I want to find out how long it takes a wall with construction moisture to dry out. Which initial moisture content should I use?
That depends on a number of individual circumstances such as the amount of production moisture (e.g. in cellular concrete or lime silica bricks), the amount of mixing water (in concrete or mortar), the amount of rain hitting the wall while it was unrendered, the season when construction took place (warm / cold) etc., so no general answer is possible here. The table gives examples for typical initial moisture contents:
Material Water content [kg/m³]
Fresh concrete:
free water 175
Concrete, 28 days old (at 70% hydratation):
bound water 85
dried water 25 ... 45
free water 65 ... 45
(sum=175)
Concrete, 3 to 6 months old (at 90% hydratation):
bound water 105
dried water 35 ... 50
free water 35 ... 20
(sum=175)
DIN 4108, "thermal protection"
practical moisture content of concrete 50
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Cellular concrete 180 ... 220
Clay brick masonry 100 ... 150
Calcium silica brick masonry 100 ... 120