Title: Shotcrete: Surveillance for Durable Structures--Case Histories
Author(s): Steven Gebler
Publication: Symposium Paper
Appears on pages(s): 869-900
Keywords: quality control; shotcrete; specifications; tension tests; General
Addresses shotcrete used primarily for rehabilitating concrete structures. Field experience has demonstrated that the use of detailed specifications and strict on-site surveillance can minimize workmanship problems that have been a concern with the shotcrete process. This paper discusses key points that make the specifications a useful tool. Types of shotcrete quality found in practice are illustrated. Preconstruction testing, ongoing quality control testing during construction, a core grading system, and tensile bond strength tests are discussed. Several brief case histories are presented where the use of the core grading system has proved successful. In the case histories, an independent laboratory conducted evaluations of in-place shotcrete, developed specifications for new work, and provided on-site surveillance during placement. The case histories include a drydock, cooling tower, parking garage, swimming pool, lighthouse, and two chimneys. The system adopted has resulted in structures that should provide durable, long-term service.