Wireless Data Transmission through Concrete Structures

Chloride ion presence in the concrete pore solution is an important factor in the initiation of rebar corrosion. Therefore, elevated chloride concentration in the pore solution needs to be detected as early as possible. For this early detection to be achieved, it is ideal to deploy sensors inside the concrete structure itself. This allows real time sampling of the pore solution which is closest to the rebar. To achieve this one needs to have a system based on wireless communication which allow the sensors to communicate within the structure. This would avoid wired communications methods, which impart fragility and implementation difficulties. This literature review paper endeavours to look at the various types of radiation which can be harnessed to penetrate through the opaque concrete structure. Potential data transmission methods utilising Radio Frequency Radiation, Ultrasonic Radiation, X-Ray Radiation and Neutron Beam Radiation physics were reviewed and evaluated against a set of parameters. The paper scores each radiation type against System Size, Power Supply Requirements, Transmission Range, Complexity of Circuits and Safety issues. Through these scores, each transmission technology was graded on its potential to act as the basis on which to build a micrometre sized intra-concrete data transmission system. The paper shows that ultrasonic radiation is the most promising radiation technology for use in this application.