Skip to contentUnited States Department of Transportation - Federal Highway Administration FHWA Home
Research Home   |   Pavements Home
REPORT
This report is an archived publication and may contain dated technical, contact, and link information
Publication Number: FHWA-HRT-05-038
Date: August 2006

 

Guide for Curing Portland Cement Concrete Pavements, II

PDF Version (768 KB)

PDF files can be viewed with the Acrobat® Reader®

FOREWORD

There has been a considerable amount of research over approximately the last 70 years on the theoretical aspects of curing portland cement concrete. Early work focused principally on portland cement hydration chemistry and the physics of developing microstructure. Later work incorporated features of pozzolanic reactions and other supplemental cementing materials. Because of this work, there is sufficient understanding of the theoretical aspects of the curing process for concretes of conventional proportions using conventional materials to develop effective practical application rules. The causes of when and where problems exist while curing portland cement concrete pavement may be because of changes in concrete technology that developed since the curing guidance was written or from some details of paving construction practice that differed from the types of concrete construction around which curing guidance was developed.

This report contains information on the current state of knowledge of curing hydraulic-cement concrete and on current curing practice, gathered by means of a literature review and a review of current standard guidance. A separate report (FHWA RD-02-099 Guide for Curing of Portland Cement Concrete Pavements, Volume. I) was published in January 2005 and captures the details of the recommended guidance.

Gary L. Henderson
Director, Office of Infrastructure
Research and Development

Notice

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document. This report does not constitute a standard, specification, or regulation.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear in this report only because they are considered essential to the objective of the document.

Quality Assurance Statement

The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

Technical Report Documentation Page

1. Report No.

FHWA-HRT-05-038

2. Government Accession No.

3. Recipient's Catalog No.

4. Title and Subtitle

Curing Portland Cement Concrete Pavements, Volume II

5. Report Date

August 2006

6. Performing Organization Code:

CEERD-SC-A

7. Author(s)

Toy S. Poole

8. Performing Organization Report No.

ERDC-CMB 05-021

9. Performing Organization Name and Address

Structures Laboratory
USAE Research and Development Center (ERDC)
3909 Halls Ferry Road
Vicksburg, MS 39180-6199

10. Work Unit No.

11. Contractor Grant No.

DTFH61-98-Y-50030

12. Sponsoring Agency Name and Address

Federal Highway Administration

6300 Georgetown Pike

McLean, VA 22101-2296

13. Type of Report and Period Covered

14. Sponsoring Agency Code

15. Supplementary Notes

Stephen Forster and Peter Kopac, Contracting Officer's Technical Representatives (COTR), HRDI-11

16. Abstract

Information on the current state of knowledge of curing hydraulic-cement concrete and on current curing practice was gathered by means of a literature review and a review of current standard guidance. From this information, a draft guide for curing hydraulic-cement concrete pavements was developed. Draft guidance was based around type of curing used (water added, water retention by sheet, or curing compound) and around temperature effects. As a result of review by the project technical advisory panel, additional information was gathered from existing sources on several subjects. Laboratory studies were conducted on topics for which information was needed but not currently available. The result of the investigation was a set of guidelines that focused particularly on attention to details of moisture retention and temperature immediately after placing (initial curing period) and on details of selection of materials for final curing and determining when to apply final curing. Test methods for evaluating application rate of curing compound and effectiveness of curing were also reported. A separate report (FHWA RD-02-099 Guide for Curing of Portland Cement Concrete Pavements, Volume I) has been written that captures the details of the recommended guidance. That report is intended to be the principal technology transfer medium.

17. Key Words

Curing, Portland cement concrete paving, curing compound, evaporation reducers, initial set, final set, plastic shrinkage

18. Distribution Statement

No restrictions. This document is available to the public through the National Technical Information Service, Springfield, Virginia 22161.

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this Page)

Unclassified

21. No of Pages

170

22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

SI (Modern Metric) Conversion Factors

TABLE OF CONTENTS

LIST OF FIGURES

Figure 1. Canopy used to protect fresh concrete.

Figure 2. General layout of the draft guide.

Figure 3. Selection among moist-curing methods.

Figure 4. Decision criteria for curing-compound methods.

Figure 5. Decision criteria for water-added methods.

Figure 6. Decision criteria for water-retentive methods other than those using curing compounds.

Figure 7. Decision criteria for duration of curing.

Figure 8. Decision criteria for temperature management in hot weather.

Figure 9. Decision criteria for temperature management in cold weather.

Figure 10. Calculated versus measured evaporation rates. Wind directly on the free-water surface.

Figure 11. Comparison of total water lost, expected from the ACI 308 nomograph and bleed rate of a 0.45 water-cement concrete.

Figure 12. Evaporation of water from a 0.37 water-cement specimen compared with the rate expected from the ACI 308 nomograph. Surface temperature changes approximately track evaporation rates.

Figure 13. Bleeding pattern of a 0.45 water-cement ratio concrete.

Figure 14. Bleeding rate per unit thickness of concrete (cm) versus water-cement ratio.

Figure 15. Development of spall as a result of early application of curing compound.

Figure 16. Cracked curing membrane resulting from application before cessation of bleeding.

Figure 17. Rebound number of concrete surface versus water loss in final curing period (7 days).

Figure 18. Surface water absorption versus water loss during the final curing period (7 days).

Figure 19. Water loss at 72 h versus application rate of curing compound. The more conventional representation of application rate (m2/L) is annotated by each point.

Figure 20. Surface water absorption versus application rate of curing compound.

Figure 21. Rebound number versus application rate of curing compound.

Figure 22. Comparison of calculated versus measured drying times for six curing compounds under a range of drying conditions.

Figure 23. Effect of curing compound application on concrete surface temperature.

Figure 24. Fresh mortar specimens with variable applications of white pigmented curing compound. The top four specimens contained 15.2, 7.9, 5.4, 3.2 m2/L (L to R). The bottom 3 specimens were treated as unknowns (see table 12).

Figure 25. Black construction-paper specimens with variable applications of white pigmented curing compound. The top four specimens contained 10.1, 7.5, 5.9, 4.5 m2/L (L to R). The bottom 3 specimens were treated as unknowns (see table 13).

Figure 26. Reflectance versus application rate for white pigmented curing compound applied to fresh mortar at different rates. Data points represented by open symbols were treated as unknowns.

Figure 27. Reflectance versus application rate for white pigmented curing compound applied to black-paper specimens at different rates. Data points represented by open symbols were treated as unknowns.

Figure 28. Effect of curing quality on development of rebound number at early ages. Specimens cured at 38 °C.

Figure 29. Effect of curing condition on rebound number of top surface of specimens at 7 days.

Figure 30. Correlation between rebound number and surface water absorption.

Figure 31. Surface water absorption versus depth for concrete cured with different methods.

Figure 32. Relationship between shrinkage of near-surface zone of concrete and water absorption after 11 days of exposure to drying conditions.

Figure 33. Relationship between maximum temperature gradient between concrete surface and 50 mm depth versus initial evaporation rate calculated form the ACI nomograph.

Figure 34. Temperature gradient in a 50-mm thick specimen starting at 44 °C, air temperature of 22 °C, RH of 29 percent, and windspeed of 4.6 m/s.

LIST OF TABLES

 


The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT).
The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT). Provide leadership and technology for the delivery of long life pavements that meet our customers needs and are safe, cost effective, and can be effectively maintained. Federal Highway Administration's (FHWA) R&T Web site portal, which provides access to or information about the Agency’s R&T program, projects, partnerships, publications, and results.
FHWA
United States Department of Transportation - Federal Highway Administration