摘要
热养护能够提高超高性能混凝土(UHPC)的早期力学性能和促使UHPC的水化,但也带来了UHPC后期水稳定性问题。本文通过力学性能、SEM、XRD和孔结构分析研究了20℃标养、90℃蒸汽养护和250℃干热养护三种养护制度下试件接触水和隔绝水时对UHPC长期力学性能和微观结构的影响,结果表明:20℃标养和90℃蒸养下接触水分和隔绝水分对于试件的强度和微观结构影响较小,接触水分能够更好地提高试件的后期强度;250℃干热养护下,接触水分则会显著增加试件的微观孔隙,导致试件在后期出现明显的强度倒缩,引起严重的水稳定性问题。
Thermal curing can improve the early mechanical properties of UHPC and promote hydration of UHPC,but it also brings about the water stability in the long-term of UHPC.The mechanical properties,SEM,XRD and pore structure analysis were used to study the long-term mechanical properties and microstructure of UHPC under three curing systems:20℃standard curing,90℃steam curing and 250℃dry and hot curing which contact moisture and isolate moisture.The test results indicated that the contact and isolation water had little influence on the strength and microstructure of the specimen under 20℃standard curing and 90℃steam curing.The contact water could better improve the strength of the specimen in the later stage.The contact water would significantly increase the microscopic pores of the specimen,leading to obvious strength shrinkage in the later period and causing serious water stability problems under 250℃dry curing.
作者
罗遥凌
高育欣
闫欣宜
谢昱昊
毕耀
LUO Yaoling;GAO Yuxin;YAN Xinyi;XIE Yuhao;BI Yao(China West Construction Academy of Building Materials,Chengdu 610094,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2021年第S01期242-246,共5页
Materials Reports
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-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
水稳定性
后期水化
长期性能
UHPC
moisture susceptibility
late hydration
long-term performance
