High Temperature Chemical Resistant Concrete 2

[Luk]

Hi There!

I'm looking for a concrete mix that can resist high temperature chemical solution (100 degree celcius and ph10 and above or ph3 and below).
I an aware that with the addition of silica fume, the performance of the normal concrete can be improve.
Any other ideas?
Thanks!

 

[Luk]

Will sulphur concrete be effective?

 

[Violeta]

Hi Luk,

Sulphur concrete is chemical reistant, but I'm afraid it won't fit your requirements because of the high temperature. Sulphur concrete melts at about 120ºC, and I think you would have some trouble already at 100ºC. At room temperature, unmodified sulphur is in orthorombic state and it changes to monoclinic state at 96ºC. Many transformations could cause micro fissures and failure.

Maybe if the contact with the chemical substance is not continued, but it is only accidentally spilled (it can even have a temperature drop), sulphur concrete could have a much better performance.

Anyway, I am only talking based on my own experience with unmodified sulphur (which is not affected by temperatures of 50 - 60ºC). You should contact some of the people that are talking in the two forums about sulfur concrete. Some of them have worked in companies that produce modified sulphur concrete and they will tell you if you can use their sulphur concrete. Dohn316 worked for many years is a US company, and Ramiro Lippi is working in a Chilean one.

Regards,

Violeta.

 

[Luk]

Thanks for the reply Violeta!

 

[ansys54]

Depending on the quantity you require, there are many bagged mixes available that fit your needs. Masterbuilders, CPD, Sternson all have bagged mixes however cost/.45cu.feet is usually around $40. Generally these are used in pulp mills as floor toppings.

 

[ansys54]

Silica fume will increase resistance to sulphate attack. It acts like type 50 cement(type 5 in the U.S.) Sulphate Resistant Cement. So it depends what chemicals you're trying to ward off.

 

[dik]

I suspect that you will require a protective coating on the concrete; additives may not be sufficient. For long term exposure, sulphur concrete will not likely suffice. The range of pH is a real problem. Concrete normally does not fare well over an extended period of time with pH below 7; depending on the acid. Resistance to alkalinity is similar, but better; it depends on the chemicals involved. I had a recent similar problem project(low pH of 4 and upper pH of 12). My project was much simpler, the containment slab had been constructed; I'll keep you posted on how it behaves <G>.

You may want to contact the PCA or in Canada the CPCA for information. They have a *.pdf document that outlines the various agents and the manner of protection (I can eMail you a copy).

 

[Violeta]

I agree with dik, additives may not be sufficient, and maybe too expensive for the benefits you would obtain. The protective layer would be the best option in my opinion. I don't know what kind of structure you are planning (pavement, tank,...); depending on that, you may choose one type of protection or another.
In any case, as you need resistance to both acids and alkalis (and temperature), ceramic materials would have a good performance. I'm thinking about ceramic tiles, used in many chemical labs. And, depending on the application, you could take into account a glass layer.

Good luck,

Violeta.

 

[Luk]

Thank you everyone for the information.

I'm trying to remediate existing slabs that are in severe condition (cracks, reinforcement exposures..etc).
We have been trying polyurea/ polyurethane as a protective layer in new slabs and existing slab.
However, with direct contact of high temp. & ph chemicals, the layer doesn't seem to be performing well. It works better on top of steel tank roof where the main threat would be rain water.

Glass layer sounds interesting... I will check on that...
As usual, the main priority of the industry is to save cost (including maintenance cost). I'm trying to look for new products that may save the company some $$$.

dik, I would really appreciate it if you can email me a copy of PCA document at : lukmandou@rocketmail.com
and keep me updated with the new containment unit.
Thanks!