s'MASH
s'MASH
The s’MASH: Standard Practice for Evaluating the Condition of Concrete Plates Using the Impulse-Response test Method.
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.
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
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
- Equipped with 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:
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The acquisition box can also be used for DOCter impact-echo testing as a combined system.
ASTM C1740, “Standard Practice for Evaluating the Condition of Concrete Plates Using the Impulse-Response Method.”