Strength contribution of admixtures in conjunction with CEM II and CEM III cements

(Figure: Blömeke/Bottke)

Tab. 1

Fresh mortar density using 225 ml of water

(Figure: Blömeke/Bottke)

Figure: Blömeke/Bottke

Mortar prisms with fly ash

Figure: Blömeke/Bottke

Strength development using 225 ml of water

Figure: Blömeke/Bottke

Tab. 2

Fresh mortar density using 191 ml of water

Figure: Blömeke/Bottke

Concrete admixtures can influence the concrete strengths substantially. A method is called for in order to determine the strength contribution of CEM II and CEM III cements and to compare it with the k-value. This paper brings two suggestions up for discussion on the examples of calcium carbonate powder and hard coal fly ash.

Concrete admixtures can influence the concrete strengths substantially. In order to calculate a reliable prognosis of the strength for making the test cubes [1] it is important to know the strength contribution of the admixture in conjunction with the cement used. There is a lack of basic data in conjunction with CEM II and CEM III cements in order to estimate the strength contribution of the admixtures. The technical data sheets of admixtures based on calcium carbonate do not give any information, and that of fly ash suppliers only to a limited extent, namely by the activity index. Regarding...