modulus of concrete-filled steel piles

[Dameon]

does anyone know of a good way of estimating Ecomposite for a steel pipe pile w/no internal rebar? logic says it should be greater than 29,000 ksi, but Ecomp calculation of ( A(steel pipe) * E(steel pipe) + A (concrete) * E (concrete) )/ A total, yields way to low of values.

any opinions?

 

[Panars]

Your equation is correct. The modulus will be between the modulus for steel and the modulus for concrete. Since the modulus of steel is higher, the composite modulus will be less than steel.