内养护机制对再生混凝土材料宏、细观力学性能的影响研究
Study on the influence of internal curing mechanism on the macro and mesoscopic mechanical properties of recycled concrete materials
覃源 1闫鹏飞 1魏毅萌 2段明翰 1方建银3
作者信息
- 1. 西安理工大学省部共建西北旱区生态水利国家重点实验室,西安 710048
- 2. 西安科技大学建筑与土木工程学院,西安 710600
- 3. 西安理工大学土木建筑工程学院,西安 710048
- 折叠
摘要
再生混凝土作为绿色生态混凝土,其在生态水利工程中的应用较为广泛.为提高其力学性能和耐久性,采用内养护方式将再生骨料预处理至干燥、半饱和、饱和状态,分别以50％、100％的取代率取代普通混凝土,并设置干燥状态的普通混凝土作为对照组,分析了不同取代率下含水量对再生混凝土宏细观性能的影响并对各参数进行相关性分析,通过建立再生骨料吸水、解吸模型从细观尺度诠释内养护作用机理.研究结果表明,同等取代率下,养护90 d时抗压强度较优异的是含水率50％的再生混凝土组.取代率增大,孔隙增多,养护90 d时,R50P、R100P的孔隙率比7 d时分别降低14.2％、10.3％,说明含水率50％的再生骨料能一定程度上改善孔隙和界面过渡区结构;骨料吸水、解吸过程中发挥的内养护作用机制是再生混凝土后期强度持续增长的主要原因.
Abstract
As a green ecological concrete,recycled concrete is widely used in ecological water conservancy pro-jects.In order to improve its mechanical properties and durability,this paper pretreated the recycled aggregate to dry,semi-saturated and saturated states by internal curing method,replaced ordinary concrete with 50％and 100％substitution rates,respectively,and set up ordinary concrete in dry state as a control group,analyzed the influence of water content on the macro and mesoscopic properties of recycled concrete under different substitu-tion rates,and analyzed the correlation of various parameters,and interpreted the mechanism of internal curing from the mesoscale by establishing a water absorption and desorption model of recycled aggregate.The results show that under the same substitution rate,the recycled concrete group with 50％moisture content has the bet-ter compressive strength after curing for 90 days.The porosity of R50P and R100P decreased by 14.2％and 10.3％respectively after 90 days of curing compared with that at 7 days,indicating that the recycled aggregate with 50％moisture content could improve the porosity and interface transition zone structure to a certain extent.The internal curing mechanism of aggregate water absorption and desorption is the main reason for the continu-ous growth of the strength of recycled concrete in the later stage.
关键词
再生混凝土/内养护/孔隙结构/界面过渡区/吸水、解吸模型Key words
recycled concrete/internal maintenance/pore structure/interface transition area/water absorption,desorption model引用本文复制引用
基金项目
国家自然科学基金项目(52079109)
国家自然科学基金项目(52279139)
陕西省自然科学基础研究计划面上项目(2022JM-303)
出版年
2024
NETL
NSTL
万方数据