Sulphate Resistant Cement 1

[dik]

Is anyone aware of an adverse reaction between concrete made with Type 50 (Type 5/V) cement when exposed to a concentrated chloride solution (automobile parking garage type of exposure)?

Anyone have a source for information on this? Does the chloride ion interfere with the cement? or hydration?

thanks, Dik

 

[civilperson]

The chloride ions will attack the steel reinforcement, not much effect on concrete until saturated solution raises the freezing point of the solution, (requiring a lower temperature for freeze-thaw deterioration).

 

[dik]

Thanks... there is no adverse reaction between Type 50 and chloride, then?

Dik

 

[sfamularo]

There is a significant issue with using type V cement and chlorides! As civilperson said, chlorides will diffuse into the concrete and cause the corrosion of the reinforcing steel.

Type V cement is a sulfate resisting Portland Cement with lower C3A (tri-calcium aluminate) than any of the other types. C3A reacts with sulfates (typically in seawater) and results in sulfate attack of the concrete matrix. So, while you would think that Type V is better, there is a downside. C3A actually helps bind chlorides and prevent them from getting to the reinforcing steel. I do a lot of marine structure design and we NEVER use Type V cement.

I recommend using Type I or Type II cement and adding a corrosion inhibitor admixture and reducing the permeability of the concrete with a supplementary cementitious material such as fly ash, silica fume and slag cement.

Regards,

Steve

 

[dik]

Thanks, Dik