Pumping Concrete Essay Example | Topics and Well Written Essays - 2000 words

Pumping Concrete - Essay Example [3] Conventional methods of placing concrete posed many problems to the engineers of the buildings. For this purpose the 'concrete pump' was invented to pump concrete from far away distances through tubes. Pumping concrete is more economical rather than transporting concrete from a mixing plant to formwork. A continuous feed of concrete can be placed at high speed with access to every part of the site and with no need of transportation. Concrete pumping is sometimes the only possible placing method where the job is inaccessible or the timescale of the construction work makes slower methods impractical. These days pumping is gaining popularity and the only thing that's holding it back is the number of accidents that have taken place while using concrete pumps. [5] When starting the pumping operation, the pumpers are met with a common problem. The pumping pipes are dry and are usually covered with a thin layer of cement from previous pumpings. While passing through the dry pipes the concrete will gradually dehydrate, creating a plug before reaching the end of the pipe. To solve this, the pump and pipeline must be grouted with about 500 liters of a cement slurry or rich mortar. And thereon pumping should be started immediately after grouting. This can be described in the following steps: [5] 1. Pour slurry or mortar into hopper while operating the pump slowly; 2. Discharge excess grout to waste, not into formwork; 3. Retain some grout in the hopper to be remixed with the first hopper full of concrete; 4. Fit the protecting grill on the hopper before loading concrete. When pumping is done downhill, tight plugs of damp cement bags or a sponge rubber balls should be placed before the grout to make sure that the walls of the pipe are properly lined. [5] Functionality of the Pumping Device In essence, a concrete pump places the mixed concrete at various sites by pumping the slurry. It comprises of a supporting arm which is projected at an operating position and used for positioning the conduit end of a pump conduit. A supporting arm with segments constitutes a component of the pump conduit. In order to achieve a higher lift, device provides the features that at least one of the supporting arm segments is adapted to be telescoped and can be transferred from a non-extended starting position to at least one extended position. [4] Three different kinds of pumping techniques are available to the manufacturers Boom Pump - Boom trucks are self-contained units consisting of a truck and frame, and the pump itself. Because of their reach, boom trucks often remain in the same place for an entire pour. This allows ready mix trucks to release their loads directly into the pumps hopper at one central location and helps to create a more efficient jobsite traffic flow. [1] Line Pumps - Line pumps are versatile, portable units typically used to pump not only structural concrete, but also grout, wet screeds, mortar, shotcrete, foamed concrete, and sludge. [1] Separate Placing Booms - Separate concrete placing booms can be used