Waynesville, North Carolina – May 22, 2017 – PREVent-C® technology, a proven shrinkage-reducing, and crack-control concrete admixture, was used in the accelerated construction techniques by the Georgia Department of Transportation (DOT) to repair the Interstate 85 bridge, which burned down on March 30, 2017.
Thomas Concrete, one of the leading suppliers of high-quality ready-mixed concrete in the Southeast, added PREVent-C® technology to its concrete mix to ensure an efficient construction timeline and a strong, effective bridge repair that would not require extensive and costly maintenance in the near future. C.W. Matthews Contracting Co., Inc., is the contractor leading the project.
John Cook, Director of Technical Services for Thomas Concrete commented he was pleased to be using a product that had no adverse effect on their process while providing such a positive result for the owner. Adam Grist, Vice President of Structures for C.W. Matthews, said his crews noticed no difference working with the product during the placement and commended Georgia DOT for embracing innovative technologies that improve the end product.
PREVent-C® technology was selected for the project because it blends expansive components with pore water surface tension reduction to successfully defend against cracks and increase the expected life of a bridge deck. It has been proven to reduce shrinkage by more than 90 percent, depending on the mix design and amount of PREVent-C utilized.
“Bridge decks are constructed from concrete for strength and durability. However, the durability of bridge decks are severely compromised by shrinkage cracks, which occur due to volume change caused by the drying process as well as other mechanisms,” said Jim Preskenis, Vice President of Sales for Premier Construction Products Group, makers of PREVent-C. “PREVent-C is used on any crack-critical structure or whenever there are shrinkage concerns.”
Shrinkage cracks provide water and deicing chemicals immediate access directly to the steel reinforcement and internal concrete of a bridge deck. Long-term, this leads to significant repairs and maintenance, and a need for a replacement well before the expected lifecycle of the structure.
The I-85 project required a very fast construction schedule due to the economic impact of the detour. Georgia DOT selected an accelerated mix and a 3-day curing period versus a more standard 7-day curing period. The selected mix design allowed for a shorter construction schedule leading to the much earlier than anticipated opening of the interstate.
“In a typical scenario when accelerated strength and minimal curing are used, cracking would be visible immediately following the end of curing,” said Preskenis. “On I-85 when the curing was removed, no cracking was observed.”
Prior to the repair of the I-85 bridge, the Georgia DOT used PREVent-C® as an admixture in three other bridge repair and maintenance projects. The result of using the technology in the concrete mix designs provided dramatic improvement versus the traditional concrete mix designs.
PREVent-C was developed by Premier Construction Products Group, a fully-owned division of Premier Magnesia LLC. Premier Magnesia is a global market leader in magnesia-based products and solutions for dozens of applications from agricultural to industrial and environmental markets. Premier Magnesia is one of the world’s principal manufacturers and suppliers of high purity calcined magnesium oxide and magnesium hydroxide products. Learn more at www.premiermagnesia.com/cpg.