Determination of Acceptance Permeability Characteristics for Performance-Related Specifications for Portland Cement Concrete Final Report Submitted to Florida Department of Transportation (Contract No. BC 354-41) BY Abdol R. Chini, Larry C. Muszynski, and Jamie Hicks M.E. Rinker, Sr. School of Building Construction University of Florida Gainesville, FL 32611 July 2003 Determination of Acceptance Permeability Characteristics for Performance-Related Specifications for Portland Cement Concrete This report is prepared in cooperation with the State of Florida Department of Transportation and the U.S. Department of Transportation. The opinions, findings and conclusions expressed in this report are those of the authors and not necessarily those of the State of Florida Department of Transportation or the U.S. Department of Transportation. Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. 4. Title and Subtitle 5. Report Date Determination of Acceptance Permeability Characteristics July 11, 2003 for Performance-Related Specifications for Portland Cement Concrete 6. Performing Organization Code 7. Author’s 8. Performing Organization Report No. Abdol R. Chini, Larry C. Muszynski, Jamie K. Hicks 9. Performing Organization Name and Address 10. Work Unit (TRAIS) M.E. Rinker, Sr. School of Building Construction University of Florida RNK 304, PO Box 115703 11. Contract or Grant No. Gainesville, FL 32611 BC 354-41 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Florida Department of Transportation Final (March 20, 2001 to June 15, 2003) 605 Suwannee Street Tallahassee, FL 32399-0450 14. Sponsoring Agency Code 15. Supplementary Notes Prepared in cooperation with the U.S. Department of Transportation. 16. Abstract The concrete strength has been measured for a long time; however, it is becoming increasingly desirable to the Florida Department of Transportation (FDOT) to have the ability to measure concrete’s durability in addition. One test to assess durability of concrete is the Rapid Chloride Permeability (RCP) test. This test records the amount of charge passed through a sample in order to evaluate its permeability. The FDOT has the desire to make the transition from a prescriptive specification style to a performance-based specification. This research project consists of the determination of the RCP values of all classes of concrete that are specified in FDOT specifications. This goal was accomplished by taking concrete test cylinders from projects that were under construction during the study. Samples are divided by FDOT concrete class and then by composition, specifically their pozzolanic additives, for evaluation. Test value recommendations are made according to these categories. The RCP test has been around for approximately 20 years and is widely used. However, the test is labor intensive and therefore costly. For this reason, an alternative Non Destructive Test (NDT) called the Surface Resistivity test is being evaluated as a possible replacement. The Surface Resistivity test uses a Wenner 4-probe array and a small alternating current to make instantaneous readings. The readings are returned by a data acquisition unit as an indication of the concrete’s ability to conduct current. This project also applied this test to the samples in order to reveal a relationship between the two tests (i.e. RCP and Surface Resistivity test) of which a good correlation has been shown. Values for Surface Resistivity as well as a table to aid in the interpretation of results have been provided. Lastly, recommendations for RCP test improvement are suggested in order to improve on the test until an appropriate alternative is arrived at and agreed upon. 17. Key Words 18. Distribution Statement Concrete Durability, Permeability, No restriction This report is available to the public through the National Technical Information Performance-based Specifications Service, Springfield, VA 22161 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 162 ABSTRACT The concrete strength has been measured for a long time; however, it is becoming increasingly desirable to the Florida Department of Transportation (FDOT) to have the ability to measure concrete(cid:146)s durability in addition. One test to assess durability of concrete is the Rapid Chloride Permeability (RCP) test. This test records the amount of charge passed through a sample in order to evaluate its permeability. The FDOT has the desire to make the transition from a prescriptive specification style to a performance- based specification. This research project consists of the determination of the RCP values of all classes of concrete that are specified in FDOT specifications. This goal was accomplished by taking concrete test cylinders from projects that were under construction during the study. Samples are divided by FDOT concrete class and then by composition, specifically their pozzolanic additives, for evaluation. Test value recommendations are made according to these categories. The RCP test has been around for approximately 20 years and is widely used. However, the test is labor intensive and therefore costly. For this reason, an alternative Non Destructive Test (NDT) called the Surface Electrical Resistivity test is being evaluated as a possible replacement. The Surface Electrical Resistivity test uses a Wenner 4-probe array and a small alternating current to make instantaneous readings. The readings are returned by a data acquisition unit as an indication of the concrete(cid:146)s ability to conduct current. This project also applied this test to the samples in order to reveal a relationship between the two tests (i.e. RCP and Surface Resistivity test) of which a good correlation has been shown. Values for Surface Resistivity as well as a table to aid in the interpretation of results have been provided. i Lastly, recommendations for RCP test improvement are suggested in order to improve on the test until an appropriate alternative is arrived at and agreed upon. ii ACKNOWLEDGMENTS The research reported here was sponsored by the Florida Department of Transportation. Sincere thanks are due to Mike Bergin, P.E., State Structural Materials Engineer, State Materials Office in Gainesville, Florida for his guidance, support, and encouragement. Special thanks to Charles Ishee, Structural Materials Engineer and Ghulam Mujtaba, Concrete Materials Engineer, State Materials Office in Gainesville, Florida for their guidance and contribution made during the course of the project, and for their review of this report and helpful suggestions. Sincere appreciation is due to Mario Paredes, of the FDOT State Materials Office Corrosion Lab for countless hours of discussion as well as technical support throughout the project. Math McNally, Matt Taylor, Brandi Tait, Wayne Sinclair, and Charlotte Kasper ran testing, and without their help this project would never have completed. We thank them for the accuracy and level of professionalism they brought to the project. Tim Ruelke was instrumental in coordinating tests performed in the FDOT Materials Lab in Lake City for comparing results from two laboratories. His active participation in this project is appreciated. iii TABLE OF CONTENTS page ABSTRACT.........................................................................................................................i Abstract................................................................................................................................i ACKNOWLEDGMENTS.................................................................................................iii LIST OF TABLES............................................................................................................vii LIST OF FIGURES...........................................................................................................ix INTRODUCTION...............................................................................................................1 LITERATURE REVIEW....................................................................................................3 Physical Factors..............................................................................................................5 Environmental..........................................................................................................5 Design......................................................................................................................7 Operational.............................................................................................................12 Micro-Level of Concrete...............................................................................................13 Pore Structure.........................................................................................................13 Pore Water Composition........................................................................................15 Mix Design Factors.......................................................................................................17 Water-Cement Ratio..............................................................................................19 Curing Conditions..................................................................................................20 Type of Cement and Pozzolanic Admixtures........................................................21 Air-Entraining Agents............................................................................................24 Measurement Methods of Concrete Durability.............................................................25 Chloride/ Salt-Ponding Test...................................................................................26 Rapid Chloride Permeability Test..........................................................................26 Migration Cells......................................................................................................31 Surface Electrical Resistivity Test.........................................................................32 METHODOLOGY............................................................................................................44 Rapid Chloride Permeability Test.................................................................................44 Sample Preparation................................................................................................44 Pre-test Requirements............................................................................................46 Run Test and Collect Data.....................................................................................47 Clean Up................................................................................................................49 Surface Resistivity Test................................................................................................51 iv DATA PRESENTATION..................................................................................................54 Sample...........................................................................................................................54 Sample Population........................................................................................................54 Concrete Classes....................................................................................................54 Class of Concrete No of Sets of samples...........................................................56 Geographic Districts..............................................................................................56 Concrete Mix Designs............................................................................................58 Samples with High RCP Values............................................................................59 Class II..........................................................................................................................61 Rapid Chloride Permeability Test..........................................................................61 Surface Resistivity.................................................................................................61 Class II Bridge Deck.....................................................................................................67 Rapid Chloride Permeability Test..........................................................................67 Surface Resistivity Test..........................................................................................68 Correlation between RCP and Surface Resistivity Results....................................68 Class IV.........................................................................................................................73 Rapid Chloride Permeability Test..........................................................................73 Surface Resistivity.................................................................................................75 Correlation between RCP and Surface Resistivity.................................................76 Class IV Drilled Shaft...................................................................................................82 Rapid Chloride Permeability Test..........................................................................82 Surface Resistivity Test..........................................................................................83 Correlation between RCP and Surface Resistivity Test Results............................83 Class V..........................................................................................................................89 Sample....................................................................................................................89 Rapid Chloride Permeability Test..........................................................................89 Surface Resistivity.................................................................................................89 Correlation between RCP and Surface Resistivity Test Results............................90 Class V Special.............................................................................................................92 Rapid Chloride Permeability Test..........................................................................92 Surface Resistivity.................................................................................................92 Correlation between RCP and Surface Resistivity Test Results............................94 Class VI.........................................................................................................................98 Rapid Chloride Permeability Test..........................................................................98 Surface Resistivity.................................................................................................98 Correlation between RCP and Surface Resistivity Test Results............................99 Comparing Results from Two Laboratories...............................................................100 RCP Test Results using Alternative Methods to Seal Samples..................................101 Spray Alternative to Seal RCP Samples..............................................................102 Tape Alternative to Seal RCP Samples................................................................103 CONCLUSIONS..............................................................................................................105 Individual Concrete Class Recommendations............................................................105 Recommended Values at Different Confidence Levels.......................................106 Recommendation.................................................................................................113 RCP test Standard Limit Drawbacks...................................................................114 v RCP / Surface Resistivity............................................................................................115 Testing Procedure Improvements...............................................................................118 MASTER LIST OF SAMPLE DATA.............................................................................119 LIST OF REFERENCES.................................................................................................149 vi LIST OF TABLES Table page Table 4.1 Specified Compressive Strength of FDOT Concrete Classes...........................54 Table 4.2 Sampling Distribution from each Class of Concrete........................................56 Table 4.3 Sample Distributions Across FDOT Districts...................................................56 Table 4.4 AASHTO Table Guiding RCP Test Value Interpretation................................59 Table 4.5 Failed Samples by Class...................................................................................60 Table 4.6 RCP and Surface Resistivity Test Results of Class II Concrete.......................62 Table 4.7 The RCP and Surface Resistivity Results of Class II Bridge Deck..................67 Table 4.8 RCP and Surface Resistivity Test Result of Class IV Concrete Samples........74 Table 4.9 RCP and Surface Resistivity Test Result of Class IV DS Concrete Samples..82 Table 4.10 RCP and Surface Resistivity Test Result of Class V Concrete Samples........89 Table 4.11 RCP and Surface Resistivity Test Result of Class V S Concrete Samples.....93 Table 4.12 RCP and Surface Resistivity Test Result of Class VI Concrete Samples......98 Table 4.13 Comparing Statistical Results of RCP test from Two Laboratories.............101 Table 4.14 Comparing Qualities of Epoxy, Spray, and Tape Methods..........................104 Table 5.1 Recommended Allowable RCP and Surface Resistivity Values for Class II.107 Table 5.2 Recommended Allowable RCP and SR for Class II Bridge Deck.................108 Table 5.3 Recommended Allowable RCP and SR Values for Class IV.........................109 Table 5.4 Recommended Allowable RCP and SR Values for Class IV Drilled Shaft...110 Table 5.5 Recommended Allowable RCP and Surface Resistivity Values for Class V.111 Table 5.6 Recommended Allowable RCP and SR Values for Class V Special.............112 vii
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