During the first month, the concrete cylinders gained mass due to water absorption,
especially for the non-coated high w/c cylinders having higher porosity. At
later age, concrete cylinders started to lose mass. The highest mass change occurred
for the non-coated non-cured concrete cylinders made with w/c = 0.60, followed by
the cured cylinders with the same w/c ratio. None of the cylinders made with
w/c = 0.60 and coated with epoxy or silane experienced mass change