I've been reading this group (Jeez! Isn't it busy[1]?) for a couple of weeks or so. However, I've not seen any pointers towards any sort of FAQ (or, given the wide variety of DIY activities covered herein, FAQs). I
*have* seen mention in some thread about how much aggregate and cement one might require for a given sized lump of concrete: however, I cannot now find that post.
I need to concrete in a 3in diameter pipe to my garden; this is for mounting a steerable satellite dish (of 1.2m diameter: AIUI, this can encounter a loading of about 4tonne in a severe gale[2]). I have dug a hole which "feels" right: this is 820x600mm, and although deeper, I propose filling it to 500mm (there will then be either 100mm of soil and turf on top, or shingle and a patio, depending upon the directions of the Clerk of Works ;-).
I make that approx 0.25m^3 of concrete: how do I calculate how much agg and cement is required for this?
If it's significant, I didn't encounter *any* subsoil until I'd reached the bottom of the aforementioned excavation: all the soil removed is very friable loam, almost black in colour: I'd guess that the previous occupants had put their chimney sweepings into their garden for the 180 years since the house was built.
[1] Yet, despite this, not seemingly flooded by trolls; what a refreshing change! [2] There will be approx 1.1m of this dish above ground level.