纤维对含粗骨料超高性能混凝土高温性能的影响

Influence of Fiber on High Temperature Performance of Ultra-high Performance Concrete With Coarse Aggregate

为了探究改善超高性能混凝土(UHPC)高温性能的措施,从力学性能、质量损失、超声检测等方面研究了纤维(不掺纤维、单掺钢纤维、混掺钢纤维与合成纤维)对UHPC高温性能的影响。结果表明:当纤维掺量增加时,UHPC的工作性与抗压强度均随之下降,抗折强度则先升后降;随着目标温度的升高,UHPC的残余抗压强度先升后降,损伤逐步加重;纤维的加入可以延缓裂缝的发展,混掺钢纤维与合成纤维可以有效改善UHPC高温爆裂行为。

In order to explore the measures to improve the high temperature performance of ultra-high performance concrete(UHPC),the influence of fiber(non-fiber,single steel fiber,mixed steel fiber and synthetic fiber)on the high temperature performance of UHPC was studied from the aspects of mechanical properties,mass loss and ultrasonic testing.The results show that when the fiber content increases,the workability and compressive strength of UHPC decrease,while the flexural strength increases first and then decreases.With the increase of the target temperature,the residual compressive strength increases first and then decreases.The addition of fiber can delay the development of cracks,and the mixing of steel fiber and synthetic fiber can effectively improve the high temperature burst behavior of UHPC.