粉煤灰和钢纤维对超高性能混凝土抗冲磨性能的影响
Effects of Fly Ash and Steel Fiber on Abrasion Resistance of Ultra-High Performance Concrete
丁大伟 1郭子涵 1张伟 1张秀新 1马怡彤 1王鑫鹏 1侯东帅1
作者信息
- 1. 青岛理工大学土木工程学院,青岛 266520
- 折叠
摘要
为探明粉煤灰和钢纤维对超高性能混凝土(UHPC)抗冲磨性能的影响机理,本文采用宏观力学试验、水下抗冲磨试验等测试方法,结合SEM、MIP等微观表征技术,研究了粉煤灰和钢纤维对UHPC工作性能、力学性能、微观结构和抗冲磨性能的影响.结果表明,粉煤灰取代部分水泥使UHPC水化放热峰的出现延缓了约3 h,3 d累计放热量减少了 18％,同时显著提高了 UHPC的工作性能.粉煤灰的掺入降低了 UHPC的早期力学性能,钢纤维的掺入提高了 UHPC的抗折强度和抗压强度;蒸汽养护条件下,钢纤维与粉煤灰复掺使UHPC抗折强度和抗压强度分别提高了 82％和47％.此外,粉煤灰对UHPC的抗冲磨性能影响很小,而钢纤维提升了 UHPC的抗冲磨性能,钢纤维与粉煤灰复掺使UHPC的抗冲磨强度提升了 58％.UHPC的抗压强度与抗冲磨强度呈现明显的正相关性.粉煤灰的掺入降低了最可几孔径、孔隙率和毛细孔含量,使基体内部结构更加均匀、密实.
Abstract
In order to investigate the effects of fly ash and steel fiber on the abrasion resistance of ultra-high performance concrete(UHPC),this paper performed macroscopic mechanical test,underwater abrasion resistance test and microscopic characterization such as SEM and MIP to investigate the effects of fly ash and steel fiber on the workability,mechanical properties,microstructure,and abrasion resistance of UHPC.The results show that the replacement of cement by fly ash delays the emergence of hydration peak by about 3 h,and the cumulative heat flow at 3 d is reduced by 18％,significantly improving the workability of UHPC.The incorporation of fly ash reduces the mechanical properties of UHPC in the early stage and has no effect on the mechanical properties in the later stage.The incorporation of steel fiber improves the flexural strength and compressive strength of UHPC.The flexural strength and compressive strength are increased by 82％and 47％respectively due to the composite mixing of steel fiber and fly ash under steam curing.The addition of fly ash has little effect on the abrasion resistance of UHPC,while the addition of steel fiber improves the abrasion resistance of UHPC,and the composite mixing of steel fiber and fly ash increases the abrasion resistance of UHPC by 58％.The compressive strength and abrasion resistance strength of UHPC show a significant positive correlation.The incorporation of fly ash reduces the most available pore size,porosity and capillary pore content,making the internal structure of matrix more uniform and denser.
关键词
粉煤灰/钢纤维/超高性能混凝土/抗冲磨性能/微观结构/力学性能Key words
fly ash/steel fiber/ultra-high performance concrete/abrasion resistance/microstructure/mechanical property引用本文复制引用
基金项目
国家重点研发计划重点专项(2022YFE0133800)
出版年
2024
国家科技期刊平台
NSTL
万方数据