Recommended Procedure:

1)      Obtain the mass composition of the cement clinker from either a detailed scanning electron microscope (SEM)/X-ray image analysis⁷ or the Bogue calculation.

2)      Calculate the expected chemical shrinkage of the cement at 25 ºC using the coefficients provided in Table II (and considering the availability of sulfate for the aluminate phase reactions).

3)      If the expected average curing temperature is above 25 ºC, decrease the calculated value by 0.0005 per degree C above 25 ºC.

4)      If the expected average curing temperature is below 25 ºC, increase the calculated value by 0.0005 per degree C below 25 ºC.

5)      Measure the desorption of the LWA from a saturated state down to a relative humidity of relevance for the internal curing of concrete. Saturated salt solutions of potassium sulfate and potassium nitrate, for example, can be used to obtain equilibrium RH values of about 97 % and 92 % (at 25 ºC), respectively. If desired, a "safety factor" can be applied to account for the variability in the absorption of the LWA, if multiple measurements of the desorption are performed to account for this factor.

6)      Substitute the determined values for CS and _LWA in equation (1) above to obtain the desired mass of lightweight fine aggregate in the concrete mixture.