Sand and macadam for self-mixing

[nimhed]

I was thinking of having a sand pile and a gravel pile so I can easily mix some concrete, mortar, or render mix.
The question is which dimension I should buy. It would be nice if the sand works for all the mixtures.

In the near future, I'm going to cast some posts for a fence, cast a small slab for LVP. Build up walls with lecainne blocks. Finish plastering some interior walls.

So,
Sand:
0-4 or 0-8?
Gravel:
8-16 or even coarser?

As I said, it would be nice to just have two piles.

 

[nimhed]

Bricklayers don't hang out on byggahus, do they?

 

[hul]

I was thinking of having a sand pile and a macadam pile so I can easily mix some concrete, mortar, or plaster. The question is what dimension I should buy. It would be nice if the sand works for all the mixes.

In the near future, I'm planning to cast some pillars for a fence, pour a small slab for LVP, and build lecainne walls. Finish plaster a few interior walls.

So,
Sand:
0-4 or 0-8?
Macadam:
8-16 or even coarser?

As I said, it would be nice to just have two piles.

As much stone and as large as possible, they are crucial in concrete.

 

[nimhed]

So 8-16 is on the small side?

 

[Oldboy]

To what you've indicated, mainly sand works, right?

In pre-mixed mortar and concrete bags, I seem to remember it says the maximum grain size is 3 mm?

 

[hul]

So 8-16 is on the small side?

hello

no, 8-16 sounds good but need much more info to answer exactly.

depending on how you reinforce, it determines the dmax, the largest stone size. The stone must be able to move freely past all reinforcement.

then you want the largest dmax possible to reduce shrinkage cracks and increase the strength of the concrete.

 

[justusandersson]

My concrete knowledge goes back in time, so I must allow for some memory lapses.

I don't think you can manage with just two piles, at least not with any quality in the final result. For concrete, you need both sand and gravel. For plaster mortar, you need fine-grained sand. The strength of the concrete increases when using as little water as possible in relation to the cement. In practice, this means a lot of coarse gravel, preferably up to 64 mm. The proportions between the different fractions are also important. I would say you need at least four piles. Plaster sand, 0-4 for mortar and concrete, 4-16 and 16-64 for concrete. The borders are not sacred. Much depends on what you intend to use it for.

 

[hul]

My concrete knowledge dates back, so I must make a certain reservation for memory lapses.

I don't think you can manage with two piles, at least not with any quality in the end result. For concrete, you need both sand and crushed stone. For plaster mortar, you need fine-grained sand. The strength of the concrete increases when you use as little water as possible in relation to the cement. In practice, this means a lot of coarse gravel, preferably up to 64 mm. The proportions between the different fractions are also important. I would say you need four piles at least. Plaster sand, 0-4 for mortar and concrete, 4-16 and 16-64 for concrete. The boundaries are not sacred. Much depends on what you are going to use it for.

nah, it feels like overkill with 64mm, you almost never use over 27mm.
It's hard to even reinforce.

 

[justusandersson]

As I wrote, my knowledge is a bit outdated. But for the highest strength requirements, such as in foundations, very coarse aggregate is required. But of course, anything over 16 is difficult to handle manually. My intention was mainly to formulate a principle; for high strength, very coarse material is needed. Additionally, the more piles, the easier it is to balance the different fractions.

 

[nimhed]

I would say you need at least four piles. Plaster sand, 0-4 for mortar and concrete, 4-16 and 16-64 for concrete. The boundaries are not sacred. Much depends on what you are going to use it for.

Are plaster sand and 0-4 two different things? They must be, otherwise I'm not counting four piles
So what is plaster sand then?
Yes, I did hint at what I would be using it for. Posts for fences, a small slab for the outdoor unit of the heat pump, mortar for building interior walls with leca.

We can disregard plaster mortar for now.

So, mortar for leca and concrete for posts + a slab of max 2 sqm.

Sand 0-4
Macadam 16-24

How does that sound?

The posts are not reinforced and the slab is not very big, but maybe we should throw in some 8mm reinforcement in it.

 

[nimhed]

hi

Well, 8-16 sounds good but I need much more info to answer exactly.

Depending on how you reinforce, this determines dmax, the largest stone size. The stone must be able to pass freely past all reinforcement.

Then you want the largest dmax possible to reduce shrinkage cracks and increase the strength of the concrete

dmax = max dimension?

What additional information should I include?

Grateful for all the help
I'm really more of a wood guy

 

[justusandersson]

For normal plaster mortar, 0-4 is too coarse. However, it is sufficient for masonry mortar. A rule of thumb is that the largest fraction is at most 1/3 of the joint width. If you're just casting piers for fence posts, 8-16 is enough. There are no durability requirements for that. So if you're just doing some simple masonry and casting without major requirements, I suggest a pile of 0-4 and a pile of 8-16.

 

[nimhed]

Is there any downside to increasing the size of macadam other than that it's more difficult to handle?

 

[sinuslinus]

Buy prepared mortar in a bag for much more consistent quality than if you mix it yourself.

Here's a recipe for concrete:
https://www.cementa.se/sv/betongarbeten

And here's someone who thinks like you with two piles...
https://www.tenico.se/tips/tips51.htm

 

[PNO]

I have had masonry sand, which I believe is sorted 0-3, casting gravel 0-8, and crushed stone 8-11 or 8-16 at home to handle both masonry, plastering, and casting. But I have it good, I speak nicely with the local hauler, and then I can just fetch a car trailer with what is needed at the moment.

The masonry sand and casting gravel are not interchangeable. They behave completely differently when mixing concrete. This might vary from supplier to supplier, but when I've tried mixing concrete with masonry sand, it hasn't turned out well. It's as if the larger round stones in the casting gravel are needed to make the concrete flow, without having to use an abnormal amount of water and cement. It doesn't help that regular crushed stone is very sharp. From what I've heard, concrete plants use a mix of crushed stone and natural gravel as ballast.

Probably coarser ballast is better, but even 8-16 is not fun to shovel by hand.

If I'm going to do a lot of masonry or plastering, I prefer sand in a pile over pre-mixed any day. It's so nice to avoid standing in the dust and emptying bags. For small jobs, repairs, and the like, pre-mixed is better.