What materials can be inspected with the A1040 MIRA 3D Concrete Ultrasonic Tomograph?
The A1040 MIRA 3D Ultrasonic Low Frequency Tomograph is suitable for all inhomogeneous materials that cannot be tested with “conventional” ultrasonic flaw detectors (frequency range 1 – 10 MHz). The following materials can be considered “inspectable” materials:
Concrete, rock, marble
Refractory materials/ceramics, such as firebricks
Composites, such as fiberglass parts with thicker walls, plexiglass
Highly attenuating materials, such as coal-rock, coal-cement mixtures
Carbon electrodes
What are the typical applications for ultrasonic pulse echo tomography with the A1040 MIRA 3D fully focused ultrasonic tomograph?
Measuring the thickness of concrete structures
Location of structural metal elements (rebars, tubes, pipes)
Detection of defects in concrete (e.g. voids, delaminations, cracks, honeycombs, cold joints)
Measurement of the depth of open cracks using a single-side channel
Applications include: tunnel linings, hydraulic structures, building structures, bridge structures, and others
What is the “smallest” element or defect in concrete that can be detected using the A1040 MIRA 3D portable 3D ultrasonic tomograph?
The detection and resolution capabilities depend on several factors, such as:
Material properties (e.g. aggregate size), thus applying the appropriate detection frequency
The reflectivity of the defect/structural element, which in turn depends on its shape and orientation in the structure
Deep location of the defect/structural element
Effective aperture of the device (20 cm for the A1040 MIRA 3D)
On an “average” basis, we can say that for a slender cylindrical reflector (like a rebar) the detectable diameter might be 10 mm, while for a “round bubble” the detectable diameter might be 20 mm.
What is the achievable testing range of ultrasonic pulse-echo testing?
The attenuation of sound waves in concrete depends on material properties, such as aggregate size or density, so the testing range must always be considered as a derivative of the optimal testing frequency. When using the optimal testing frequency in combination with a sufficient effective aperture of the instrument, the achievable testing range is up to 2 – 3 meters. Advanced signal processing techniques and ultrasonic imaging techniques, such as the use of coded excitation sequences (E-Boosting), can double the instrument’s testing range to 4 – 6 meters.
Do the INTROVIEW® and MIRA NEO® software support merging multiple scans collected on a square?
Both available software for UT data visualization and analysis can perform 3D image reconstruction when scans are collected in the so-called MAP mode, when equidistant measurement points are distributed over the area of interest. The 3D representation of the UT results by overlapping multiple scans provides the most comprehensive information about the structure being tested.
Are there established standards for ultrasonic pulse-echo testing?
At present, there are technical standards for the inspection of prefabricated residential buildings in China, including various local standards:
Ministry of Housing and Urban-Rural Development: JGJT485-2019-Technical Standards for Inspection of Prefabricated Residential Buildings
Standards of China Association for Engineering Construction Standardization: T/CECS 1189-2022 Inspection Standards for Prefabricated Concrete Structures
Jiangsu Province: DB32∕T 3754-2020 Technical Specifications for Inspection of Prefabricated Monolithic Concrete Structures
Jiangsu Province: TJSJTQX 51-2024 Technical Specifications for Array Ultrasonic Detection of Internal Defects of Cement Concrete
Guangdong Province: DBJT15-199-2020 Technical Standards for Inspection of Prefabricated Concrete Structures
Zhejiang Province: DBJ33/T 1270-2022 Technical Specifications for Inspection of Prefabricated Concrete Structures
Shanghai: DB31/T 1200-2019 Technical Specifications for Detecting Concrete Defects by Phased Array Ultrasonic Imaging
Shandong Province: DB37T 5106-2018 Technical standards for on-site inspection of prefabricated concrete structures
Hebei Province: DB13 (J) -T8327-2019 Technical standards for inspection of prefabricated concrete structures
And other provinces
Currently in the European standard EN 12504-4, it is used to determine pulse velocity. It was then included in the standard EN13791 for in-situ compressive strength. However, there is currently no international standard for pulse echo imaging and defect detection. The only available guide for pulse echo defect detection is the German Association for Non-destructive Testing Guide B4. It is also covered by the German Highway Administration’s Guide to Measuring Tunnel Lining Thickness (ZTV-ING Teil 5 Tunnelbau) and ACI 228.2R.
Can water-filled voids in concrete be identified using MIRA 3D?
Any voids filled with a material of different density than the concrete can be visualized with the A1040 MIRA 3D ultrasonic concrete tomography scanner, provided that they are of sufficient spatial size to exceed ½ the ultrasonic wavelength, where wavelength = wave speed/frequency.
Can ultrasonic pulse echo detect voids beneath rebar?
Ultrasonic pulse echo tomography is the most suitable technique for detecting voids, honeycombs and delaminations, even beneath several rebar grids. Dense rebar structures prevent the GPR signal from penetrating deep into the structure, but the ultrasonic pulse echo signal can detect deeper voids, making it more suitable for structures with dense rebar.
How close to the surface can the ultrasonic pulse echo technique measure?
Locating rebar in the near field with the A1040 MIRA 3D. The following figure shows a ∅16 mm rebar at a depth of 17 mm (25 mm from the center of the rebar), which is measured to be 26.2 mm.
Ultrasonic Tomography User Guide: Answers to frequently asked questions, learn how to use it
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Related product links:
A1040 MIRA Ultrasonic Tomography
A1040 MIRA 3D Ultrasonic Tomography
A1040 MIRA 3D PRO Concrete Ultrasonic 3D Imaging Detector