When Safe to Move Ballast Box with Fresh Concrete

[WranglerX]

Just made a 2x2x1ft. (4 cu-ft) steel ballast box for my SCUT (MF 1715)... Filled with about 8 sacks of Sacrete, estimated to weigh about 600 pounds... When is it going to be cured enough to be safely uses with out danger of messing with integrity of concrete cure...

Dale

 

[Streetcar]

If possible wait 28 days

 

[RNeumann]

It will make it’s specified compressive strength at 28 days (book answer) and continue to harden with time. The reality is it will make most of its strength in a week or so. Sidewalks etc can be walked on in a few days. Without photos or a design I’m guessing it can be moved gingerly after a few days and abused after a few weeks.

 

[Whitbread]

I only waited a week before hanging my concrete ballast box. My mounting studs didn't pull out and it didn't fall off the front of the tractor. So while not ideal circumstances, it all seemed to work out. Mine held three 80lb bags of quickrete.

 

[WranglerX]

Box is full steel cases and all mounts are welded or bolted to steel case, it fully contained the concrete as just a fill and other than wracking motion of box there should be no stress on concrete fill...

Pictures later...

Dale

 

[RickB]

Box is full steel cases and all mounts are welded or bolted to steel case, it fully contained the concrete as just a fill and other than wracking motion of box there should be no stress on concrete fill...

Pictures later...

Dale

2 days.

 

[ovrszd]

Just long enough that it doesn't slosh over the sides.

You said the box is self contained and supported. No wait time required.

 

[k0ua]

Just long enough that it doesn't slosh over the sides.

You said the box is self contained and supported. No wait time required.

I was thinking the same thing. If it don't slop out your good to go.

 

[RickB]

Just long enough that it doesn't slosh over the sides.

You said the box is self contained and supported. No wait time required.

I was thinking the same thing. If it don't slop out your good to go.

I don’t disagree, so long as he doesn’t use it for a rear mounted battering ram. I was hedging a bit so the 28 day gang didn’t crucify me.

 

[rgr33]

I waited 3 days on my 650 lb concrete box.

Would have been of been ok with using it before that if it was necessary.

 

[ovrszd]

I don’t disagree, so long as he doesn’t use it for a rear mounted battering ram. I was hedging a bit so the 28 day gang didn’t crucify me.

They can be heartless.

 

[Streetcar]

My 28 day was based on using concrete structurally and most people that use bag mix use too much water. For weight in a box you are good the next day

 

[ovrszd]

My 28 day was based on using concrete structurally and most people that use bag mix use too much water. For weight in a box you are good the next day

At a glance your answer was technically correct. Upon further inspection it becomes apparent the concrete mix is contained and simply weight.

 

[chim]

For our pours at work we have test cylinders broken at 7 and 28 days. Nearly all cylinders have compressive strength at greater than design mix for the 7 day break.

 

[oosik]

My blob of concrete stayed in the form for a bit over two weeks. Estimated weight - 480 pounds. There is a short lifting chain - center, top of the blob.

View attachment 577590

 

[fried1765]

My blob of concrete stayed in the form for a bit over two weeks. Estimated weight - 480 pounds. There is a short lifting chain - center, top of the blob.

View attachment 577590

What type of form did you use for that Oosik? Wood or steel?
Also..... what brand/model vibrator?

 

[oosik]

Fried - the form was plywood with 2x4 edges to hold it all together. Vibrator - you gotta be kidding. This was strictly a slop and drop job. As you can see - over the years the edges have suffered somewhat. But it still works.

 

[orezok]

Having built a half a billion dollars worth of public schools where we were required to probably test 10,000 cylinders, approximately 9 out of 10 reach 100% of design strength at 7 days. Twentyeight day strength usually hit 135 to 175% of design strength.

Of course, this was not Quikcrete.

 

[fried1765]

Fried - the form was plywood with 2x4 edges to hold it all together. Vibrator - you gotta be kidding. This was strictly a slop and drop job. As you can see - over the years the edges have suffered somewhat. But it still works.

I WAS kidding !!!

 

[chim]

............Also..... what brand/model vibrator?

Not sure on the particulars, but I'd guess it was delivered in a plain brown package