We've got it good in the Northwest, we don't have to bother with that fractured rock garbage. There is actually an "Aggregate Correction Factor" for other parts of the country, and its based on our rock as the standard.
Unless you've got a mess of steel in there, 3/4" rock will be fine.
graded stone costs more,,, crushed stone is the norm,,, 'flow' will largely depend on the skill of the man on the vibrator, wtr/cement ratio, & the height of the 'drop' into the forms,,, we would NEVER use graded round aggregate NOR have i ever seen it spec'd on any state dot OR fed work,,, since its probably your home, do as you wish,,, personally i would be leery of 2nd guessing trade craftsmen/experts/local conc plant's designs
You definitely want to use aggregate, pea gravel is only used for decorative uses. The sharp corners on aggregate actually make the concrete stronger than the long run compared to pea gravel. As long as the slump is correct and a vibrator is used having the concrete flow and fill the voids should not be an issue.
Much depends on where you are and the available aggregates.
In some areas with very strong and sound rounded aggregate concrete will pour and pump much easier and give any strength specified. In the same area, crushed aggregate may be too costly and tough to pour/place and work with and more expensive because of availability.
An example is an area with very good, old glacial deposits that happen to be rounded and crushed aggragtes are much more costly - limestone is not that strong and crushed glacial aggregate is harsh and costly. Go a few hundred miles east and sand is more expensive because it often has to be manufactured/crushed, that eats cement alive because of the surface area.shape of the aggregate is very important when it comes to cost because trucking is the major cost item in the price of concrete.
Some aggregate suppliers that are in both aggregate and concrete (100 trucks or more) say that concrete is the most expensive way to sell aggregate that is available. - You work with what is available locally.
Dick
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