Title: Evaluation of the Integrity of Some Large Concrete Structures Using NDT
Author(s): Allen G. Davis and Bernard H. Hertlein
Publication: Symposium Paper
Appears on pages(s): 333-356
Keywords: field tests; mass concrete; nondestructive tests
Large concrete structures such as dams and bridge abutments and piers built over 50 years ago were usually constructed of mass concrete with no or little reinforcing steel. Most of these structures are in service today, and make up a considerable part of the infrastructure. Concern about their reliability and residual life now prompts owners to initiate structural inspections. The traditional approach of coring and visual inspection alone does not necessarily provide a full over for this evaluation. The more familiar nondestructive tests (NDT) such as rebound hammer, ultrasonic pulse velocity and similar surface tests are usually unsuccessfbl in providing information about bulk concrete quality at depth. This paper reviews two novel NDT methods that can address this problem: sonic ogging and parallel seismic, and presents three case histories that illustrate their application.