Depending on mix design, latex-modified concrete (LMC) overlays made with portland cement can be reopened to traffic in 48 to 96 hours. To fast-track an overlay project on a bridge outside the state’s second largest city, PennDOT used a very-early-strength LMC (VESLMC) made with Rapid Set® cement instead. The overlay was ready for traffic after three hours.
The Holy Grail of concrete bridge deck maintenance is an easy-to-install, high-early-strength overlay for fast reopening and very low permeability for durability. North Carolina and Lanford Brothers try the latest option: Rapid Set® Cement dosed with Liquid Low-P™ (for “low permeability”) admixture.
Public agencies often fast-track bridge deck overlays by using Rapid Set® Cement in latex-modified concrete (LMC) mixes. In this case, Rapid Set® Latex-Modified Concrete (RSLMC) achieved a federal agency’s specified 2500 psi compressive strength requirement in 3 hours.
The specification called for a compressive strength of 3,000 psi prior to opening to traffic. The Rapid Set Latex-Modified Concrete overlay achieved this strength within three hours of placement, allowing the bridge to open for traffic each evening, meeting the DOT’s requirement. Product used was RSLMC.
Using a fast-setting Rapid Set Cement for a Latex Modified Concrete Overlay instead of Type III portland cement, allowed schedules to be met despite unexpected delays.
The cement used in concrete can have a lasting impact on the life span of new concrete bridge decks. Learn how Type K cement for new bridge construction and rapid hardening cement for repairs and new overlays can help extend the useful life cycle of concrete bridge decks.
Rapid Set Latex-Modified Concrete (RSLMC) overlay helped move the Lewis & Clark Bridge project ahead of schedule and under budget. WSDOT saved a minimum of nine days by using RSLMC instead of a slower setting concrete overlay. The repairs will extend the life of the bridge another 25 years.
Wider use of proven technologies that eliminate or reduce concrete cracking in old or new decks can reduce the billions of dollars spent annually in the United States on repair or replacement of bridge decks damaged by chloride-induced corrosion. Products used include Type K shrinkage-compensating cement and RSLMC.