Gamma Gamma Testing

AFT has the most complete offering of integrity testing services in the industry. Our engineers and technicians have been employing these test methods since their inception. Most importantly, we go beyond testing and reporting to help our clients understand the meaning of the test results and translate our findings into real world improvements in quality and cost savings. We fully understand the strengths and weaknesses of each technology we offer and can help you solve even the most complex integrity and testing problems.


Services offered include:

    • Cross Hole Sonic Logging (CSL) – ASTM D6760

      • Single Hole Sonic Logging (SSL)

      • Cross Hole Tomography (CT)

  • Thermal Integrity Profiling (TIP) – ASTM D7949: Thermal Integrity Profiling (TIP) methods for evaluating drilled shaft concrete integrity have emerged in recent years. TIP methods use measurements of concrete temperatures along the length of the drilled shaft reinforcing cage to identify potential defect locations from zones of low temperature. TIP methods are appealing because they should be sensitive to defects outside the reinforcing cage. The detection abilities of TIP and CSL align such that virtually any significant defect should be detectible by one or both tests.


  • Gamma Gamma Testing: It is one of the most accurate non-destructive testing methods offered by AFT to analyze Cast-in-Place Foundations.

Gamma Gamma Testing

  • The process includes lowering a steel probe containing a radioactive source to the bottom of a foundation through an inspection tube and raising it out at a specified rate. As the probe is raised, Gamma photons are emitted from the radioactive source while a data acquisition system records the rate at which these particles arrive at a detector. The data are post-processed and converted to units of density. The denser the material, the more gamma particles are shielded from the detector.

    AFT’s qualified and certified engineers benefit your project by combining effective and efficient testing services with quick report turnaround.

    Have a question about the Gamma-Gamma logging method or need recommendations for testing services based on your unique project needs? Contact us and we’ll be glad to assist.

  • Low Strain Integrity Testing (SIT / PIT)- ASTM D5882: Low Strain Integrity testing is standardized in ASTM D5882. It has great advantages because of its easy execution and relatively low cost. However, it has disadvantages due to ambiguity in the interpretation of results. The test method involves coupling an accelerometer to the top of the foundation under test then generating impacts with a hand-held hammer. The reflected wave characteristics are collected on a field computer and later post-processed. In general, the integrity evaluation is based on relative increases and decreases in velocity for the effective length after the initial impact event. The reflections are then interpreted to determine the integrity of the foundation. Since a data set obtained from each pile is unique, there is not a “standard” method for interpretation. Therefore, this evaluation is largely based on experience and engineering judgment. AFT is an expert in this method, understands its limitations, and provides the most practical engineering interpretation to our clients.

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