Abstract
The strength of existing concrete structures can be evaluated and quantified where necessary with non-destructive and destructive testing methods. The aim is to determine the structural adequacy of existing concrete structures and to test the integrity of the concrete structures based on their strength evaluation.
This paper investigates the procedure for the estimation of the in situ compressive strength and characteristic in situ compressive strength of concrete in structural components using direct methods (drilled core) and non-destructive testing methods using Ultra-sonic Pulse Velocity (UPV) and rebound hammers.
By carrying out the experimental investigation, it helped us to create an understanding of the procedure of determining properties of the hardened reinforced concrete. The procedure should be done systematically, where analysing the results of the first preliminary examination can lead to the next needed examination method.
As a result of this research, a flowchart was produced. The flowchart was produced in respect with standard EN 13791 [1] clause 8 and its Finnish application standard SFS 7508:2024 [2]. The scope of the flowchart was to introduce how many cores need to be extracted with possible indirect testing, considering the size of test region and the examination method.