ASSESSMENT OF THE COEFFICIENT OF THERMAL EXPANSION OF ALABAMA CONCRETE ...

213 Pages·2008·2.49 MB·English

by  Kwame Opare

ASSESSMENT OF THE COEFFICIENT OF THERMAL EXPANSION OF
ALABAMA CONCRETE

Except where reference is made to the work of others, the work described in this thesis is
my own or was done in collaboration with my advisory committee. This thesis does not
include proprietary or classified information.

Kwame Opare Sakyi-Bekoe

Certificate of Approval:

Robert W. Barnes Anton K. Schindler, Chair
James J. Mallett Associate Professor Gottlieb Associate Professor
Civil Engineering Civil Engineering

Mary L. Hughes George T. Flowers
Instructor Interim Dean
Civil Engineering Graduate School
ASSESSMENT OF THE COEFFICIENT OF THERMAL EXPANSION OF
ALABAMA CONCRETE

Kwame Opare Sakyi-Bekoe

A Thesis

Submitted to

the Graduate Faculty of

Auburn University

in Partial Fulfillment of the

Requirements for the

Degree of

Master of Science

Auburn, Alabama
December 19, 2008
ASSESSMENT OF THE COEFFICIENT OF THERMAL EXPANSION OF
ALABAMA CONCRETE

Kwame Opare Sakyi-Bekoe

Permission is granted to Auburn University to make copies of this thesis at its discretion,
upon requests of individuals or institutions and at their expense. The author reserves all
publication rights.

Signature of Author

Date of Graduation

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VITA

Kwame Opare Sakyi-Bekoe, son of Dr. Kofi Sakyi-Bekoe and Madam Comfort
Prempeh, was born on December 22, 1973, at Akwatia, Ghana. He is a 1992 graduate of
Okuapemman Secondary School in Akropong-Akuapem, Ghana. He attended University
of Science and Technology, Kumasi in Ghana where he earned a Bachelor of Science
degree in Civil Engineering in February 1999. Upon completion of his undergraduate
course work, he practiced as a Civil/Structural Engineer before entering graduate school
at Auburn University with the intent of earning the degree of Master of Science in Civil
Engineering.

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THESIS ABSTRACT

ASSESSMENT OF THE COEFFICIENT OF THERMAL EXPANSION OF
ALABAMA CONCRETE

Kwame Opare Sakyi-Bekoe

Master of Science, December 19, 2008
(B.Sc.Civil Engineering, University of Science and Technology 1998)

213 Typed Pages

Directed by Anton K. Schindler

The coefficient of thermal expansion (CTE) is a fundamental property of portland
cement concrete. It represents the change in unit length of concrete per degree of
temperature change. The CTE is a very important property in concrete pavement design
and in the design of integral structures, especially bridge decks, as it can affect early-age
cracking, the serviceability, and performance of these concrete structures.
The increasing recognition of the potential magnitudes of thermal movements and
stresses induced in integral structures, especially bridge decks, and in pavements exposed
to the daily ambient temperature, suggest the need for a realistic CTE rather than an
assumed value for use in their design. The prime purpose of this research work was to
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quantify the CTE for concretes made with commonly used coarse aggregate types in the
Alabama concrete industry.
A total of fifty-four concrete samples were tested for their CTEs using the
Association of the American State Highways and Transportation Officials (AASHTO) TP
60 (2004) test method at a concrete age of 28 days. The concrete was made of three
different coarse aggregate types. The coarse aggregate types used were siliceous river
gravel, granite, and dolomitic limestone. Three different sand-aggregate ratios of 0.40,
0.45, and 0.50 as well as water-cement ratios of 0.32, 0.38, and 0.44 were used. Thus for
each coarse aggregate type, a total of nine concrete mixtures were made and a total of
eighteen concrete samples were tested for their CTEs using concrete cylinders of size 4
in.(diameter) x 7 in.(height) (100 mm x 175 mm). The CTEs were calculated for each
concrete sample in accordance with the procedure outlined in AASHTO TP 60 (2004).
The results showed that concretes made with siliceous river gravel have the
highest CTEs with an average value of 6.95 x 10-6 /oF (12.51 x 10-6 /oC) while those made
of granite have lower values, with an average of 5.60 x 10-6 /oF (10.08 x 10-6 /oC). The
lowest CTEs were observed for concretes made with dolomitic limestone, which had an
average value of 5.52 x 10-6 /oF (9.93 x 10-6 /oC).
It was determined for the materials tested that the sand-aggregate ratio and water-
cement ratio did not have as much influence on the concrete CTE as does the coarse
aggregate type. An increase in the volume of the coarse aggregate or a decrease in the
sand-aggregate ratio increases the CTE for concretes made with river gravel and
decreases the CTE for concretes made of granite.
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ACKNOWLEDGEMENTS
I would like to thank my advisor Dr. Anton K. Schindler for his direction
throughout my entire studies at Auburn University.
This project would not have been possible without the tireless
efforts of the many faculty, not forgetting my committee members, graduate and
undergraduate students working in the Structural Research Laboratory at Auburn
University. To you all, I say thank you.
Special thanks also goes to Mr. Billy Wilson, the structural research laboratory
technician at Auburn University, for his guidance, and help throughout my research work
at Auburn University.
I am also grateful to all my family members who helped me in diverse ways
throughout the course of my studies at Auburn University.
Finally, I would like to thank God. All things are truly possible in His name. I
thank Him for staying with me throughout all of my pitfalls and for blessing me with
such a wonderful life and the opportunity to bless His Holy name.

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Style manual or journal used: Chicago Manual of Style, 15th Edition.

Computer software used: Microsoft® Word, and Microsoft® Excel

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TABLE OF CONTENTS
LIST OF TABLES………………………………………………………………….…...xvi
LIST OF FIGURES………………………………………………………………….….xxi
CHAPTER 1: INTRODUCTION.......................................................................................1
1.1 BACKGROUND......................................................................................................1
1.2 RESEARCH NEEDS STATEMENT.......................................................................9
1.3 OBJECTIVES OF STUDY.....................................................................................10
1.4 SCOPE....................................................................................................................10
CHAPTER 2: LITERATURE REVIEW..........................................................................12
2.1 FACTORS AFFECTING THE CONCRETE COEFFICIENT OF THERMAL
EXPANSION................................................................................................................12
2.1.1 Moisture Content.............................................................................................13
2.1.1.1 Pure Thermal Dilation...............................................................................17
2.1.1.2 Thermal Shrinkage and Swelling..............................................................17
2.1.1.3 Relative Humidity Change........................................................................18
2.1.2 Aggregates.......................................................................................................23
2.1.2.1 Aggregate Mineral Composition...............................................................25
2.1.2.2 Aggregate Volume....................................................................................29
2.1.3 Age of Concrete...............................................................................................31
2.1.4 Temperature.....................................................................................................34
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2.1.4.1 Variation of Thermal Coefficient of Expansion with the Expansion and
Contraction phases................................................................................................36
2.1.5 Water-Cement Ratio........................................................................................36
2.1.6 Paste Composition/Richness of Mixture..........................................................37
2.2 MEASUREMENT OF THE CONCRETE COEFFICIENT OF THERMAL
EXPANSION................................................................................................................39
2.2.1 Standard Method of Test for Coefficient of Thermal Expansion of Hydraulic
Cement Concrete - AASHTO TP 60 (2004).............................................................39
2.2.1.1 Testing Procedure.....................................................................................40
2.2.2 AASHTO TP 60 using the Regression Analysis Method................................43
2.2.3 Vibrating Wire Extensometer Method.............................................................47
2.2.4 Environmental Extensometer Method.............................................................50
2.2.5 Loubser and Bryden Apparatus.......................................................................51
2.2.6 Ziegeldorf, Kleiser and Hilsdorf Method.........................................................54
2.3 MODELS FOR CALCULATING THE CONCRETE COEFFICIENT OF
THERMAL EXPANSION............................................................................................56
2.3.1 Emanuel and Hulsey’s Model..........................................................................56
2.3.2 CHEM 2 Model................................................................................................58
2.3.3 Neville and Brooks Model...............................................................................60
CHAPTER 3: SUMMARY OF THE GEOLOGY OF ALABAMA RELEVANT TO
CONCRETE AGGREGATE............................................................................................64
3.1 IMPORTANCE OF THE KNOWLEDGE OF GEOLOGY...................................64
3.2 GENERAL GEOLOGY OF ALABAMA..............................................................65
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