How accurate is the Predictive Strength Model, and how do I read the Estimated Strength Curve?

Climate Earth's simulations, testing and customer feedback generally suggest that actual results land within about 15% of f'cr (the over design target). The Estimated Strength Curve and its shaded band show how confident the model is about the mix on screen.

• The figure above is an expectation, not a guarantee.
• Predictions apply within the range of mixes used to calibrate the model.
• Predictions don't replace trial batches, laboratory testing, or engineering review.
• It is the model's own uncertainty for the prediction.
• It is not the standard deviation of your plant's test records.
• It is not added to the requirement. Enhance designs the mix so that the expected strength, the center of the band, meets f'cr.
• Treat the prediction as less certain than one with a narrow band.
• Confirm with trial batches, laboratory testing and engineering review, which predictions never replace.
• Consider bringing the proportions closer to typical values. If they sit too far outside the model's data, Enhance may not be able to return a mix.

1. Find the requirements. Each strength requirement is marked on the curve at its age.

2. Compare the curve with each mark. The curve shows the strength the model expects at every age for the mix on screen.

3. Look at the band. The shaded band is the range of one standard deviation: the interval in which the model expects the strength to fall most of the time for this combination of materials.

4. Find the controlling age. It's the age with the smallest margin between predicted and required strength.