1/2” vs 3/4” aggregate?

[PUGLIA]

We have to pump the concrete up for my slab. The pump cannot use 3/4” aggregate. I’m stupid on all things concrete so I thought I would post on here to get opinions.

Everything that I have read is saying that 1/2” is “stronger” though not by much. Is that correct? Is there anything I need to be concerned with or ask my concrete guy? I’m building a 40x40 bolt up red iron shop on this thing so I want to make sure the slab is right.


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[ConCretin]

The batch plant will adjust the cement for the aggregate size to provide the same compressive strength. I don't see why the pump can't use 3/4 aggregate - it's the standard concrete mix - but if so, the 3/8 will be fine but expect more shrinkage than with larger aggregate. Make sure you cut your control joints in a timely manner and keep the spacing in the 8 to 12' range.

 

[readhead]

I’m guessing you are using a line pump. As LL mentioned the batch plant will take that into account.

 

[joes169]

I'm with LL, pretty rare to hear that someone can't pump 3/4" aggregate. I'm guessing they simply don't want to. I'd recommend looking for another pumper, or better yet, looking into a conveyor truck, to aid you in placing the concrete.

I know a lot of folks drool over the thought of pumping concrete (at least on the internet, it seems) versus the alternatives, but it definitely has it's downsides. A lazy/ignorant/under-educated pump operator can ruin an entire concrete pour.

One of my ready-mix concrete salesman summed it up recently very well, IMO. He said something like "concrete pumpers probably destroy more good concrete than Mother Nature", and I tend to agree with him.......