ABSTRACT
Theincreasedincidenceofdurabilityproblemsinvolvingsteelcorrosioninreinforcedconcretestructuresistheresultofseveralchanges whichhavetakenplaceinconcretetechnologyandintheenvironmental conditionsinwhichconcreteisbeingincreasinglyused.Someofthese willbeoutlinedhere:
•Sincetheperformanceofconcreteisspecifiedintermsof28-days' strength,themoderncementsaredesignedtoachievehigherstrength levelsandobtainmostoftheirstrengthpotentialwithin28days(i.e. higherC3Scontentandhigherfineness),leadingtotheuseof concreteswithhigherw/cratioandlessreserveforpost28days' hydration.Thesetwofactorsreducetheeffectivelong-termprotection oftheconcretecover.
