Author: Victoria García Acero

The impact-echo method is based on monitoring the periodic arrival of reflected stress waves generated by a small mechanical impact. Unlike traditional ultrasonic pulse velocity testers that require access to both faces of a member and it is not possible to determine the depth to anomalies,   Mirador requires access to only one face and is able to obtain information on the depth of  internal flaws or the thickness of a solid member. The Echolyst software for data acquisition and 2D/3D visualization makes the impact-echo technique more friendly and easier to interpret.   

Impact-Echo test.

• Measure the thickness of pavements, asphalt overlays, plate-like concrete elements like slabs or walls, etc.
• Detect the presence and depth of voids and honeycombing
• Detect voids below slabs-on-ground
• Evaluate the quality of grout injection in post-tensioning cable ducts or joints for precast elements
• Integrity of a membrane below an asphalt overlay protecting structural concrete
• Delamination surveys of bridge decks, piers, cooling towers, chimneystacks, etc.
• Detect debonding of overlays and patches
• Detect ASR damage and freezing-and-thawing damage
• Measure the depth of surface-opening cracks
• Estimate early-age strength development (with proper correlation)

Impact-Echo test.

• Data Acquisition System: 
  • 2 channels, 4 MB/channel 
  • 8 bits resolution, 50 MHz bandwidth 
  • -5V to 5V Input Voltage Range
  • USB interface

• Dry contact, high sensitivity, piezoelectric handheld transducers 
• Equipped with Echolyst software that allows:
  • real-time waveform display while testing
  • create 2-D and 3-D visual representations 
  • look at reflecting interface on different cutting planes
  • audio assisted prompts to speed up data acquisition
  • superimpose test results on real image of test location
  • report generation

• Accuracy (assuming a constant P-wave speed):
  • Thickness measurement, direct calibration: ± 2%
  • Thickness measurement by surface P-wave speed measurement: ± 3%
  • Depth of surface-opening cracks: ± 4%

• Operating conditions: Temperature: -10 to 50 °C,  RH ≤ 95 %

Mirador -3000 Kit

Includes:

Mirador-5000 Kit

Includes:

To be ordered separately

• Technical Data Sheet

• ECH-TDS Echolyst

• Publications

• ASTM C1383, “Test Method for Measuring the P-Wave Speed and the Thickness of Concrete Plates Using the Impact-Echo Method”

MIRA is based on the ultrasonic pitch-catch method and uses an antenna composed of an array of dry point contact (DPC) transducers, which emit shear waves into the concrete. The 4 by 12 transducer array is under computer control and the recorded data are analyzed to create a 2-D image of the reflecting interfaces within the cross section below the antenna. The series of 2-D images obtained from a 2- dimensional surface scan of the test object are transferred to a computer with IntroView imaging software. The software assembles the 2-D slices into a complete 3-D image of the test object. The 3-D image can then be manipulated for interpretation of test results. 

Ultrasonic pulse-echo tomographer, flaw detector.

• Thickness measurement
• Detection of voids and honeycombing in concrete elements
• Detection of voids in grouted tendon ducts
• Detection of poor-quality bond in overlays and repairs
• Detection of delaminations
• Detection of lack of support behind tunnel linings and below slabs on grade.

• Integrated 5.7” TFT color screen. 
• Low frequency, broadband, dry point contact shear-wave transducers with wear-resistant ceramic tips 
• Spring loaded 4 x 12 transducers in the antenna array
• 10 to 100 kHz working frequency range
• Nominal frequency converter = 50 kHz
• Ultrasound speed range: 1,000 to 10,000 m/s
• Dimensions: 370 × 150 × 145 mm (without handles)
• Weight: 4.5 kg 
• Testing depth: 40 to 2,000 mm (depending on the concrete quality, member’s lateral dimensions and amount of reinforcement)
• 7 Gb flash memory
• USB 2.0 interface
• 11.2 V rechargeable battery, 5 h operating life
• Protection class IP54
• IntroView software for 3-D tomographic display
• Operating conditions: -10 °C to 50 °C, < 95% RH
• Error of the depth of a defect, mm, where H is the measured depth = ± (0.05 ∙ H + 10)

MIRA (MIR-1000) Tomographer

Ultrasonic pulse-echo tomographer.

• Technical data-sheet 
• Publications

More documentation is available upon request.

No standards available for this NDT system.

The s’MASH uses a low-strain impact, produced by an instrumented rubber tipped hammer, to send stress waves through the tested element. The impact causes the element to vibrate in a bending mode and a velocity geophone transducer, placed adjacent to the impact point, measures the amplitude of the response. The resultant velocity spectrum is divided by the impact force spectrum, to obtain the mobility as a function of frequency. The software analyses this information and derives into 4 parameters (average mobility, mobility slope, dynamic stiffness and voids ratio) that are used for integrity evaluation of the testing area by means of visual representations with contour plots.

s’MASH Impulse-Response test.

• Detecting voids beneath concrete slabs in highways, spillways, and floors 
• Detecting curling of slabs on ground
• Locating delaminations and honeycombing in bridge decks, slabs, walls and large structures such as dams, chimney stacks, and silos 
• Detecting the presence of damage due to freezing and thawing 
• Detecting the presence of alkali-silica reaction (ASR) 
• Detecting debonding of asphalt or concrete overlays and repair patches from concrete substrates 
• Evaluating the integrity of anchoring systems of wall panels 
• Evaluating the effectiveness of the load transfer system in transmitting frorces across joints in concrete structures

s’MASH Impulse-Response test.

• Data Acquisition System: 

• • 2 channels, 4 MB/channel 
  • 8 bits resolution, 50 MHz bandwidth 
  • -5V to 5V Input Voltage Range
  • USB interface

• Omni-directional (360o) dry contact geophone transducer
• Electric impact hammer with external force sensor
• Windows OS based s’MASH software for real-time waveform displaying and creation of contour plots for visual representation of average mobility, mobility slope, dynamic stiffness and voids ratio
• Operating conditions: Temperature: -10 to 50 °C,  RH ≤ 95 % 

s’MASH-4000 Kit

Includes:

The acquisition box can also be used for DOCter impact-echo testing as a combined system.

• Technical Data Sheet
• Publications

ASTM C1740, “Standard Practice for Evaluating the Condition of Concrete Plates Using the Impulse-Response Method.”