Assessment procedure of determining compressive strength of hardened reinforced concrete structures

As a heterogenous material, hardened concrete has several properties which have influence to the quality, compressive strength and service life. As there are several properties to examinate, there are multiple examination methods for different properties. Scope of this research was to introduce testing methods which are related to the examination of the concrete compressive strength, and furthermore to create a procedure for conducting effective examination of the compressive strength of structural concrete. During the carrying out of this research, application of standard SFS-EN 13791 in Finland was in progress. Standard SFS-EN 13791 was published in 2019 and its scope is assessment of in-situ compressive strength in structures and precast concrete components. As concrete compressive strength is the most important property of concrete, a special attention was given to the determination of in situ compressive strength. This was done in accordance with the standard SFS-EN 13791 clause 8 and its Finnish application standard SFS 7508. By carrying out the experimental examinations, it concretely helped to create understanding of the procedure of determining properties of hardened reinforced concrete. The procedure should be done systematically, where analysing the results of first examination can lead to the next needed examination method. As a final result of this research, a flowchart was produced. The flowchart was produced in respect with standard SFS-EN 13791 clause 8 and its Finnish application standard. Scope of the flowchart was to introduce how many cores need to be extracted with possible indirect testing, in respect with the size of test region and the examination method.