When we calculate the capacity of column in pure compression, ACI allows us to use the compression force in rebars together with concrete. But at the connection between that column and the footing, ACI states that hooks can not be used to develop compression. So how the compression force in the rebars transfer to the footing ? The load will disperse from face of the rebar to the footing via bonding ? Does ACI mean that within the column, the rebars contribute to the total resistance, but at the footing, suddenly all the compression will be resisted by the concrete only ? So where the compression in the rebars goes ? It cannot be equal to Fy x As in the column and then becomes zero at the footing suddenly.