Correlation study of dielectric constant compared to the strength of concrete block using microwave non destructive testing (MNDT) / Kamal Shahril Kamarwahiddin

The main objective of this paper to presents a method in determining the correlation between dielectric constant and the strength of concrete block using Microwave Non Destructive Testing (MNDT) at frequency X band with range of 8 GHz to 12 GHz. In order to complete this research, 30 samples from the 3 types of concrete cube had been collected from HTC concrete company and test it using MNDT technique. In order to know the electric properties such as dielectric constant loss factor and loss tangent, MNDT technique used free-space microwave measurement (FSMM) in order to get the data by reflection and transmission measurements in free space from the samples. Different grade of concrete block give different value of dielectric constant, factor loss, and tangent loss. Concrete block has an ideal characteristic of dielectric constant which is in between 2.1 - 2.3. All the results from experimental work were observed and analysed using FOTRAN software based on Su and S21 parameters that measured by Microwave Non Destructive Testing (MNDT). From the results, obtained the average value of dielectric constant for concrete block grade 20 is 2.4, grade 30 is 2.6 and grade 35 is 3.0. Higher dielectric constant reflects higher strength of concrete block.