OT- Repairing concrete ramp

[David Carlisi]

Did I somehow sort of hint at that? Tactless, of me, I am sure.


Bill

No, not really. You were offering your opinion, nothing wrong with that.

I'm thinking at this point medium range company, not one with a big building and yards of equipment, or not one with a pickup and one helper, but maybe something or someone in between.

 

[Peter.]

You can't judge the skill nor the workmanship of a company by it's size. I know one man bands who consistantly turn out top-class work and have full books on reccomendations only and I know of large companies who couldn't give a stuff if it collapsed as they went out the gate. If you're going to make a choice base it on references. If you can't get that you're stuck with a visit and going on instinct.

 

[alonzo83]

Another thought you might entertain is talking with a local gc.

Job might be too small for him to handle. But he knows who does good work and whose work will fall to shit in five years time.

 

[WILLEO6709]

I know you are getting alot of free advice..... mine for instance is not worth what you pay for it... but my experience is that the concrete place up the road has "the regular stuff" they provide if you don't ask, 5000 psi mix, 6000 psi mix, and "highway 24 hour cure" grades. I always liked the 5000 psi mix, its only a few $$ more per yard and the same labor to put it in. The 5000 psi is in tensile, compression is much higher. The biggest thing for your ramp is the subsoil prep. You absolutely don't want a crew that has the fat guy walk around on it for 29 seconds and calls it compacted....you want some kind of vibratory compactor to be used, and whoever does it have a watchdog be sure they use it for more than setting their coffee on.

 

[rbent]

A 5000psi concrete mix is compression strength, whoever told you that was tensile strength is full of it.

 

[David Carlisi]

I know you are getting alot of free advice..... mine for instance is not worth what you pay for it... but my experience is that the concrete place up the road has "the regular stuff" they provide if you don't ask, 5000 psi mix, 6000 psi mix, and "highway 24 hour cure" grades. I always liked the 5000 psi mix, its only a few $$ more per yard and the same labor to put it in. The 5000 psi is in tensile, compression is much higher. The biggest thing for your ramp is the subsoil prep. You absolutely don't want a crew that has the fat guy walk around on it for 29 seconds and calls it compacted....you want some kind of vibratory compactor to be used, and whoever does it have a watchdog be sure they use it for more than setting their coffee on.

When I worked with concrete very briefly in the late 1970's, the device was called a whacker packer, but I believe that was a nickname. It looks like a jack hammer, but has a tamping foot.
You are right about the free advice, I would have never imagined in a million years that this many guys would have this much input. I think it's great, and I really appreciate all of the help. Likewise, I try to help out here when I can. If something falls within my area of knowledge, I am always more than happy to offer advice or make recommendations.
When you ask a question like this, you realize that there are guys in other parts of the country (or world) that are having a very similar problem and want some answers as well, or others that have had concrete repairs made who learned a few things along the way and have advise. There are also those that want knowledge for the future just in case, knowing that some day they will PROBABLY run into this. In fact, this board has so many members and covers such a wide spectrum of manufacturing and other topics, that there's BOUND to be a few that are super experts on the subject, and several others that have relevant knowledge and experience and are willing to help out.

One thing for sure, I will be using 5000# concrete, that much I have learned. I started calling around yesterday. I have a friend that runs a grading company, he said that he knows a concrete guy and will send his info today. Another friend of mine owns a construction company, I have a message in for him.
When we do repair the thing, I will be sure to document with pictures.

 

[sicero]

We are talking about a little 4' X 8' patch here not a bridge over the Mississippi.
No need to make a federal case out of it.
Kenny

 

[MikeS-54]

This may have been mentioned earlier.
Make a trip to the local concrete batching/mixing plant. Go to the main office and tell them your needs/wants and let them recommend a contractor. Nice part of doing this will be that you will get someone who has been paying his bill in a timely manner. This goes a long way toward trusting the contractor in my book.

 

[true temper]

We have several good concrete contractors here in our small town. My line is if you can't finish high school you can finish concrete.

I am pretty sure rbent knows what he is talking about.

 

[David Carlisi]

We have several good concrete contractors here in our small town. My line is if you can't finish high school you can finish concrete.

I am pretty sure rbent knows what he is talking about.

What are my limits as far as temperature? Anything above freezing is ok to pour? I seem to remember 50 degrees Fahrenheit being the low limit for some reason.

 

[doug8cat]

Earlier in thread the question of putting a bonding agent on the "good" concrete at the periphery of the hole. What do those agents do (I know they cause they cause a better marriage between new and old.) but on molecular level what is going on, are they worth the time and $?

I also did not see mention of weights of vehicles that are and will use the ramp. Pretty important I would think when engineering a fix.

 

[David Carlisi]

Earlier in thread the question of putting a bonding agent on the "good" concrete at the periphery of the hole. What do those agents do (I know they cause they cause a better marriage between new and old.) but on molecular level what is going on, are they worth the time and $?

I also did not see mention of weights of vehicles that are and will use the ramp. Pretty important I would think when engineering a fix.

Our group of companies owns four forklifts, the biggest is 12,000 lb. capacity. Part of the building is sub-leased to a used forklift company, and they have everything from beer trucks to school busses.
I really don't know the answer to your question about bonding agents.

 

[Long Tom]

In my fairly amateur opinion, having personally done a few foundations and a shop slab, substrate and rebar are the primary considerations here, I mean after buying the right mix, which isn't hard.

Contrary to intuition, perhaps, is that you can use uncompacted ROUND gravel if it is contained. That's exactly what I used under my shop slab, because there was already a perimeter foundation in place to contain it. Nary a crack 3 years in, except at the expansion joins. Can be much easier.

In your situation, I'd hire a concrete cutter to remove the bad stuff and remove a little extra soil. Then I'd spend a couple hours drilling dowels into the edges of the old and epoxying rebar into them. Then I'd put in some 1/4 minus gravel- with a shovel, from my pickup- and compact it.

Then buy some dobbies and rebar (both cheap) and lay a grid with the rebar spaced a couple inches up above the gravel. Do the math to figure how many yards you need- it won't be many. Since you aren't needing cosmetic perfection you could consider finishing the slab yourself, or, just hire a guy. It's only gonna take a few hours for him. Small easy job.

I'm seeing $1500 and some elbow grease here.

 

[David Carlisi]

http://images2.snapfish.com/2323232...79=ot>3<74=;8<=:25=XROQDF>287<:<9:2<259ot1lsi

I found a contractor that repaired it properly. He sawed out the bad spot, drilled holes in the existing pad, used plenty of steel and 5000 lb. concrete.
Thanks again for all of the good advice.