Civil Engineering Reference
In-Depth Information
literally unchanged (see Chapter 18). The first mechanical
concrete pump was developed and used in the 1930s and
the hydraulic pump was developed in the 1950s. The
advanced mobile pump with hydraulic placing boom
(Fig. 10-15) is probably the single most important innova-
tion in concrete handling equipment. It is economical to
use in placing both large and small quantities of concrete,
depending on jobsite conditions. For small to medium size
projects, a combination of truck mixer and boom pump
can be used to transport and place concrete. The screw
spreader (Fig. 10-16) has been very effective in placing and
distributing concrete for pavements. Screw spreaders can
place a uniform depth of concrete quickly and efficiently.
Fig. 10-12. The tower crane and bucket can easily handle
concrete for tall-building construction. (69969)
Fig. 10-13. The conveyor belt is an efficient, portable
method of handling concrete. A dropchute prevents
concrete from segregating as it leaves the belt; a scraper
prevents loss of mortar. Conveyor belts can be operated in
series and on extendable booms of hydraulic cranes.
(69896)
Fig. 10-15. (top) A truck-mounted pump and boom can
conveniently move concrete vertically or horizontally to the
desired location. (bottom) View of concrete discharging
from flexible hose connected to rigid pipeline leading from
the pump. Rigid pipe is used in pump booms and in pipe-
lines to move concrete over relatively long distances. Up to
8 m (25 ft) of flexible hose may be attached to the end of a
rigid line to increase placement mobility. (69968, 69966)
Fig. 10-14. A conveyor belt mounted on a truck mixer places
concrete up to about 12 meters (40 feet) without the need
for additional handling equipment. (53852)
