养护制度对超高性能混凝土强度的影响机理  

Affecting Mechanism of Curing Regimes on the Strength of Ultra-high Performance Concrete

作　　者：孙嘉伦 张春晓 毛继泽[3] 李明哲 高小建[1] SUN Jialun;ZHANG Chunxiao;MAO Jize;LI Mingzhe;GAO Xiaojian(School of Civil Engineering,Harbin Institute of Technology,Harbin 150001,China;Research Institute for National Defense Engineering of Academy of Military Science PLA China,Luoyang 471023,Henan,China;College of Aerospace and Civil Engineering,Harbin Engineering University,Harbin 150001,China)

机构地区：[1]哈尔滨工业大学土木工程学院,哈尔滨150001 [2]中国人民解放军军事科学院国防工程研究院工程防护研究所,河南洛阳471023 [3]哈尔滨工程大学航天与建筑工程学院,哈尔滨150001

出　　处：《材料导报》2024年第18期62-66,共5页Materials Reports

基　　金：国家自然科学基金联合重点项目(U2106220);黑龙江省自然科学基金重点项目(ZD2021E007)。

摘　　要：超高性能混凝土(UHPC)具有优异的力学性能和耐久性,被广泛应用于各种工程,其中养护是保证其高性能的重要条件。本工作从养护制度角度出发,通过微观表征的方法,研究了不同养护制度(标准养护、蒸汽养护、干热养护和组合养护)对UHPC微观结构的影响规律,进而说明养护对UHPC强度的提升机理。结果表明:与标准养护相比,三种热养护均显著改善了C-S-H凝胶的形貌特征和空间分布规律,其中组合养护的改善效果最佳。此外,养护条件的改变也显著影响了内部纤维与基体粘结性能以及界面过渡区稳定性,这是由于高温高湿环境促进了水泥的二次水化,生成大量C-S-H凝胶,并消耗了氢氧化钙(CH)等弱胶凝性物质,进一步优化了混凝土内部孔隙,使其微观结构更为致密。这说明,必要的温湿度环境可有效改善UHPC的微观结构,这也是UHPC强度提升的重要原因。Ultra-high performance concrete(UHPC)has excellent mechanical properties and durability,and is widely used in various engineering,among which curing is an important condition to ensure its high performance.From the perspective of curing regime,through the method of microstructure characterization,the effects of different curing regimes(standard curing,steam curing,dry heat curing and combined curing)on the microstructure of UHPC were studied,and then the mechanism of improving the strength of UHPC was explained.The research shows that different curing regimes have a great influence on the microstructure of ultra-high performance concrete;compared with standard curing,the three thermal curing significantly improved the morphological characteristics and spatial distribution of C-S-H gel,among which the improvement effect of combined curing.In addition,the change of curing conditions also significantly affects the bonding properties of internal fibers and the matrix stability of the interfacial transition zone.This is because the high temperature and high humidity environment promote the secondary hydration of cement,generate a large amount of C-S-H gel,and consumes calcium hydroxide(CH),making its microstructure more dense.This indicates that necessary temperature and humidity environment can effectively improve the microstructure of UHPC,which is also an important reason for the strength improvement of UHPC.

关 键 词：超高性能混凝土 养护制度 力学性能 微观结构 

分 类 号：TU528.31[建筑科学—建筑技术科学]