Concrete cure time

[iwire]

I have to replace three concrete site pole bases.

How long would you wait before installing the pole on the base.

2 -20' poles, 1 - 30' pole with two heads each.


My issue is leaving the customer in darkness vs dropping a site pole on their head.

Any input is appreciated. Poking around the web it seems like seven days but that is much longer than I was hoping.

 

[roger]

I have to replace three concrete site pole bases.

How long would you wait before installing the pole on the base.

2 -20' poles, 1 - 30' pole with two heads each.


My issue is leaving the customer in darkness vs dropping a site pole on their head.

Any input is appreciated. Poking around the web it seems like seven days but that is much longer than I was hoping.

Bob, if the 5 day forecast is calm winds I would set them in two days. If you haven't ordered the concrete yet see what the concrete plant says (their opinion) about adding an accelerator to the mix.

Roger

 

[mgookin]

The psi of the concrete mix is a 28 day design strength. That means it is expected to be at that strength within 28 days from the day you pour.

FYI when I was a grunt civil engineer in training we did concrete sampling on big job sites and we cracked cylinders in 3, 7, 14 and 28 day increments. I never saw one not get to design strength in 14 days.

If you need 2,000 psi to hold the pole and you want to set that pole in 3 days, I suggest going with a 3,000 psi mix. Make sure they don't add too much water. You can even add some accelerator to the mix to speed the curing like is commonly done in cold weather.

As to light pole bases, I have not poured or sampled them so I can't give you any specifics. If you're using someone's design, I suggest you call the person who did the design. If not, call a local engineer. I don't know what regional factors are in play (weather, seismic, wind, etc.) where you are.

 

[USMC1302]

Does anyone have experience with pre-cast light pole bases?

 

[iwire]

Does anyone have experience with pre-cast light pole bases?

Yes, but not an option for me here.

 

[Ponchik]

Rent a portable site light and install the pole light when the concrete is ready for it.

 

[iwire]

Rent a portable site light and install the pole light when the concrete is ready for it.

Noise ordinances and neighbors too close for that besides not being included in the bid.

 

[iwire]

Bob, if the 5 day forecast is calm winds I would set them in two days. If you haven't ordered the concrete yet see what the concrete plant says (their opinion) about adding an accelerator to the mix.

Roger

That sounds more in line with what I was thinking.

 

[iwire]

As to light pole bases, I have not poured or sampled them so I can't give you any specifics. If you're using someone's design, I suggest you call the person who did the design. If not, call a local engineer. I don't know what regional factors are in play (weather, seismic, wind, etc.) where you are.

The design is easy, we do a lot of them.

But normally a long time goes by between pouring them and setting poles

 

[Smart $]

...My issue is leaving the customer in darkness vs dropping a site pole on their head.
...

Noise ordinances and neighbors too close for that besides not being included in the bid.

Darkness it is.

 

[iwire]

Darkness it is.

It may well be.

Its two poles in one lot with ten total poles and the two being worked on are apart from each other. This one won't be too dark.


OTH, at another location I have a single 30' pole and just three wall packs lighting the lot. Once I take the old 30' down its gonna be dark.

 

[iceworm]

30 foot pole with lights, standard mix, two days - color me nervous. Even with a 5 day forcast of calm winds. That's a lot of weight way up there, waving around, even in a light breeze.

However:
High Early if available (isn't up here)
Or
5-1/2 sack (4000 lb) mix with all the accelerator it can take, 2" slump (or stiffer), probe vibarator - get the air out. Calm Forcast. Then maybe two full days - set the pole on the third day.

Been a couple of decades since I was doing this, but this was the method then - probably better accelerators and non-chloride as well, available now.

ice

 

[GoldDigger]

Don't forget to factor in the earth and air temperature, unless you provide heat.

 

[Fulthrotl]

I have to replace three concrete site pole bases.

How long would you wait before installing the pole on the base.

2 -20' poles, 1 - 30' pole with two heads each.


My issue is leaving the customer in darkness vs dropping a site pole on their head.

Any input is appreciated. Poking around the web it seems like seven days but that is much longer than I was hoping.

call up the concrete supplier, and see what they can do, but i'd
think if it wasn't all that cold, you could set in five days... that's a
seat of the pants thing. i've done them that quick, but it's the left
coast, and today it was 90, and tomorrow is 86..... i was doweling
a concrete housekeeping slab i poured yesterday, and it was amazing
how it was after 18 hours.... it was 2,500 psi concrete, however, and
pretty stiff when it came out of the truck.

i'm pouring concrete tomorrow, and setting switchgear friday morning,
but then again, it's not 30' high.

 

[qcroanoke]

I have to replace three concrete site pole bases.

How long would you wait before installing the pole on the base.

2 -20' poles, 1 - 30' pole with two heads each.


My issue is leaving the customer in darkness vs dropping a site pole on their head.

Any input is appreciated. Poking around the web it seems like seven days but that is much longer than I was hoping.

Seven day breaks are what we usually do. And another at twenty eight days. (We build concrete shelters)
Are you going to or be required to take cylinders and do a break test?
I am not a big fan of all the CYA advice that goes on in here but you may want to consider having a third party inspection agency test and take samples for break tests. You may need that info later if one of them did crash.....

 

[ActionDave]

Bob, if the 5 day forecast is calm winds I would set them in two days. If you haven't ordered the concrete yet see what the concrete plant says (their opinion) about adding an accelerator to the mix.

Roger

That sounds more in line with what I was thinking.

I'm not going to argue with either of you guys since I've never set pole lights. I do have some experience with concrete; it was my first job in the trades.

I would be nervous about setting a 30' pole after the concrete has only two days to cure. Maybe some temp guy wires would get you over the curing curve hump and still get the lights on right away.

Talking to the batch plant would be a good thing. There are gobs of admixes and super enhancers that are more available than when I left the trade. If they are not applicable or not cost effective I would go with the driest mix I could. More water makes concrete easier to work with but extends the curing time.

 

[kwired]

Build a temp structure of some sort to support some temp lighting if you absolutely must have the lighting. Even if that means hanging a temp light from your boom truck. If customer don't like those options explain how much more expensive other options are going to be, if willing to pay then go with those options.

 

[mgookin]

How about using direct burial poles?
Cure time = time required to backfill.

 

[qcroanoke]

How about using direct burial poles?
Cure time = time required to backfill.

He has to replace 3 poles out of ever how many are in the parking lot. I would say that they are not available as direct burial.
Bob would have checked into that I would think.

 

[wwhitney]

Your batch plant should be able to provide a product that gives you the strength you need at 3 days. For example if you usually use 2000psi concrete, a 4000 psi mix with high early strength cement should exceed 2000 psi at 3 days, as long as nobody adds extra water for workability. So you may want to add a mid-range water reducer to improve workability without extra water.

Cheers, Wayne