Limestone dust vs. sand for concrete base

[Steve IA]

I am pouring a small sidewalk area with concrete. I have a large supply of limestone (1/2" small rocks and dust) available close at hand, but would have to buy and haul sand to use as the base for the concrete. Can the limestone be used successfully instead of the sand? Given that either will be tamped well before concrete poured. Thank you. Steve southiowa

[RicodJour]

As long as the limestone has a range of sizes - from dust to pebbles - and you compact it well, that'll be fine.

BTW, most people would omit the aggregate base layer when placing a concrete sidewalk unless there was a problem with drainage or clay soil. Compacting the dirt (non-organic, not topsoil) would work as well otherwise.

R