Integrating Advance Evaluation Techniques with Terra Cotta Examinations

摘要

Fundamental evaluation techniques for terra cotta facades, which include at-arms-length visual review and mechanical sounding, are unsurpassed in determining the existing condition of individual terra cotta units. However, extrapolating the information gained from these techniques to determine the overall condition of assemblies and potential problems is problematic at best and often speculative in nature. Advance evaluation techniques, including impulse response and fiberscope optical survey, can readily identify conditions that do not present themselves to fundamental techniques. These conditions include; excessive stress due to stacking effect at shelf angles, improperly supported corner units, and corrosion of J-hooks, rods, anchors and ties. When this type of additional information is integrated with the information from fundamental techniques the evaluation evolves from being an inventory of existing conditions to a comprehensive understanding of facade performance. This paper will address some of the special techniques that are available for evaluating the nature and extent of distress in terra cotta cladding systems during the performance of a field investigation. Techniques discussed include the use of optical borescopes, in-situ measurement of stresses and impulse response testing.