Concrete slab-Pool storage with Muratic acid 1

[WWTEng]

According to the pool contractor the acid will be stored securely and there should be no chance of spill. But in case there is a spill, how much the concrete mix/rebar be specified. I have never done a slab exposed to acid. Any input would be great.

 

[MiketheEngineer]

Muratic acid - based on concentration can be very nasty stuff. I would keep it far away from the pool, kids, guests, etc.

 

[amec2004]

Please contact Sika for concrete coating spec.

See attached concrete coating notes from one previous project.

anchor bolt design crane beam design

http://www.civilbay.com

 

[hokie66]

Muriatic acid is the same thing as hydrochloric acid. It is a typical pool chemical, used to lower the pH of the pool water and to clean salt chlorinators. It is also used for cleaning concrete, but exposure time should be limited by thoroughly rinsing with water. It is of course hazardous, but just needs care when handling. Anyone who has a pool keeps it in the shed.

 

[TehMightyEngineer]

Wouldn't you clean off a spill before any could really get into the concrete or are you assuming that a spill sits for a while before it gets noticed?

EIT with BS in Civil/Structural engineering.

 

[MiketheEngineer]

Yes - I have used it to balance the Ph of a pool and then spilled it around to clean the deck. Does a great job!!! --- but YOU better dilute it quickly. If it gets into your sneakers - it will peel the skin off your feet!!

 

[TehMightyEngineer]

Mike: :O Are you speaking from experience?

EIT with BS in Civil/Structural engineering.

 

[Ron]

WWTeng....as hokie66 noted, Muriatic acid is a form of hydrochloric acid (actually about a 30-33% solution of HCl). It is highly reactive to concrete and will severely etch the surface and further until the reaction is consumed. Repeat this a few times and you have exposed rebar which will corrode from the exposure to the acid as well as the reduction in pH of the concrete.

Muriatic acid, sodium hypochlorite and other aggressive pool chemicals have a way of finding things to damage. I would coat the concrete and coat it well.

 

[hokie66]

Ron,
I think hydrochloric acid and muriatic acid are both solutions of HCl (hydrogen chloride) in water. The concentration can vary, as noted in the attached article, but the definition is the same.

http://en.wikipedia.org/wiki/Hydrochloric_acid

 

[Ron]

hokie66...my understanding has long been that muriatic acid is a somewhat standard solution of hydrochloric acid, sold that way so that the consumer didn't have to worry about knowing how to mix or dilute to various strengths. The typical strength ranges around 30%, but I think the standard concentration is 31.5%.

 

[hokie66]

My bottle of hydrochloric acid just says it is 32-34% HCl. When you do a water test, or when the pool shop does it, the amount of acid to add assumes a concentration in that low 30's range. When you clean a chlorinator, you then have to dilute it with water 8:1 or 10:1.

 

[dik]

Muriatic Acid and Hydrochloric Acid are the same only the former is a more dilute solution.

Both have the same effect on Concrete only the HCl will do it faster and deeper... given time, if not wiped up, muriatic acid will do the same... in addition to reacting with the basic (pH>7) material in concrete (cement), it will introduce Cl ions to accelerate corrosion.

The only means of long term protection is a suitable coating that does not react with HCl or HCl Jr. (aka muriatic acid).

We used to use muriatic acid for a flux for soldering eavestrough when I was a kid... put too much on... and it fizzes like heck (generates hydrogen) and will eventually dissolve the zinc coating.

Dik

 

[hokie66]

Ron and dik,

It seems like you both learned it the same way, but if you check any dictionary, muriatic acid is just an outdated term which means the same as hydrochloric acid. HCl is a gas, and only so much will dissolve in water, and usually this is restricted by manufacturing methods to around 35%.

 

[Ron]

Without regard to the semantics, it will screw up the concrete and rebar. Coat the concrete.

 

[dik]

Thanks Hokie... in addition to Ron's comments, Muriatic acid is a diluted solution of HCl; I don't think that either of us have stated otherwise (unless by error)... that's why I referred to it as HCL Jr.

It may be an outdated term, but it is still available under that name. Historically, the name pre-dates Hydrochloric Acid... named long before hydrogen and chlorine were even discovered...

Dik

 

[WWTEng]

WOW!!! Thanks for all the input. It appears that the best thing would be to create a 4" thick sacrificial concrete equipment pad over the SOG and then coat the pad.

 

[MiketheEngineer]

Pirate---

Yep!!

 

[dik]

Long term etched concrete is ugly... I'd go with a coating...

Dik