Sanford Dam Auxiliary Spillway

Location: Sanford, Michigan

Award: Innovative Applications

Project Team

Owner: Four Lakes Association

Concrete and Contractor: Fisher Contracting Company

Engineer: GEI Consultants

Slag Cement: St Marys Cement

Located in Sanford, Michigan, the Sanford Dam Auxiliary Spillway is a massive renovation project that utilized Roller Compacted Concrete to meet a demanding construction schedule. The 1,200-foot-long structure was built with a series of steps reaching 24 feet high, requiring the placement of approximately 18,000 cubic yards of concrete in a remarkably short six-week window.

To manage the logistics of such a rapid, large-scale placement, the engineering team turned to a high-performance slag cement mix. With a total cementitious content of 350 pounds per cubic yard, the design utilized a 60 percent slag replacement. This high slag ratio was a mechanical necessity for this mass concrete application, as it effectively lowered the heat of hydration to keep core and surface temperature differentials well within the project's strict specifications.

The inclusion of slag cement also ensured the mix met the required 24-hour initial set time, allowing for the unique speed and layering process inherent to roller compacted concrete. Even with a low total cementitious content, the slag-integrated system provided sufficient strength development to ensure a durable and resilient spillway.

By combining the efficiency of roller compacted concrete with the thermal control of slag cement, the Sanford Dam project was completed on time and to the highest engineering standards, proving that sustainability and high-speed construction can go hand in hand.

Application Type

Application Type
% Slag Cement Replacement	60%
% Portland Cement
% Portland Limestone Cement	40%
% Other SCM (if applicable)
Aggregate	100% crushed limestone
Water/cement ratio	0.52
7-day strengths	3200 PSI
28-day strengths	4500 PSI (3500 PSI F’c)