The use of cores is an integral part of the assessment of existing structures that are modernized. redesigned or have been damaged. Evaluation of the test results and the estimation of characteristic values of compressive strength can be performed according to the statistical method proposed by the Annex D of the PN-EN 1990 [1] standard. and also according to the PN-EN 13791 [2]. https://www.hindigyanvishv.com/