摘要
通过测试再生混凝土坍落度、立方体抗压强度及劈裂抗拉强度,并对再生混凝土微观形貌、矿物组成进行分析,探究矿物掺合料种类及掺量对再生混凝土力学性能的影响。研究结果表明:将粉煤灰分别与矿渣、硅灰、偏高岭土组合使用能够明显改善再生混凝土和易性;单掺矿物掺合料中,偏高岭土能显著提升再生混凝土力学性能,相较于基准组,养护龄期90 d时,抗压强度和劈拉强度分别提升24.0%和11.0%;复掺矿物掺合料中,粉煤灰-偏高岭土对混凝土的劈拉强度提升效果突出,劈拉强度提升14.0%,抗压强度提升6.5%;三掺矿物掺合料中,粉煤灰-硅灰-偏高岭土对再生混凝土的劈拉强度提升较好,劈拉强度提升9.8%,抗压强度提升4.6%;粉煤灰-矿渣-硅灰-偏高岭土四掺再生混凝土力学性能表现良好,抗压强度最高提升18.4%,劈拉强度最高提升15.5%。
By testing the slump,cubic compressive strength and splitting tensile strength of recycled concrete,and analyzing the micro-morphology and mineral composition of recycled concrete,the influence of mineral admixture types and content on the mechanical properties of recycled concrete is explored.The research results show that the use of fly ash in combination with slag,silica fume,and metakaolin can significantly improve the workability of recycled concrete.Among the single mineral admixtures,metakaolin can significantly improve the mechanical properties of recycled concrete.Compared to the benchmark group,when the curing age is 90 days,the compressive strength and the split tensile strength are increased by 24.0% and 11.0% respectively.Among the mixed mineral admixtures,the fly ash-metakaolin composite admixture has a prominent effect on the split tensile strength of the concrete.The tensile strength is increased by 14.0%,and the compressive strength is increased by 6.5%.Among the three-mixed mineral admixture,the split tensile strength of fly ash-silica fume-metakaolin recycled concrete is improved better,the split tensile strength is increased by 9.8%,and the compressive strength is increased by 4.6%.Four-mixed of fly ash-slag-silica fume-metakaolin recycled concrete performs well,with a maximum increase of 18.4% in compressive strength and a maximum increase of 15.5% in split tensile strength.
作者
侯泽宇
李子昂
王家滨
李恒
HOU Zeyu;LI Ziang;WANG Jiabin;LI Heng(School of Civil&Architectural Engineering,Xi′an Technological University,Xi′an 710021,China;Xi′an Key Laboratory of Civil Engineering Testing and Destruction Analysis onMilitary-Civil Dual Use Technology(XATU),Xi′an 710021,China)
出处
《混凝土》
CAS
北大核心
2023年第1期58-63,共6页
Concrete
基金
国家自然科学基金(51908440)
大学生创新创业训练计划项目(S202010702085)。
关键词
再生混凝土
矿物掺合料
力学性能
界面过渡区
recycled aggregate concrete
mineral admixtures
mechanical property
interface transition zone
