In the early 1960s small line pumps came out of the grout and plaster business. These small pumps had only 3-inch lines, which would not pass standard concrete mixes. The equipment barely got by and had no safety margins on hydraulics or mechanical parts. Therefore dependability was poor, and they were limited to smaller projects.
In the middle 1960s a stiff boom was developed followed shortly by the articulated boom, which allowed starting out on the deck and reaching all the way back to the unit without moving the vehicle. For many years, 3-section booms were common; now 4-and 5-section booms are the norm.
In the early 1970s concrete pumps from Europe included heavy-duty hydraulics, developed for hydraulic backhoes. They could withstand very high pressure and sustain long periods of pumping without overheating. This made higher production possible and represents one of the most important changes in the past 50 years. With the advent of the roll-and-fold boom, 4-and 5-inch lines allowed harsher and tougher mixes to be pumped. Now 5-inch lines are standard with booms.
As pumps continued to grow with booms that reach more than 60 meters, they lent themselves to bigger projects. Big trailer pumps deliver concrete up to 70 or 80 floors and have pumped over 1000 feet in the air. It is common for trailer pumps to deliver 60 yards per hour in front of the finishers for a 30-to 40-floor building.
Read more highlights from 50 Years of Concrete Construction Progress.