3D打印混凝土界面性能的超声波表征与分析

Ultrasonic Characterization and Analysis of Interface Properties in 3D Printed Concrete

摘要:

为研究3D打印混凝土（3D printed concrete，3DPC）界面黏结性能对超声无损检测的影响，打印具有不同层数和时间间隔的混凝土试件，并采用超声设备对试件进行无损检测，同时利用劈裂试验得到3DPC界面黏结强度。结果表明，3DPC表现出比浇筑混凝土更慢的波传播速度和更小的波幅，且随着打印层数和间隔的增加，振幅衰减也随之增加。振幅衰减可归因于3个部分，即超声波在换能器与试件之间传输造成的损失、混凝土高度的沿程损失以及打印界面层造成的损失。与浇筑混凝土相比，3DPC的超声波幅明显偏低，随着打印层数的增加，3DPC界面黏结强度呈现先增加后下降的趋势，且与波幅损失之间存在线性关系。

Abstract:

In order to investigate the impact of interface bonding performance on the non-destructive testing of 3D printed concrete （3DPC）， concrete specimens with different layer counts and time intervals were printed and subjected to non-destructive testing using ultrasonic equipment. Additionally， splitting tests were conducted to determine the interfacial bond strength of 3DPC. It is shown that 3DPC exhibits slower wave propagation speeds and smaller amplitudes compared to cast concrete. Moreover， with the increase in the number of printed layers and time intervals， the amplitude attenuation also increases. Amplitude attenuation can be attributed to three parts： the loss caused by ultrasonic wave transmission between the transducer and the specimen， the along-path loss of concrete height， and the loss caused by the printed interface layer. The ultrasonic wave amplitude of 3DPC is significantly lower compared to cast concrete， as the number of printed layers increases， the interface bond strength of 3DPC initially increases and then decreases， showing a linear relationship with the amplitude loss.