The Maturity Concept for Early Opening of Concrete Pavements – The Underutilized Opportunity

AUTHORS: Grove, J.; Praul, M.; Gudimettla, J.; and Conway, R., Wathne, L.G.

ABSTRACT: The maturity method for determining early strength of concrete nondestructively has been available for decades. FHWA has been demonstrating this technology through what is now called the Mobile Concrete Technology Center (MCTC), since the late 1980’s. Some state agencies have adopted maturity testing into their standard specifications to accelerate construction. While maturity is an option in many states specifications it hasn't seen widespread use because the specifications are too complicated and not field friendly. What is needed is a maturity procedure specifically for concrete paving that is easier to implement. The Iowa DOT in 1997 began allowing opening to traffic strength to be estimated with a simpler procedure of maturity testing. It has been used extensively for over 25 years as a contractor option specification. No pavement cracks or failures have been reported over those years due to traffic driving on pavement when it had inadequate strength. This paper outlines a simplified approach for the use of maturity to monitor early age strength in paving concrete. This procedure is easy to implement by the contractor and was the key to its widespread adoption by contractors in Iowa. It is also beneficial to the agency in numerous of ways. This paper also includes a discussion of the barriers that have restricted wider use in the past. The advantages offered by a modernized and simpler approach will be explained. New technologies for monitoring strength development are also presented.