On a Seattle foundation job in the summer of 1988, nine concrete pumps set West Coast records for placing concrete. After the first hour of pumping, with no truck-waiting time, a remarkable 1,350 cubic yards of concrete were in the hole. The boom pumps had placed a record-breaking volume that averaged 150 yards per unit. The nine pumps kept pace with the 115 ready mix trucks, enabling the continuous pour to be completed in 13.5 hours.
The foundation mat is 225x160 feet with one rounded corner. The 30,000-square-foot area required 10,700 cubic yards of concrete for an average depth of almost 10 feet. Fly ash made up 30 percent of the cementitious material used for the 7500-psi concrete that went into the mat. Using fly ash and natural sand and gravel aggregate made the concrete easier to pump by reducing line friction.