ASTM D4452-14 PDF Download

ASTM D4452-14 is a standard practice that outlines the use of X-ray radiography to evaluate the quality of soil samples. It highlights the importance of obtaining intact and representative soil samples for geotechnical testing. However, these samples may have inherent anomalies and disturbances that are not visibly detectable. Through X-ray radiography, the standard aims to identify these anomalies and disturbances, such as natural or induced shear planes, presence of intrusions (e.g. gravels or shells), sand and silt seams, and disturbances caused by sampling.

The practice describes how X-ray radiography provides a picture of the internal structure of soil samples, irrespective of whether they are X-rayed within or outside the sampling tube. It enables the user to assess the appropriateness of sampling methods, the effects of sampling on the soil (e.g. disturbances caused by turning of thin layers, overdriving of samplers, use of bent or corroded tubes), identification of natural fissures and shear planes, presence of intrusions, and the presence of sand and silt seams, organic matter, large voids, and channels developed through leaching.

The standard emphasizes that the quality of results obtained through this practice is dependent on the competence of personnel and the suitability of equipment and facilities used. It also notes that the compliance with ASTM Practice D3740 (which evaluates the competence of testing/sampling/inspection procedures) does not guarantee reliable testing, as it is influenced by multiple factors. Lastly, the standard provides guidelines for reporting results and significant digits in accordance with ASTM Practice D6026.