In 2019, the Mississippi Department of Transportation (MDOT) approved the use of Rapid Set® Cement for the first time on a bridge deck closure pour. The concrete deck slab was installed Nov. 6 at the I-55 exit flyover in Jackson, the state’s capital city.

MDOT specified the concrete must reach 4000 psi compressive strength in six hours. Rapid Set® Cement is a fast-setting, high-performance hydraulic cement that is used to create concrete with a fast return to service, high-early strength and increased durability. It also has inherent sulfate resistance and low shrinkage, making it ideal for highway pavement and bridge decks.

Jackson, Miss.-based contractor Key Constructors performed the work, which consisted of installing a 280-foot-long concrete slab 2 feet, 5 inches wide and 14 inches deep. The deck slab connects a newly placed precast concrete slab to existing pavement, widening the bridge from one lane to two lanes.

This project also was the first time the state approved use of a volumetric mixer as the concrete material delivery system. Concrete Strategies, based in Overland, Mo., supplied the concrete mixture.

Work was completed the same day. The contractor and DOT were very pleased with the results.