Electromagnetic properties of Portland cement concrete using microwave nondestructive testing techniques / Hashem Mohd Ali Al-Mattarneh
The use of electromagnetic waves as a nondestructive evaluation technique to evaluate Portland cement concrete (PCC) structures is based on the principle that the change in structure, composition, condition, or basic properties of PCC results in a change in its electromagnetic properties. The nea...
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| Format: | Thesis |
| Language: | English |
| Published: |
2000
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| Subjects: | |
| Online Access: | http://ir.uitm.edu.my/id/eprint/4236/ http://ir.uitm.edu.my/id/eprint/4236/1/TM_HASHEM%20MOHD%20ALI%20AL-MATTARNEH%20EC%2000_5%201.pdf |
| Summary: | The use of electromagnetic waves as a nondestructive evaluation technique to
evaluate Portland cement concrete (PCC) structures is based on the principle that the
change in structure, composition, condition, or basic properties of PCC results in a
change in its electromagnetic properties. The near field open-ended rectangular
waveguide is one of the few devices that can make accurate measurements of the
electromagnetic properties ofPCC in the frequency range of7.0 GHz to 13.0 GHz. A
microwave measurement system using open-ended rectangular waveguide developed
at Universiti Teknologi MARA was used to measure the electromagnetic properties
of PCC. Also, a study was conducted to investigate the effect of the basic properties
and conditions of PCC, namely, curing time, water cement ratio (w/c), moisture
content, curing type, compressive strength, cement type, cement content, aggregate
type, aggregate ratio and maximum aggregate size on the electromagnetic properties
ofPCC.
Measurements were conducted in the frequency domain. The research found that, the
electromagnetic properties decrease with increasing curing age. The electromagnetic
properties of PCC with lower w/c ratio is lower than the PCC with higher w/c ratio at
early age of curing, this is reversed after hydration (curing) is completed. The
electromagnetic properties of PCC increase with increasing moisture content. There
is a significant difference in the electromagnetic properties of PCC cured using
different type of curing methods such as, submerged in water, cover by wet cotton
and cured in air and ambient humidity. The microwave nondestructive testing using
near field open-ended rectangular waveguide can be used for determination of w/c
ratio, compressive strength and moisture content from the measurement of reflection
coefficients, dielectric constants, loss factors and conductivity. There is no
significant difference between the electromagnetic properties of PCC mixes using
different type of Portland cement (Type I and Type II). Mixes containing limestone
aggregate had a lower reflection coefficient than those containing granite. Also,
mixes containing limestone had a greater dielectric constant and loss factor than
those containing granite. |
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