[farmerjohn1324]

This was a spot where there had been a clean-out pipe sticking up that I had to cut off and Jackhammer the concrete to cut the pipe below the level of a concrete. I filled it in today and it's not exactly level, the large rocks in the bag of concrete that I had made it difficult to level with a piece of wood.

My mixing method probably wasn't the best. I had a 5-gallon bucket and used more powder than I thought necessary, then I filled with water but it was too deep for me to see if it was all mixed. I poured enough in the hole but then had to go back and forth adding more water and more powder to get a good enough consistency.

Also, are bags of concrete waterproof? Is that a waterproof membrane included in the bag? What about grout and thinset?

 

[SeniorSitizen]

Did you learn how to work ratio and proportion math problems in about 7th grade?

 

[ClarenceBauer]

I would rent a Walk behind concrete floor grinder.
Option # 2 if the rental center will rent to a DIY'er rent a Concrete Planer / Scarifier.

 

[farmerjohn1324]

I would rent a Walk behind concrete floor grinder.
Option # 2 if the rental center will rent to a DIY'er rent a Concrete Planer / Scarifier.

That solves the problem, but doesn't clarify why it happened.

Does this type of bag I bought have more aggregate than some others? I could have easily gotten it smooth if the large rocks weren't preventing that. I see no evidence of these large rocks in the concrete they used in the shower floors (different type, black/yellow bag pictured). The type I used was in this green bag.

 

[farmerjohn1324]

I would rent a Walk behind concrete floor grinder.
Option # 2 if the rental center will rent to a DIY'er rent a Concrete Planer / Scarifier.

Also, I have one of these... Maybe it would work on a small area.

https://www.homedepot.com/p/RIDGID-...1_RI-9qNn0rXN3pxtHhoCwTIQAvD_BwE&gclsrc=aw.ds

 

[ClarenceBauer]

I don't know how big the repair was to start with but here are some reasons why it turned out as it is.
Did not have the proper tools to work concrete or tools were not available.
Improper mix was used?
Looks like a poor managed work work area.
Poor knowledge of how to work concrete.

 

[farmerjohn1324]

I don't know how big the repair was to start with but here are some reasons why it turned out as it is.
Did not have the proper tools to work concrete or tools were not available.
Improper mix was used?
Looks like a poor managed work work area.
Poor knowledge of how to work concrete.

Are there different amounts of large aggregate depending on the type of bag that I buy?

 

[ClarenceBauer]

I would think that the avg. size aggregate in the bagged mix would not exceed 3/8 to 1/2 inch just my guess. What did the package spec. data state for the product used.

 

[stadry]

suppose its possible there were some larger size aggregate in the mix but it had to be thrown in by a disgruntled worker,,, most likely your created hole was too shallow for the mix,,, walk-behind grinder or scarifier's o'kill impo,,, even tho we own them, we'd use 4 or 7" grinder & grind down the high spots then fill w/rapid set cement,,, don't forget to rent a vac too & change/shake out the filter OFTEN ! ! !

 

[farmerjohn1324]

suppose its possible there were some larger size aggregate in the mix but it had to be thrown in by a disgruntled worker,,, most likely your created hole was too shallow for the mix,,, walk-behind grinder or scarifier's o'kill impo,,, even tho we own them, we'd use 4 or 7" grinder & grind down the high spots then fill w/rapid set cement,,, don't forget to rent a vac too & change/shake out the filter OFTEN ! ! !

The bag I used said "Very Rapid Hardening Concrete."

Do you use actual CEMENT mix? Not concrete?

 

[Msradell]

The bag I used said "Very Rapid Hardening Concrete."

Do you use actual CEMENT mix? Not concrete?

Cement is only one ingredient in concrete, cement alone cannot be used. You mix a cement with an aggregate of some type, normally sand and aggregate. Many times, other chemicals are added for specific purposes.

 

[farmerjohn1324]

The bag I used said "Very Rapid Hardening Concrete."

Do you use actual CEMENT mix? Not concrete?

Cement is only one ingredient in concrete, cement alone cannot be used. You mix a cement with an aggregate of some type, normally sand and aggregate. Many times, other chemicals are added for specific purposes.

I understand that. Which is why I was wondering why he used the word cement. Is this a type of concrete with less aggregate than this? Or is this amount of aggregate normal?

 

[Msradell]

I have no idea how much aggregate was in the mix you used. But obviously some of it (or maybe most of it) was too large for what you are doing. You need one with just sand or very small aggregate.

 

[HotRodx10]

If you want to know what went wrong, your first mistake is using "very rapid hardening concrete". You get virtually no time to work with it. I'm also guessing that the hole you were filling wasn't deep enough for standard concrete mix. If any part of what you're filling is less than 2", you should be using the sand topping mix. I'm not sure what happened when you went to the store, but if you asked an employee what you should get, and that's what they recommended, I'd never step foot in that store again. If you didn't ask anyone, well...

 

[HandyAndyInNC]

I would have cut a square or rectangle and then filled that in. It looks as if you didn't trowel the concrete properly. It looks like all the gravel is still at the top. You mixed it in a bucket? Not a good idea. Using a wood board is not the correct tool. I think the easiest way is to cut it out and pour it again. This time mix the concrete properly and use a wheelbarrow or a trough. I never purchase from a box store. They carry low quality products. Did you ensure there is a good base? If not, dig down and create a proper base of compacted gravel. If mixing from a bag, ensure that you use the correct type with the correct mix. You can always mix your own recipe for what you need. Usually one will ask for suggestions before doing any work, especially something that cannot be easily modified.

 

[miamicuse]

I think your problem was (1 ) Using Rapid Set products that sets REALLY FAST which allows no time to work the product with a trowel to achieve the finish you desired (2) You said yourself you dumped the entire package into a 5 gallon bucket and did not mix thoroughly and when you dumped it into the hole you found dry mix at the bottom of the bucket and you had to add water...I think the large rock you found was already partially set chunks of mix you didn't mix thoroughly and didn't work fast enough.


I would have broken used regular concrete mix and broke it into two halves to mix in the 5 gallon bucket to mix with an electric mud mixer.

 

[HotRodx10]

As far as correcting it, I agree with HandyAndy; the least amount of work and expense is to cut at least 1/2" deep all the way around with a concrete saw, chip it all out to at least 1" deep everywhere, and get a couple of bags of sand topping mix concrete. Mix it in a tub or a wheelbarrow, with just enough water that when it's well mixed it's the consistency of cottage cheese (sorry, that's the best analogy I could think of at the moment). You can screed it (scrape it off level) with a board, but you'll need to smooth the surface with a concrete trowel.


That advice is assuming that you don't have anyone that has worked with concrete before that you can ask or bribe to help you for an hour. There's an art to finishing concrete that takes practice to get right. Even on a small project, it's very much better to get help from someone with experience, so you can practice with some guidance as you get a feel for how it's done.

 

[stadry]

HotRodx10, well-said BUT buyers generally have more knowledge than the store employees,,, i'd like a nickle for ea time i've o'heard a clerk recommend an incorrect method/mtls to a diy'er
your suggested method is a dot spec as i recall for spall reprs - @ least in ct, ga, pa, nj, ny, & fed $ projects

 

[HotRodx10]

HotRodx10, well-said BUT buyers generally have more knowledge than the store employees

Well, I do, and you probably do. Obviously, it depends on the store and how management trains their flunkies. Good store management teaches employees not to give advice on subjects they are not knowledgeable about. That said, recommending rapid set concrete to a customer who obviously doesn't know much about concrete work is egregiously irresponsible, and would indicate a complete lack of proper training by the management. I stand by my statement - in that situation, that store would be scratched from my list of places to shop.

 

[HotRodx10]

your suggested method is a dot spec as i recall for spall reprs

That is what we spec for concrete repairs on bridges, but it is also necessary for even a passable finished product for any job, even a DIY patching job. If the OP wants it to look like crap when he's done, he already has that. I assumed if he's unsatisfied with what he has, he would want to redo it right.


Btw, our dot specs require a much stronger and more expensive concrete repair material, such as HD50.