The curing of concrete is widely recognized as a critical step for achieving high-quality long-lasting concrete pavements. While the most common curing practice is the application of membrane-forming curing compounds, the compound specifications, including application rates and the quality control/quality assurance (QC/QA) practice, differ among state departments of transportation (DOTs). The timing of the curing application—which is critical to the success of the curing process—also differs among DOTs. State DOTs may also adopt additional curing measures during adverse weather conditions.
The objective of this synthesis is to document state DOT practices for curing pavement concrete including procedures, materials, application rates, timing, QC/QA procedures, and specific measures adopted when paving under adverse weather conditions. The synthesis includes concrete pavement overlays, inlays, and widenings.
Information to be gathered includes (but is not limited to):
• Extent of DOT use of concrete pavements (e.g., lane miles, volume of concrete used, use in last five years);
• Curing procedures allowed by DOT specifications;
• Curing materials types used (e.g., curing compounds) and specifications;
• Application rates and details;
• Pre-certification process (e.g., in-house, NTPEP);
• How the timing of the curing is established, including objective (e.g., tests) and subjective evaluations (e.g., sheen of the concrete surface);
• Pre-construction evaluation of curing (e.g. test strips, trial slabs);
• Approaches followed to ensure the specified application of the curing (QA);
• Use of support software;
• Use of sensors (e.g. temperature, internal relative humidity, etc.) to aid curing procedure or QA evaluation;
• QC requirements in specifications;
• Weather conditions under which concrete paving is permitted;
• Additional curing measures required when paving under adverse weather conditions; and
• Procedures taken if early age cracking (including plastic shrinkage cracking) is observed.
Information will be gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected agencies for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified.
Information Sources (Partial):
• Taylor, P. C., van Dam, T. J., Sutter, L. L., and Fick, G. J. (2019). Integrated Materials and Construction Practices for Concrete Pavement: A State-of-the-Practice Manual. Second Edition. National Concrete Pavement Technology Center, Iowa State University, Ames, IA.
• Curing Concrete Paving Mixtures. (2018). FHWA Tech Brief. FHWA-HIF-18-015. FHWA, U.S. Department of Transportation.
• Guide to External Curing of Concrete. (2016). ACI 308R-16. American Concrete Institute, Farmington Hills,MI.
• Guide to Cold Weather Concreting. (2016). ACI 306R-16. American Concrete Institute, Farmington Hills,MI.
• Ruiz, J. M., Garber, S., and Dick, J. C. (2015). Computer-Based Guidelines for Concrete Pavements. HIPERPAV IIIⓇ, Version 3.3 User's Manual. FHWA-HRT-14-087. FHWA, U.S. Department of Transportation.
• Guide to Hot Weather Concreting. (2010). ACI 305R-10. American Concrete Institute, Farmington Hills,MI.
• Early Cracking of Concrete Pavement-Causes and Repairs. (2002). American Concrete Pavement Association, Washington, D.C.
• Taylor, P. C. (2014). Curing Concrete. CRC Press, Boca Raton, FL.
Jo Allen Gause
First Panel: October 5, 2021, virtual
Teleconference with Consultant: October 29, 2021, 2:30 p.m. ET
Second Panel: June 16, 2022, Washington, DC
Patricia Baer, Pennsylvania Department of Transportation
Dulce Rufino Feldman, California Department of Transportation
M. Shabbir Hossain, Virginia Department of Transportation
Daniel Miller, Ohio Department of Transportation
Andy Naranjo, Texas Department of Transportation
Peter Taylor, National CP Tech Center, ISU
Michael Praul, Federal Highway Administration
Nancy Whiting, Transportation Research Board