Regardless of using high quality cement and aggregates in concrete mixture, improper mixing, placement, finishing and curing practices can negatively impact the quality of concrete and cause a premature failure, or development of defects. Uneven distribution of the ingredients such as clustering of coarse aggregates, air voids or un-hydrated cement particles, significant variation in paste density, and insufficient compaction are the main results of the inadequate mixing. Microscopic analysis is the most common technique for identifying such problems due to mixing. However, this method is limited by three main issues: (i) relatively long time is required for sample preparation and performing the test, (ii) the information is obtained in 2D and just from one section, and (iii) the technique relies on the experience of the operator. To minimize these restrictions in this research, Quantitative Computer Tomography (QCT) scanning method is used as a powerful alternative to the microscopic examination to analyze the coarse aggregates and air voids in concrete samples. A computer code was developed which enables the users to perform all measurements automatically in a short period of time. Results are in very good agreement with the conventional microscopic technique. The accuracy, rapid performance and personnel independency of this method make it a promising technique for assessment, failure analysis, forensic investigations and quality control of the bridge deck concrete cores as well as laboratory samples.