Chapter 9-Volume Changes hooton2017.pdf

# Calculate the effective thickness on a unit volume

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Calculate the effective thickness on a unit volume (Vol.), perpendicular to the direction of shrinkage to be calculated, for a unit drying surface (S.A. exposed): (mm) exposed S.A. Vol. m e Volume Changes of Concrete Em for a wall Volume Changes of Concrete Em for a slab on grade Volume Changes of Concrete For circular or square column there is drying in 2-dimensions exposed S.A. 2Vol. m e (mm) Volume Changes of Concrete Em for square columns Volume Changes of Concrete Going from 2-D to 1-D

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9 Volume Changes of Concrete Em for circular columns Feb 3 Volume Changes of Concrete Volume Changes of Concrete shrinkage strain of the concrete, e cs , at a given age, t. t e b c cs k k k Where ec = ultimate shrinkage strain of the cement paste fraction kb = a factor taking into account the w/cm and cement content of the concrete ke = a factor taking into account the effective thickness of the concrete element kt = a factor depending on the effective thickness and the time of drying Volume Changes of Concrete CEB Shrinkage, e cp Volume Changes of Concrete CEB Shrinkage & Creep, Kb Volume Changes of Concrete CEB Shrinkage & Creep, Ke