cast in situ concrete piles

[sremotorway]

what is minimum time required to pour adjacent cast in in situ concrete piles with center to center distance of 3.2m.we are using reverse rotary method for boring of pile bores.

 

[dik]

It likely depends on the soil type; in these environs it's not uncommon to have drilled piles @ 3x diameter drilled and concrete cast slightly later...

Dik

 

[sremotorway]

the subsurface strata is sandy from medium to dense.

 

[civilperson]

If the holes are excavated immediately prior to concrete placement then a minimum strength of 80% of F'c is recommended before disturbing the adjacent soil. Using high early mix designs, this can be less than 24 hours.

 

[dik]

sandy soil... any problems with sloughing of the sand? What is the reverse rotary method?

Dik