This paper presents the results of an experimental investigation in wh
ich the effect of sulfates on the strength of concrete under condition
s simulating cast-in-situ and precast situations, is carried out. A ra
nge of sulfate concentrations and exposure durations are adopted and t
he strength loss in concrete due to the sulfate attack is experimental
ly determined. The results indicate that the use of precasting in plac
e of casting-in-situ is preferable, in situations exposed to sulfate e
nvironments.