Reliability of Crack Detection Methods for Baseline Condition Assessments

This is the authors' abstract. We don't add key points for this paper.

Despite billions of dollars of annual exposure from claims and litigation related to construction-induced damage, there are no quantitatively based, agreed upon standards or procedures as to what constitutes due diligence with respect to a preconstruction, condition assessment. Similarly, the relative accuracy, reliability, and costs for various inspection approaches are not well established. This paper compares the relative performance capabilities of crack detection by sidewalk-based manual inspection with digital photography, terrestrial Light Detection and Ranging (LiDAR), and elevated manual inspections based on two brick and two concrete buildings (8.2–14.3 m high) in Dublin, Ireland. Results showed that nonmanual methods tended to overpredict crack widths by at least 5 mm and underestimate crack lengths by one-half. Digital photography, however, detected the shortest cracks (as short as 17 mm) and had no significant decline in accuracy beyond 12 m high, which has the added benefit of generating a permanent objective record. The terrestrial LiDAR proved neither particularly accurate nor cost-effective at the selected point density of less than 2mm×2mm. Finally, operator-based reliability problems emerged with all methods with discrepancies of at least 11%. Overall, digital photography taken and archived, but not analyzed, was the most cost-effective, accurate, and reliable approach.