This standard is issued under the fixed designation C ; the number 1 This test method is under the jurisdiction of ASTM Committee C-9 on Concrete. Purchase your copy of ASTM C – 15 as a PDF download or hard copy directly from the official BSI Shop. All BSI British Standards available. mm. Thickness Measurement by ASTM C Accurate measurement of thickness requires knowledge of the in-place P- wave speed. ASTM C, “Test .
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The figure is an example of aatm measurement of P-wave speed by using two transducers a known distance apart. Thus the P-wave undergoes multiple reflections between the two surfaces. Lastly, the IE method will provide information on the depth of a flaw or defect, in addition to mapping its lateral location and extent.
The absolute systematic error depends on ast, plate thickness, the sampling interval, and the sampling period. A sensitive displacement transducer next to the impact point picks up the disturbance due to the arrival of the P-wave. Training may be available at your location by one of our agents upon special arrangement.
The explanation for this 0. A short-duration stress pulse is introduced into the member by mechanical impact. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
The Spider is placed adjacent to the Mark IV transducer as shown in the photo. No other units of measurement are included in this standard. If the document is revised or amended, you will be notified by email.
Docter | GERMANN
If test equipment is assembled by the user, thickness limitations shall be established and documented. Please first verify your email before subscribing to alerts. Measure the thickness of qstm, asphalt overlays, slabs-on-ground and walls 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 Integrity of a membrane below an asphalt overlay protecting structural concrete Delamination surveys of bridge decks, piers, cooling towers and chimneystacks 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 Principle A short-duration stress pulse is introduced into the member by mechanical impact.
The LONGSHIP transducers are placed on opposite sides of the crack as shown in the sketch to the right and impact is generated on the line passing through the transducers.
Add to Alert PDF. CTG-2 requires Windows Device. The system includes a laptop computer, a data acquisition module, one Mark IV transducer with impactors, and software. The same asfm applies to reflection from an internal defect delamination or void. You can download and open this file to your own computer but DRM prevents opening this file on another computer, including a networked server.
Work Item s – proposed revisions of this standard. The frequency shift is a good indicator of the presence of a flaw if it is known that the plate thickness is constant. Please first log in with a verified email before subscribing to alerts. The Spider multiple impactor unit can be purchased as an option to increase the operating range of the systems.
The equation on page 50 is used to solve for Cpi. Work Item s – proposed revisions of this standard. Impact Echo IE investigations are performed to assess the condition or thickness of slabs, beams, columns, walls, pavements, runways, tunnels, and dams. Accurate measurement of thickness requires knowledge of the in-place P-wave speed. If the defect is just large enough to be detectable, the amplitude spectrum will show two peaks: As the voice of the U.
By positioning the cursor at the frequency associated with the flaw, the flaw depth is shown by the Viking software. Depth of Surface-Opening Cracks The DOCter can also be used to measure the depth of surface-opening cracks, using a time domain analysis. The method is based on the assumption that the concrete plate has the same P-wave speed throughout its depth.
IE investigations can also be performed to predict the strength of early age concrete if the member thickness is known. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
Already Subscribed to this document. If these conditions are not satisfied, the waveform will be of low amplitude and the amplitude spectrum will not include a dominant peak at the frequency corresponding to the thickness Eq 2. If the interface between the concrete and subgrade is rough, the amplitude spectrum will have a rounded peak instead of a sharp peak associated with a flat surface.
NDT System Add-On — Impact Echo
Powered by WordPress Theme Designed by: Measurement of D1383 Speed The figure is an example of the measurement of P-wave speed by using two transducers a known distance apart. Thus, the impact-echo method is able to determine the location of internal defects as well as measure the thickness of a solid member.
Detection of Internal Defects The P-wave generated by impact will reflect at interfaces within the concrete where there is a change in acoustic impedancewhich is defined as the product of the density and wave speed of a material. P-Wave Speed Measurement— This procedure measures the time it takes for the P-wave generated by a short-duration, point impact to travel between two transducers positioned a known distance apart along the surface of a structure.
These minimum lateral dimensions are necessary to prevent other modes 3 of vibration from interfering with the identification of the thickness mode frequency in the amplitude spectrum. A negative reflection coefficient means that the stress changes sign when the stress wave is reflected; for example, a compressive stress would be reflected as a tensile stress.
The DOCter can also be used to measure the depth of surface-opening cracks, using a time domain analysis. This assumes that the same P-wave speed is applicable at all test points.
In impact-echo testing, the P-wave is used to obtain information about the member. Alternatively, Cp may be determined by measuring the time for the P-wave to travel between two transducers with a asgm separation.