In English | ISSUE 2/2024
Round-robin tests of concrete testing laboratories in 2023

In English | ISSUE 2/2024
Round-robin tests have been organized annually for accredited concrete testing laboratories. In 2023, compressive strength and protective pore analysis with thin and polished section were tested. Totally 15 testing units participated in the compressive strength testing and 8 testing units in the pore analyses.
In the concrete strength testing, ready-mix concrete having the strength class of C40/50 having the maximum aggregate size of 18 mm and slump class S2 was used. The average compressive strength of totally 90 test specimens was 48,6 MPa (cylinder strength) and the standard deviation was 1,26 MPa. The coefficient of variation was 2,6%. The lowest individual test result was 43,9 MPa and the highest 52,3 MPa. Two laboratories were needed to test 8 days later as required and those results slightly differed from the other results. Generally, the variation was small, and it was on the same level as in the previous years. The average density of the test specimens was 2392 kg/m3 and the standard deviation was 8,1 kg/m3. The variation was low and slightly lower compared to the previous year.
The thin and polished section analyses divided into three parts. Pair of thin sections circulated in seven laboratories (totally 9 analyses were carried out). In addition, two concrete samples were sent to the laboratories. Finally 2 thin sections and 2 polished sections were tested in two another laboratories. Generally, the variations were high. Typically the standard variation was app. 0,040 mm and the high variation was caused by some different results. Recommendations were given to reduce the variation of the test results.
Sivusto käyttää evästeitä käyttökokemuksen parantamiseksi. Keräämme myös anonyymiä tietoa sivuston käytöstä, jotta voimme tarjota sinulle kiinnostavaa sisältöä. Voit kuitenkin estää tietojen keräämisen Kävijämittaus ja analytiikka -painikkeesta.
Toiminnalliset evästeet ovat verkkosivuston toimivuuden ja kehityksen kannalta tarpeellisia. Toiminnalliset evästeet eivät tallenna tietoja, joista sinut voitaisiin välittömästi tunnistaa.
If you disable this cookie, we will not be able to save your preferences. This means that every time you visit this website you will need to enable or disable cookies again.
Please enable Strictly Necessary Cookies first so that we can save your preferences!