On 20 cement pastes made from cements of variable C(3)A and SO3 conten
ts and cured at different curing conditions the effect of cement compo
sition on the extent of expansion was studied. It appears that the ext
ent of the generated expansion depends especially on the C(3)A and SO3
contents in cement, but not on the SO3/C(3)A ratio. The extent of exp
ansion increases with the amount of water supplied to the cement paste
from outside.