Determining the water content of concrete panels by using a microwave moisture meter

Abstract

Synopsis Sections of 1 × 2 m, sawn from full-size commercial concrete panels, were tested with a microwave moisture meter to establish calibration curves for different types of concrete cladding panel. The tests confirmed that the relationship between microwave attenuation and percentage of absorhed water for such panels was linear, but it was also found that the slope of the curve depended upon the particular construction of the concrete panel. With 10% absorbed water, the microwave attenuation varied between approximately 10 and 20 dB. Anomalous results were obtained during freezing weather and these were attributed to molecular orientation of the water in the concrete.