4 chemical shrinkage - Oregon State University

AN ABSTRACT OF THE THESIS OF Tengfei Fu for the degree of Master of Science in Civil Engineering presented on February 15, 2011 Title: Autogenous Deformation and Chemical Shrinkage of High Performance Cementitious Systems

Abstract approved: d Dr. Jason H. Ideker

In the past ten years, renewed research interest has shown the benefits of internal curing by incorporating saturated lightweight fine aggregate (LWFA) in high performance concrete (HPC). As a result, the technology of internal curing has steadily progressed from laboratory studies to field applications. To determine the optimum LWFA content, information about the propensity for shrinkage in the cement paste, specifically the chemical shrinkage value, is needed. However, there is a lack of information on how to determine the ultimate chemical shrinkage value for HPC with supplementary cementitious materials (SCMs) and/or shrinkage reducing admixture (SRA). The purpose of this thesis was to identify a simple procedure to determine ultimate chemical shrinkage values for given concrete systems with SCMs and/or SRA. Modifications to the ASTM C1608 (Standard Test Method for Chemical Shrinkage of Hydraulic Cement Paste) were investigated up to a 14 day age. Neat paste (cement only), as well as binary and ternary systems, were measured to investigate the influence of SCMs and SRA on chemical shrinkage. Based on the observed data, an experimental prediction model was adopted and verified to estimate ultimate chemical shrinkage values for portland cement systems containing SCMs and/or SRA. The model agreed well with the obtained data and simplified the existing method of determining the ultimate chemical shrinkage value.

iv

Another purpose of this research was to investigate the effect of SCMs and SRA on autogenous deformation of HPC for which a buoyancy method was used. The findings provided insight into the mechanisms behind autogenous shrinkage and effective strategies to reduce autogenous shrinkage.

Calcium aluminate cements (CACs) were also investigated as part of this research project as a rapid repair material for applications, such as high performance concrete bridge decks. Chemical shrinkage and autogenous deformation of CAC binders were tested in a similar manner to the OPC systems in this study. It was observed that GCX paste cured isothermally at 38 °C exhibited expansion with a particular shape of chemical shrinkage development curve. An X-ray diffraction suggested that the expansion might be related to the conversion process indicating that chemical shrinkage may be used as a predictor of conversion processes for CAC systems in isothermal condition.

v

© Copyright by Tengfei Fu February 15, 2011 All Rights Reserved

Autogenous Deformation and Chemical Shrinkage of High Performance Cementitious Systems

by Tengfei Fu

A THESIS

submitted to

Oregon State University

in partial fulfillment of the requirements for the degree of

Master of Science

Presented February 15, 2011

Commencement June 2011

Master of Science thesis of Tengfei Fu presented on February 15, 2011.

APPROVED:

d Major Professor, representing Civil Engineering

d Head of the School of Civil & Construction Engineering

d Dean of the Graduate School

I understand that my thesis will become part of the permanent collection of Oregon State University libraries. My signature below authorizes release of my thesis to any reader upon request.

d

Tengfei Fu, Author

ACKNOWLEDGEMENTS First and foremost, I would like to thank my advisor Dr. Jason H. Ideker. Without your sincere assistance, support and patience, none of this thesis would come into existence. I am truly appreciated for every effort you put in for me over the years. You are more than an advisor to me. You are also my mentor, my friend, and an example to follow. I also would like to thank Dr. David Trejo, Dr. Michael H. Scott and Dr. Lech Muszyński for their service as my committee members. All your comments and questions are well appreciated. I would like to thank all my colleagues and friends, Dr. Thomas Schumacher, Nicholas Tymvios, Tyler Deboodt, Kelsea Schwing, Shweta Keshari, Juan Zheng, Meng Li, Yisen Guo, Minjie Zhu, Wei Wang and Michael Johnson, for such a pleasant grad school experience. And a special thanks to Oregon Department of Transportation for funding this project and providing further research opportunities. Last, but far from least, I would like to thank my parents for the unconditional love and support all through the years. Thank you for always believing in me and encouraging me to chase my dreams. Also, I owe a great deal of gratitude to my fiancée, Miss Lu. Without your encouragement, patience and selfless sacrifices, I could never be the person I am.

iii

CONTRIBUTION OF AUTHORS Tyler Deboodt, fellow graduate student, was involved in the writing of Chapter 2.

TABLE OF CONTENTS Page 1

INTRODUCTION ...................................................................................................... 1 1.1 1.2 1.3 1.4

2

INTERNAL CURING ................................................................................................ 1 CHEMICAL SHRINKAGE AND INTERNAL CURING ................................................... 2 RESEARCH SCOPE ................................................................................................. 4 NOMENCLATURE .................................................................................................. 6

LITERATURE REVIEW ........................................................................................... 7 2.1 HIGH PERFORMANCE CONCRETE ......................................................................... 7 2.1.1 Ordinary Portland Cement with SCMs ........................................................... 8 2.1.2 Calcium Aluminate Cements ........................................................................ 11 2.2 CHEMICAL SHRINKAGE ...................................................................................... 12 2.2.1 Introduction ................................................................................................... 12 2.2.2 Test Method .................................................................................................. 13 2.3 AUTOGENOUS DEFORMATION ............................................................................ 18 2.3.1 Introduction ................................................................................................... 18 2.3.2 Linear Measurements of Autogenous Deformation ...................................... 25 2.3.3 Other Measurement Methods of Autogenous Strain .................................... 32 2.3.4 Comparison and Summary ............................................................................ 34 2.3.5 Mitigation Strategies ..................................................................................... 37 2.4 PLASTIC SHRINKAGE .......................................................................................... 38 2.4.1 Introduction ................................................................................................... 38 2.4.2 Mechanisms of Plastic Shrinkage ................................................................. 38 2.4.3 Predicting Evaporation.................................................................................. 39 2.4.4 Test Methods ................................................................................................. 41 2.4.5 Mitigation Strategies ..................................................................................... 42 2.5 DRYING SHRINKAGE .......................................................................................... 44 2.5.1 Introduction ................................................................................................... 44 2.5.2 Drying Shrinkage Test Methods ................................................................... 45 2.5.3 Mitigation Strategies ..................................................................................... 49 2.6 SUMMARY .......................................................................................................... 54

3

MATERIALS AND METHODS .............................................................................. 55 3.1 MATERIALS ........................................................................................................ 55 3.1.1 Cements......................................................................................................... 55 3.1.2 SCMs............................................................................................................. 56 3.1.3 SRA ............................................................................................................... 56 3.2 TESTING METHODS ............................................................................................ 57 3.2.1 Paste Mixing Procedure ................................................................................ 57 3.2.2 Chemical Shrinkage Testing Procedure ........................................................ 57 3.2.3 Autogenous Deformation Testing Procedure................................................ 59 3.3 PASTE TESTING MATRIX ................................................................................... 60

iv

TABLE OF CONTENTS (CONTINUED) Page 4

CHEMICAL SHRINKAGE...................................................................................... 62 4.1 OPC RESUTLS AND ANALYSIS............................................................................ 63 4.1.1 Prediction Model ........................................................................................... 67 4.1.2 Recommended Modification on Procedure for Determining Chemical Shrinkage Value ........................................................................................................ 70 4.1.3 Factors Influence Chemical Shrinkage ......................................................... 73 4.1.4 Summary ....................................................................................................... 81 4.2 CAC RESUTLS AND ANALYSIS .................................................................. 82 4.2.1 Conversion in CAC Systems ........................................................................ 83 4.2.2 Chemical Shrinkage and XRD Analysis on GCX ........................................ 86 4.2.3 Chemical Shrinkage on Expansive Cementitious Systems ........................... 91 4.3 CONCLUSIONS .................................................................................................... 93

5

AUTOGENOUS DEFORMATION ......................................................................... 94 5.1 OPC RESUTLS AND ANALYSIS............................................................................ 95 5.1.1 Setting Time .................................................................................................. 95 5.1.2 Effect of Water to Cement Ratio .................................................................. 97 5.1.3 Effect of SCMs ............................................................................................. 99 5.1.4 Effect of SRA.............................................................................................. 101 5.2 CAC RESUTLS AND ANALYSIS ......................................................................... 102 5.2.1 Setting Time ................................................................................................ 102 5.2.2 Results and Analysis ................................................................................... 103 5.3 CONCLUSIONS .................................................................................................. 104

6

CONCLUSIONS..................................................................................................... 106 6.1 6.2 6.3

SUMMARY ........................................................................................................ 106 CONCLUSIONS .................................................................................................. 107 FUTURE WORK ................................................................................................. 108

BIBLIOGRAPHY ........................................................................................................... 109 APPENDIX A : MATERIAL CERTIFICATES ........................................................... 118 APPENDIX B : CHEMICAL SHRINKAGE TEST RESULTS ................................... 123 B.1 B.2 B.3

OPC CS TEST RESULTS .................................................................................... 123 OPC 14 DAY CS DATA SHEETS ........................................................................ 125 OPC CS TEST RESULTS (FITTED) ..................................................................... 128

LIST OF FIGURES Figure

Page

2.1: Chemical shrinkage measurement methods (Bouasker et al. 2008) ......................... 13 2.2: Automated chemical shrinkage test set-up ............................................................... 15 2.3: Typical automated chemical shrinkage results (Ideker 2008) .................................. 16 2.4: Chemical shrinkage results by hand (Ideker 2008) .................................................. 16 2.5: An illustration of the experimental chemical shrinkage set-up (Sant et al. 2006).... 17 2.6: Illustration of the collapse of a small capillary (Φ