We are pouring 8" thick, #5@15 EW, 14' tall walls with a 4000psi 3/4" mix. The pumper can't go below 4" hose for the 3/4" aggregate size and the design engineer wants to keep the 3/4" rock for strength and shrinkage. The 4.25" stinger the pumper has will not fit down inside the wall. A very...