Pozzolanic reactivity of fly ash - New test procedure

Project Number 403

The technical committee TRM (Tests for reactivity of supplementary cementitious materials) of RILEM (International union of laboratories and experts in construction materials, systems and structures) is dealing with the hydration and microstructure of supplementary cementitious materials like fly ash and works on the evaluation of reactivity test procedures (round robin test in operation). In addition to that new test procedures are under investigation.

In a first step (content of this research project) a comparison between the well-known activity index and a new procedure using the Differential Scanning Calorimetry (DSC) is planned to prove the general suitability of the new test method.

Compared to the activity index test the advantage of this test method is to have an easy reliable test procedure with good correlation to the concrete strength development, independent of the cement used and its characteristics and properties. The test results should only be influenced by the supplementary cementitious material under investigation.

Depending on the results of this project it is planned in a second step to apply for funding by the German Federal Ministry of Economics and Technology via the AiF to test and optimize the new test procedure. Among other things the reproducibility of the new test method and the statistical data, like the coefficient of variance, will be investigated in a round robin test.

The new test procedure will make a better characterization of fly ash possible, thus supporting an enlarged application of fly ash in concrete.

The project is assigned to the VGB focal point research programme "Waste Management of Coal-fired Power Plants and Waste Incineration Plants" (ERKOM) and is supervised by the VGB Technical Group Power Plant By-products.