Title:
Construction of the Hoover Dam Bypass
Author(s):
Jeff St. John
Publication:
Concrete International
Volume:
33
Issue:
2
Appears on pages(s):
30-35
Keywords:
high-performance concrete, mass concrete, cooling, pumping
DOI:
Date:
2/1/2011
Abstract:
Development of the mixture proportions for the concrete arches of the Hoover Dam Bypass Bridge began two years before the first arch segment was cast. Requirements for the high-performance concrete had been established by the design and ownership team. They included strength, aggregate selection, and thermal control requirements. The construction team added requirements for pumpability, flowability, and long set time to overcome delivery and placement challenges, and they added the requirement for rapid strength gain to minimize form traveler cycle time. Project specifications included detailed thermal control requirements for mass concrete and for the concrete in the arches. Although the scale of the arch and the high ambient temperatures created difficult conditions, the construction team developed successful procedures for placing the concrete and controlling the temperature during curing.