Concrete/Flatwork/Concrete question...

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Question
Mr. Hutchins,
I've got a concrete and stone walkway that goes up a small hill in front of my house on around to a side entrance.  The bottom three feet or so is flat, then it starts a gradual rise up.  It's a concrete base, with various-sized rocks in it...most of then odd shapes, and I suspect these were the rocks that were collected on the property when the house was originally built.  (Very rocky area.)  My problem is, the bottom three or four feet...the flat part of the walk...has started to crumble, and the rocks are popping out.  This is a real problem, because my mother can only get into my house by going up this walkway and coming in the side door.  (The front steps are way too steep for her.)
I plan to get a few bags of Quikrete and patch the walk...will save and re-use the rocks that have come loose...but wanted to ask a question.  Is there any way to get new concrete to firmly anchor onto old?  I've heard that if you really saturate the old concrete with water...then apply the new concrete...that it'll help them both adhere to one another.  Does that sound right?
Any suggestions/advice you can offer will be greatly appreciated.
Warm regards,
David Gardner

Answer
To answer your question about saturate the old concrete and apply new concrete, I'd have to answer NO that doesn't sound right.

If I'm picturing your problem correctly, I'm envisioning rocks of 4 to 8 inches in width that are basically "set" into concrete.  If that's the case, I would remove the section that you are talking about and either save or find new rock and re-pour this section, since it is rather small in size.

I'm not sure of the age, or what the cause was for this sidewalk to start falling apart, but water is usually the culprit in concrete failing one way or another.  If may be a good idea, if re-pouring, to put a good base of gravel, perhaps 4" deep to allow water to drain from below, if that seems to be where the water was coming from.  It would also be a good idea to seal the sidewalk from the top after installation.  

You may find some useful information on my concrete sealing blog. If you could give me more details and supply photos, I'd be happy to evaluate and give additional information.

Good Luck!

Concrete/Flatwork

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John Hutchins

Expertise

Questions regarding concrete damage and how to protect concrete from damage. When repairs can be made or when it's time to replace

Experience

My area of expertise is in concrete sealing and protection, along with the associated causes of concrete damage.

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BBB

Education/Credentials
Various training classes over the past 7 years. Real life applications and inspections of 1000's of concrete projects.

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