**4. Discussion**

The presented results for concrete tested under different curing conditions, hardening temperature, aggregate type, concrete strength, dimensions of the sample, presence of the admixtures, and presence of reinforcement show that the proposed AE method is the general method that allows for early age damage identification, damage tracking, and location.

In each of the analyzed cases, it was possible to select damage classes. The emergence of class 1 and class 2 signals does not represent direct effects on the strength level.

Evaluation of concrete strength based on the presented AE method has a qualitative nature. Therefore, it seems expedient to look for a correlation between the intensity of destructive processes and the strength of the concrete obtained.

The data obtained can also be used in several analyses of practical significance such as:


**Author Contributions:** Conceptualization, B.G. and W.T.; Methodology, B.G. and W.T.; Software, M.B.; Validation, B.G., W.T. and M.B.; Formal Analysis, B.G.; Investigation, M.B.; Resources, B.G.; Data Curation, M.B.; Writing—Original Draft Preparation, W.T.; Writing—Review and Editing, W.T., B.G. and M.B.; Visualization, M.B.; Supervision, W.T.; Project Administration, B.G.; Funding Acquisition, B.G. and W.T. All authors have read and agreed to the published version of the manuscript.

**Funding:** This experiments were funded by Project POIG No.01.01.02-10-106/09-01

**Acknowledgments:** Research was carried out as part of the Project POIG No.01.01.02-10-106/09-01

**Conflicts of Interest:** The authors declare no conflict of interest.
