Predicting Compressive Strength - I-Cal Strength - Calmetrix I-Cal 8000 User Manual

Calmetrix I-Cal 8000 User Manual
I. PREDICTING COMPRESSIVE STRENGTH DEVELOPMENT – I-CAL STRENGTH (Optional Module)
I-Cal Strength is based on the assumption that for a given mix design with a given porosity there is a
correlation between the energy released (degree of hydration) and the compressive strength development.
As with traditional maturity, the assumption is only valid for mixes with the same materials and proportions.
How to use the I-Cal Strength module.
To be able to predict compressive strength development for a given mix design, you will first have to create
a model which establishes the relationship between degree of hydration and compressive strength.
IMPORTANT NOTE: Any given model is only valid for prediction of other mixes WITH THE SAME
MIX DESIGN tested at the same temperature. Hence, I-Cal Strength works well for standard mixes
or high volume mixes used often in next to similar conditions.
Experience has also demonstrated that the model works for predictions of mortar mixes with minor
deviations such as using a slightly different admixture type or dose. However, the mixing method as
well as binder, water, air and sand type and content cannot be changed without having to re-
develop the model. The use of defoamer is also recommended to minimize variable air entrainment
whenever possible. Hence
First, build a model
To build a new Model for a given mixture, proceed as follows:
1. Go to I-Cal Strength and select the "Modeling" tab. Click on New Model (a)
2. Click on "Add Modeling Log" (b). A new window will pop up, letting you browse to the file containing
the calorimetry curve for the mix for which you would like to build a model. You can load up to 8
curves for the same mix.
3. Select one or several curves for this mix. As shown in the example below, the software will plot
Energy/Cementitious Material for the curve(s) you selected.
4. For each curve, select the "Maturity Start Time" (c). The Maturity Start Time is the beginning of the
main hydration, when strength is starting to build in your mix. This should be the Initial Set Time of
the mix, if known, and in any case at least 30 minutes longer than the Time to Iso, which can be
determined in I-Cal Reports using the guidelines on page 21 of this manual.
5. Define your extrapolation. I-Cal Strength lets you extrapolate a calorimetry curve. Enter an
"Extrapolation Start Time" (d) and a "Max Extrapolation Time" (e) to determine the time window for
© 2010 - 2012 Calmetrix Inc. – All rights reserved
31