# Evaluating Bad Aggregate job



## eaglerc2001 (Nov 7, 2007)

Folks,
I had my builder pour a new sidewalk, with aggregate.  The finished result after drying 7 days is that it is very splotchy, some areas are good, but the concrete is coming through in other areas.  My neighbors looks great, but is 1 week older.  

I am tryingto get the builder to pull it out, and start over again.  Can anyone assess what happen, if i am being crazy, etc.?  I need to be informed to get the builder to fix the issue.

Images are below.
Bad  pics..

1 bad pic

Neighbors pic

1 good pic


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## glennjanie (Nov 7, 2007)

Welcome EagleRC:
Exposed agregrate concrete has many variables. From what I can see in the pictures a wash-down with muratic acid (1qt acid to each gallon of water) and a sealer coat would make it look great! No two exposed agregate jobs will look exactly alike but, hey that's what it is all about, we want to look different.
Just use the muratic acid to wash any concrete slury off the top of the rocks; if you leave it on until the rocks begin coming out it will be a big mess. You can get the sealer at the big box stores. Just ask the sales person for it. Use at least 2 coats of the sealer allowing 24 hours drying between applications.
Caution: When using muratic acid protect your eyes and skin from the acid; when acids get into the human body they go directly to the bones and stay there for life!
Glenn


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## Kerrylib (Nov 8, 2007)

Glenn,

Not to quibble about your words of caution regarding handling acid (ANY ACID), but muriatic acid does not attack the body as you indicated.  That would be hydrofluoric acid (HF).  Muriatic acid is also known as hydrochloric acid (HCl).  Our stomachs produce the stuff to digest food, although typically not as strong as used industrially.

Hydrofluoric acid is nasty stuff.  Not a terribly "strong" acid, but very dangerous because it will be taken in through the skin and tissue and it is very toxic.

Here's MSDS info for the two

HF  https://fscimage.fishersci.com/msds/11171.htm 
HCl  https://fscimage.fishersci.com/msds/11155.htm

Again, Glenn, I do not want to dampen your words of caution.  Everyone needs to understand what they are handling and take appropriate measures to keep themselves and anyone around them safe.

Kerrylib


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## eaglerc2001 (Nov 8, 2007)

Thanks guys.  I will get the Muratic Acid, and Sealer.  See how it goes.

Robert


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## inspectorD (Nov 8, 2007)

Glad you cleared that up... that stuff I used in high school chemistry class..to melt the seashells was HCL...good to know it woun't stick around. 

Alway's read the directions if all else fails.


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