Placing Concrete by Pumping Methods

Description

CI defines pumped concrete as concrete that is transport-ed through hose or pipe by means of a pump. Pumping con-crete through metal pipelines by piston pumps wasintroduced in the United States in Milwaukee in 1933. Thisconcrete pump used mechanical linkages to operate thepump and usually pumped through pipelines 6 in. or larger indiameter.

Many new developments have since been made in the con-crete pumping field. These include new and improvedpumps, truck-mounted and stationary placing booms, andpipeline and hose that withstand higher pumping pressures.As a result of these innovations, concrete placement bypumps has become one of the most widely used practices of the construction industry.

Pumping may be used for most concrete construction, butis especially useful where space for construction equipment is limited. Concrete pumping frees hoists and cranes to de-liver the other materials of construction concurrently with concrete placing. Also, other crafts can work unhampered by concrete operations.A steady supply of pumpable concrete is necessary for sat-isfactory pumping.

1 A pumpable concrete, like conventional concrete, requires good quality control, i.e., uniform, proper-ly graded aggregate, materials uniformly batched and mixedthoroughly.2 Concrete pumps are available with maximumoutput capacities ranging from 15 to 250 yd3/hr.Maximum volume output and maximum pressure on theconcrete cannot be achieved simultaneously from most con-crete pumps because this combination requires too muchpower.