Volume 35, Issue 6 (November 2007)
A Very Early Strength Concrete for Highway Construction
The purpose of this research study was to develop an improved very early strength (VES) concrete mix for highway construction. More than 50 concrete mixes were evaluated for strength, shrinkage, and curing rate (maturity), eventually leading to the development of an optimized VES concrete mix with improved performance characteristics. The new mix, which is detailed in the paper, can gain strength more reliably than the former standard New Jersey Department of Transportation (NJDOT) VES mix, reaching a flexural strength of 350 psi (2.4 MPa) in less than 6.5 h. The improved mix also exhibited 79 to 93 % less shrinkage. The study found that maintaining an initial mix temperature of 28°C (82°F) is crucial to attain target strengths.