The feasibility of using electromagnetic waves in determining membrane failure through concrete

Concrete flat roof defects such as water leakage present a significant and common problem in large buildings, particularly in tropical countries, where rainfall is high. To monitor this condition, effective non-destructive test methods are required to detect problems at an early stage, especially hidden defects within the concrete roof, which are critical. This paper presents the potential use of electromagnetic (EM) waves for determining possible leakage of the concrete flat roof as a result of failure of the waterproof membrane layer. This study was assessed, experimentally by investigation of the propagation of EM waves through the roof and their interaction with water. Novel Microwave sensors described in the paper operate in the 6 GHz to 12 GHz frequency range using a Marconi 6200A microwave test set. A range of existing methods was reviewed and analysed. Results of experimental tests confirmed that microwaves could be used as an alternative non-destructive method for identifying water ingress caused by membrane failure into the concrete roof surface