Sulphate resistance concrete

[longisland]

Hi all,
My contractor is proposing a high silica compound with type I cement as the screeding of an oxidation pond( no lining) instead of type V cement. My friend recommends a High alluminate compound to mix with type I cement instead. My previous experience was applying a bituminous coat on a normal portland cement concrete mix. I'm not familiar with the requirements of chemical resistance for concrete structures holding non industrial sewage. Type V cement seems to be the obvious choice. If I'm stuck with Type 1 cement, what's the best way out?

Thanks

Longisland

 

[Ron]

Type V cement is more difficult to obtain than others. Type II cement is readily available and has moderate sulphate resistance. A bituminous coating would be good, whichever cement type you use. Type II cement is commonly used for wastewater structures.

Be careful with high silica mixes. Unless carefully controlled, you might get additional shrinkage cracking. In a structure such as this, minimizing cracks is certainly a goal!

 

why didn't you think about silca fume ? it is the beter way to get your target .

 

[Jim6758]

I agree with Ron that Type II cement is preferable and a good deal cheaper than Type V. If your sewage is highly corrosive, there are a number of resin products that are used to coat the inside of sanitary sewer manholes. Some of the fiberglass manholes are very effective and only require a concrete base.

 

[kjde]

If you have type I cement, why dont you blend it with GGBS (Ground granulated blast furnace slag)at your project site.Blended cements are superior in sulphate resistance as well as resistance to chloride diffusion. Type V is slowly being replaced by blended cements of late.