhanced by heat curing.However,the long-term performance of UHPC has not been studied systematically.The mechanical performance testing,scanning electron microscope(SEM),and X-ray diffraction(XRD)were used to research the long-term mechanical performance and hydration of UHPC after 5 different curing temperatures(20℃standard curing,90℃steam curing,120℃dry heat curing,200℃dry heat curing and 250℃dry heat curing).The test results indicate that the early compressive strength of UHPC is significantly improved by accelerating the hydration,especially the curing temperature exceeding 200℃due to the generation of xonotlite.The influences of different curing temperatures on the long-term strength of UHPC are different.The long-term compressive strength of UHPC still continues to grow after 90℃steam curing and 120℃dry heat curing,while the long-term compressive strength of UHPC has a significant decrease after 200℃dry heat curing and 250℃dry heat curing.The change of long-term compressive strength mainly depends on the content of remaining unhydrated particles in UHPC after early hydration.
作者
罗遥凌
杨文
谢昱昊
闫欣宜
毕耀
LUO Yaoling;YANG Wen;XIE Yuhao;YAN Xinyi;BI Yao(China West Construction Academy of Building Materials Co.,Ltd.,Chengdu 610015,China)
出处
《硅酸盐通报》
CAS
北大核心
2021年第2期431-438,共8页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金青年项目(52002041)
中国住房和城乡建设部研究开发项目(K2019248)
中建股份课题(CSCEC-2019-Z-24,CSCEC-2019-Z-17-6)
中建西部建设股份有限公司科技研发计划(ZJXJ-2019-13)。
关键词
UHPC
水化
抗压强度
抗折强度
热养护
养护温度
UHPC
hydration
compressive strength
flexural strength
heat curing
curing temperature
