Assessment of Underwater Concrete Technologies for In-the-Wet Construction of Navigation Structures
Abstract
Major recent developments by the U.S. Army Corps of Engineers in the underwater construction of locks and dams include the in-the- wet" or "offsite prefabricated" construction method. This method uses precast concrete modules as the in situ form into which concrete is placed directly underwater without use of a cofferdam. The underwater concrete is designed to work in composite with the precast concrete. In depth studies have shown that in-the-wet construction will lead to substantial savings in cost and construction time, in addition to minimizing the effect on river traffic during construction and substantially reducing or eliminating the impact on navigation during rehabilitation. Many outstanding examples exist of high quality concrete placed underwater. However, a significant number of failures have occurred which have resulted in excessive cost overruns and delays. Due in large part to improper concrete mixtures and improper placement techniques, these failures might have been prevented if state of-the-art underwater concrete technology had been more widely disseminated among engineers and contractors. This report focuses on the basic performance requirements of underwater concrete materials, with emphasis on practical construction issues for in-the-wet construction of navigation structures. Latter portions of the report address underwater concrete construction procedures. A general checklist for underwater concrete specifications is provided.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1999
- Accession Number
- ADA369259
Entities
People
- Ben C. Gerwick
- Dale E. Berner
- Sam X. Yao