1. Presentation by: Lillian Lau
Graduate mentor: Jamie V. Clark
Faculty advisor: David Lange
PURE MIDTERM REPORT
X-RAY COMPUTED TOMOGRAPHY FOR THE CHARACTERIZATON OF THE CELLULAR STRUCTURE OF FOAM CEMENT

2. PROJECT OVERVIEW & BACKGROUND
Current cement microstructural characterization techniques (TEM, MIP, SEM) often give incomplete information and extensive sample prep.
X-Ray CT is a non-invasive, non-destructive imaging technique with minimal sample prep.
Data is collected from the X-Ray scan and analyzed using modelling software in AMIRA.
Grayscale values are used to determine the percentage density of pores and cement in foam cement.

3. TECHNIQUE
Determine six different methods for determining thresholding values to be used in data segmentation for characterizing foamed cement microstructure via the CT data.
Convert the 16-bit images to 8-bit images with grayscale values ranging from 0 (black) to 255 (white) in AMIRA.
Apply grayscale values from the different methods to reconstruct pore and cement density.
Use the material statistics function to calculate the resultant densities for each method.
Compare accuracy of resultant densities with predicted values.
Pixel intensity histogram

4. Measured Density (g/cm3) Error between measured and CT (%)
PROGRESS
Method
Target Density (g/cm3)
Target Air Content (%)
Measured Density (g/cm3)
Results of CT analysis
Error between measured and CT (%)
Pore Volume (cm3)
Cement Volume (cm3)
Total Volume (cm3)
% Voids
CT density (g/cm3)
OTSU
0.30
83.87
0.32
1.31E-02
2.63E-03
1.57E-02
83.26
0.31
2.49
MATLAB
1.34E-02
2.38E-03
84.88
0.28
11.81
GAUSSIAN
1.03E-02
5.43E-03
65.50
0.64
100.77
VISUAL
1.25E-02
3.22E-03
79.54
0.38
19.25
0.60
67.74
1.12E-02
4.54E-03
71.14
0.54
10.39
1.09E-02
4.87E-03
69.05
0.58
3.93
1.07E-02
5.07E-03
67.82
0.59
0.086
1.08E-02
4.94E-03
68.60
2.51

5. IMAGE RESULTS Note: Images use a 500 × 500 × 500 µm volume
0.3 Density Foam Cement using OTSU
0.6 Density Foam Cement using Gaussian
Note: Images use a 500 × 500 × 500 µm volume

6. NEXT STEPS
GOALS
Analyze the material statistics for the remaining two methods:
- Backtracking
- Using a 300 × 300 × 300 µm volume
Determine the grayscale thresholding values of the two methods.
Compare the material statistics and accuracy of all six methods.
Conclude the most accurate method of foam cement characterization.
Determine the most accurate method to calculate the density of concrete and pores in foam concrete using AMIRA imaging technology.