Early tower placing booms, first introduced in the 1970s, required the use of separate cranes, massive counterweights, and nonproportional booms, and were considered for only the largest projects. But today's modern systems take less time to install and are easy to maintain and operate. They also are available as self-climbing units—equipped with their own self-contained electric-over-hydraulic tower jacking systems—that allow for quick raising and lowering of the tower section. This feature also eliminates the need for a crane in moving from one level to the next.
A CIFA KT28 placing boom with a 196-foot full-radius range recently was used on the Terrazas River Park Village project in Miami, which consists of two towers 20 and 27 stories high. The concrete delivery system, owned and operated by concrete contractor Formcrete LLC, Florida City, Fla., placed more than 40,000 cubic yards of concrete for the towers.
The KT28 is a four-section self-climbing placing boom that reaches 91 feet without needing a counterweight. The concrete pumping system, which can be either a trailer unit or a truck-mounted concrete pump, provides ready-mixed concrete to the placing boom. The boom's hydraulic system is powered by electricity, and the boom is controlled by a radio remote, allowing the operator to oversee concrete placement from a safe vantage point.
With the CIFA short pin tower hydraulic jacking system and self-directed power, the total system can be raised with minimum manpower. New technology allows for quick tower pin adjustments and, because components are mounted externally, the operator has easy access for maintaining the unit.
The hydraulic jacking system sped up the construction process on the Terrazas River Park Village project, says Formcrete's Roman Piloto Jr. In addition, the four arms of the placing boom—unlike old models that had only three arms—offered increased maneuverability and allowed the boom to be manipulated around walls, columns, and other obstacles.