Destructive Testing

Overview

Destructive testing involves cutting samples from completed seams and testing them in a tensiometer for peel and shear strength. Per GRI GM14, destructive samples are typically required at a frequency of one sample per 150 lineal meters (500 feet) of seam.

GeoQC suggests a pass/fail determination based on ASTM D6392 specifications for the material type and thickness in your project, for professional review.

Recording a destructive test

1. Sample location — Select the seam and mark the cut-out location on the as-built drawing.
2. Sample number — Auto-generated or manual.
3. Associated seam — Link the sample to the specific seam from your seam log.
4. Test date — When the sample was tested (may differ from cut-out date if sent to a lab).

Entering test results

For each sample, enter the peel and shear test values:

• Peel strength — Value in lbf/in or N/mm. Enter the measured value from the tensiometer.
• Shear strength — Value in lbf/in or N/mm.
• Failure mode — Film Tearing Bond (FTB) or other failure type.

GeoQC compares these values against the ASTM D6392 specification for your material type and thickness, and suggests Pass or Fail for your review.

When a destructive test fails

If a destructive test fails, the standard response is to:

1. Take additional samples on either side of the failed location (typically at 3-meter intervals) until two consecutive passing samples are found in each direction.
2. The seam between the two closest passing samples must be re-welded or capped.
3. All additional samples and their results are documented in GeoQC with references to the original failed test.

Traceability on failure

When a test fails, GeoQC enables you to quickly identify:

• Which welder made the seam
• Which machine was used
• All other seams made by that welder/machine combination that day
• The trial weld record for that welder that day

This traceability chain is critical for regulatory compliance and is automatically maintained by GeoQC.

Sample location on drawings

Destructive test cut-out locations are marked on the as-built drawing with a distinct symbol showing the sample number. This is a required element of the final as-constructed record.