The Specific Surface of Hardened Portland Cement Paste as Measured by Low-Angle X-Ray

172 Pages·2012·5.71 MB·English

by  Douglas Windslow

THE SPECIFIC SURFACE OF HARDENED PORTLAND
CEMENT PASTE AS MEASURED BY LOW-ANGLE
X-RAY SCATTERING
AUGUST 1973 - NUMBER 15
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BY
WINSLOW
D.N.
JOINT HIGHWAY RESEARCH PROJECT
PURDUE UNIVERSITY AND
INDIANA STATE HIGHWAY COMMISSION

Final Report
THE SPECIFIC SURFACE OF HARDENED PORTLAND CEMENT PASTE
AS MEASURED BY LOW-ANGLE X-RAY SCATTERING
TO: J. F. McLaughlin, Director August 29, 1973
Joint Highway Research Project
FROM: H. L. Michael, Associate Director
Joint Highway Research Project File: 5-14-5
Attached 1s a Final Report titled "The Specific Surface
of Hardened Portland Cement Paste as Measured by Low-Angle
X-Ray Scattering". It has been authored by Mr. Douglas N.
Wlnslow, a Graduate Instructor 1n Research on our staff
during the conduct of the Study and was financed by the Purdue
Research Foundation. Mr. Wlnslow also used the research
report as his thesis for the Ph.D. degree.
As this research 1s closely related to other research
being supported 1n the area by the Indiana State Highway
Commission and the Federal Highway Administration 1t 1s
reported to the Advisory Board for Information.
Respectfully submitted,
Harold L. Michael
Associate Director
HLM:ms
cc w. L. Dolch R. H. Harrell C. F. Scholer
R. L. Eskew M. L. Hayes M. B. Scott
G. D. Gibson C. W. Lovell J. A. Spooner
W. H. Goetz G. W. Marks N. W. Stelnkamp
M. J. Gutzwi 1 ler R. D. Miles H. R. J. Walsh
G. K. Hallock G. T. Satterly E. J. Yoder
Final Report
THE SPECIFIC SURFACE OF HARDENED PORTLAND CEMENT PASTE
AS MEASURED BY LOW-ANGLE X-RAY SCATTERING
by
Douglas N. Winslow
Graduate Instructor 1n Research
Joint Highway Research Project
File No.: 5-14-5
The Research Reported Herein was Financed
By
the Purdue Research Foundation
Purdue University
West Lafayette, Indiana
August 29, 1973
Ill
ACKNOWLEDGMENTS
The author wishes to express his appreciation for the
continual guidance and support of his major professor,
Dr. Sidney Diamond, without which this research would not
have been possible. He also wishes to thank the other
members of his advisory committee, Dr. W. L. Dolch, Dr.
G. L. Liedl and Dr. R. W. Vest, for their assistance.
Dr. L. E. Copeland of the Portland Cement Association
provided early assistance and encouragement for which the
author is very grateful.
A great amount of scientific and technical help was
received from several other sources. The author wishes to
extend his appreciation to Dr. 0. Kratky, Dr. G. Porod and
Dr. H. Leopold of the University of Graz Austria, and
,
Dr. J. Cohen of Northwestern University for their time
consuming and patient answering of his many many questions.
The difficult and time consuming electronic alterations to
the X-ray equipment carried out by Mr. Nicholas Coburn
were invaluable to this research.
The assistance of Mrs. Carolyn Brendel and Mr. Richard
Burns in making many laboratory measurements is gratefully
acknowledged.
IV
TABLE OF CONTENTS
Page
LIST OF TABLES vi
LIST OF FIGURES viii
ABSTRACT ix
INTRODUCTION
1
LOW-ANGLE X-RAY SCATTERING THEORY 11
EXPERIMENTAL PROCEDURES
2
Materials 20
....
Preparation of Cement and Alite Pastes 20
Preparation of X-Ray Scattering Samples
of Cement Paste 21
Drying of the Cement Paste Samples 23
Special Treatments 25
Preparation of Samples Other Than Cement Paste 27
X-Ray Apparatus and Modifications 28
X-Ray Intensity Measuring Strategy 37
Parasitic Scatter 44
Sample Porosity 4 8
Sorption Measurements 53
X-RAY SCATTERING DATA 59
X-RAY SCATTERING CORRECTIONS AND CALCULATIONS 65
. .
RESULTS 84
Illite and Activated Charcoal 84
...
Tests on Mature, w/c = 0.4 Cement Pastes 84
DISCUSSION 92
Cement Paste Microstructure 92
Vapor Sorption and X-Ray Surface
Area Comparisons 92
Effect of Drying Saturated Cement Paste 94
... ..
Surface Area of Saturated Cement Paste 95
Effect of Progressive Drying of Cement Paste 98
Digitized by the Internet Archive
in 2011 with funding from
LYRASIS members and Sloan Foundation; Indiana Department of Transportation
http://www.archive.org/details/specificsurfaceoOOwind
TABLE OF CONTENTS, cont.
Page
...
Effect of Resaturation of Cement Paste 99
Effect of Heating Cement Paste 101
Surface Area of Alite Paste 102
Effect of Degree of Hydration 102
General Matter of Interpretation of X-Ray
Scattering Results 104
Reproducibility of X-Ray Scattering
Measurements 104
Comparison of Sorption and X-Ray Scattering
Results on Illite Clay and Activated Charcoal 105
Interpretation of Guinier's Law 107
Sensitivity of Porod Method to Small
Surface Separations Ill
CONCLUSIONS 113
LIST OF REFERENCES 115
APPENDICES
Appendix A 117
Appendix B 119
Appendix C 124
Appendix D 131
VITA 148
s
.
VI
LIST OF TABLES
Table Page
1. Physical Parameters and Calculated Porosities
for All Cement Paste Samples 54
2 Raw X-Ray Scattering Data Direct from X-Ray
Machine 61
3. Raw X-Ray Scattering Data Direct from X-Ray
Machine 62
4. Total and Parasitic Scattering Curves after
Combination of Multiple Scans 67
5. Values for Guinier Plot 70
....
6. Extrapolated Values from Guinier Plot 72
7. Calculations for Initial Porod Plot 74
8. Non-Interfacial Scatter Corrections to
Porod Plot 77
9. Very-Large-Angle Extrapolation of Porod
'
Invariant
79
10. Complete, Corrected Listing of Scattered
Intensities 80
11. Calculation of Porod 1 s Invariant 82
12. Specific Surface of Illite Clay and
Activated Charcoal 85
13. Results of Drying Cement Paste 86
....
14. Results of Resaturating Cement Paste 87
15. Results of Heating Cement Paste 87
16. Surface Area of Other w/s = 0.4 Cement Pastes 89
17. Surface Area of Different w/c Cement Pastes 90
.
Vll
LIST OF TABLES, cont.
Table Page
18. Comparison of Specific Surfaces Measured by
X-Ray Scattering and Vapor Sorption Techniques 107
19. "Average" Guinier Law Pore Size of Cement
Pastes 110
Appendix
Tables
20. Laboratory Report of Purdue Lab Cement
No. 317 117
21. Analysis of Alite Cement 118
22. Optimum Thickness of Cement Paste Samples
for X-Ray Scattering with Mo Ka Radiation 122
. .
23. Observed and Dead Time Corrected X-Ray
Intensities 130
24. Index to X-Ray Scattering Data Listed in
Table 25 131
25. Complete Listing of Scattering Test Data 133
. .