Study on the influence of MWCNTs on UHPC mechanical properties under different mixing methods
The study investigates the effects of two mixing methods,dual-shaft mixing and vibration mixing,on the performance and mechanical properties of ultra-high-performance concrete(UHPC)incorporating multi-walled carbon nanotubes(MWCNTs).The results indicate that the workability of UHPC significantly decreases when mixed with dual-shaft mixers after the addition of MWCNTs,while it remains relatively unchanged with vibration mixing.Both dual-shaft and vibration mixing methods can improve the compressive strength,tensile strength,and flexural performance of UHPC to some extent when MWCNTs are incorporated,with vibration mixing showing superior results.When using vibration mixing and incorporating 0.05%MWCNTs,the compressive strength,tensile strength,and flexural strength of UHPC increased by 3.0%,30.0%,38.0%respectively compared to the control group.The flexural toughness indices I5,I10,I20 increased by 50.8%,71.6%,85.6%respectively,and the flexural toughness ratio improved by 63.7%.MWCNTs have shown excellent reinforcing and toughening effects.