The feasibility of using EM waves in determining the moisture content and factors effecting measurements in building fabrics

This work addresses the use of an electromagnetic wave sensor to determine moisture content within building fabrics. Building materials that require a special mixing ratio such as concrete, mortar and membrane layers will be subject to significant effects when exposed to unpredictable weather changes owing to the excess of the acceptable moisture content. The acceptable moisture content level varies with various building fabrics and exceeding this level will affect the overall performance of building constructions. The project proposes using a novel electromagnetic (EM) sensor to monitor, in a non-destructive manner, the signal reflected from building structures in real time to determine exceeded moisture content level. This project involves the design and construction of an EM sensor operating at two frequency ranges: 2GHz to 6GHz and 6GHz to 12GHz at a power of 0dBm. This research is a new approach for monitoring moisture in buildings which has not been investigated before. The simulation software High Frequency Structure Simulator (HFSS) was used to model the microwave sensor. The pyramidal horn antenna was chosen as the preferred antenna for this work owing to higher gain, directivity and overall performance. Different building materials and structures have been made in a laboratory environment to determine the levels of moisture content, as well as to determine the modes of building fabrics failures owing to membrane failure, a pipe burst and ground source. Finally, a graphical user interface was developed and used to control the sensor parameters as well as frequency sweep, to capture the data from the sensor. Based on the findings of this project, the EM wave sensor could be used to determine the moisture content of building fabrics in a non-destructive manner.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

Liverpool John Moores University

Year dc:date.issued

2017

Author dc:creator

• Kot, P

Contributors dc:contributor

• Shaw, A
• Jones, K
• Al-Shamma'a, A

• TH Building construction

DOI dc:identifier.doi

https://doi.org/10.24377/LJMU.t.00005338

OAI identifier oai:identifier

oai:researchonline.ljmu.ac.uk:5338