Concrete Pumping Information

CONCRETE PUMPING HISTORY

A concrete pump is a tool used for transferring liquid concrete by pumping. There are five types of concrete pumps. Although no definitive record exists documenting the first use of a concrete pump, the first patent for a concrete pump was established in 1913 in the U.S. Germany became the leading technology innovators in concrete pump development, and used the method extensively for the reconstruction efforts after World War II. West Germany and Japan held the largest Manufacturing companies of concrete pumps throughout the 1980's and 90's. Today there are many countries including the U.S. that are participants in the manufacturing of concrete pumps on a mass scale. Many of the largest and most complex construction endeavors since World War II, Would not have been possible without the versatility and extended delivery methods provided by the concrete pump units. Skyscrapers, dams, large bridge pilings, and extended tunnels are poured using concrete pumps. Many types of concrete pumps are used, however typically there are five that are the most widely used in construction that requires concrete pumping operations. The boom pump, placement boom, truck-mounted line pump, trailer mounted line pump, skid-mounted line pump. Each of these five types of concrete pumps provide their very own unique method of application depending on the needs of the job.

CONCRETE PUMPING ADVANTAGES

Pumping concrete in place allows for improved construction times, reduced cost, and more aggressive engineering projects to be accomplished than would ever be possible without it. The concrete pump placing method also allows for quicker return on investment for companies and individuals hiring the concrete work, as efficiency is greatly improved.

CONCRETE PUMPING WORLD RECORD

The world record for vertical concrete pumping was achieved in India by Schwing Stetter in August 2009.Concrete was pumped to a height of 715m or 2, 345.80052 ft for the construction of the Parbati hydro-electric power project in the Indian state of Himachal Pradesh.

FIVE TYPES OF CONCRETE PUMPS

TRUCK-MOUNTED BOOM CONCRETE PUMP

The first type of concrete pump is attached to a truck. It is known as a truck-mounted boom concrete pump because it uses a wireless remote-controlled articulating robotic arm (called a boom) to place concrete with pinpoint accuracy. Boom pumps can be found in various sizes and are used on most of the larger construction projects such as high rise buildings as they are capable of pumping at very high volumes and because of the labor saving nature of the placing boom. They are a revolutionary alternative to the truck-mounted concrete line pumps. Some hydraulically driven boom concrete pump models have pumped structural concrete at outputs exceeding 150 cubic yards per hour. Boom trucks are self-contained units consisting of a truck and frame, and the pump itself. Boom trucks are used for concrete pours for everything from slabs and medium high-rise buildings, to large volume commercial and industrial projects. They range from single-axle truck mounted pumps used for their high maneuverability, suitability for confined areas, and cost/performance value, to huge, six-axle rigs used for their powerful pumps and long reach on high-rise and other large-scale projects. Booms for these trucks can come in configurations of three and four sections, with a low unfolding height of about 16 feet. This low unfolding height is ideal for placing concrete in confined areas. Longer, five-part booms can reach up or out more than 200 feet. Because of their reach, boom trucks often remain in the same place for an entire pour. This allows ready mix trucks to discharge their loads directly into the pumps hopper at one central location and helps to create a more efficient jobsite traffic flow. Most manufacturers offer a variety of options, from chassis and pump size, to boom configurations, remote control, and outrigger options.

PLACEMENT BOOM CONCRETE PUMP

The second type of concrete pump is known as a placement boom and basically has the same guts inside as the truck-mounted boom concrete pump and operate similarly. These types of booms are used on jobs where the confines of the construction site will not permit the use of a larger boom or line pump. Placement booms are usually placed on the jobsite with a large crane, in many cases on top of a multi-story building as its being constructed and moving up into the sky. Placement booms are the ideal method of choice for placement of concrete during multi-story building projects. Separate concrete placing booms can be used when a boom truck is unavailable, or in situations where the boom truck may not be able to conveniently access the pour site. Combined with the right concrete pump, these placing booms provide a systematic method of concrete distribution. For instance, contractors use the truck-mounted pump with placing boom in its conventional mode for part of a day on slab pours or other ground level placements and quickly remove the boom (with the aid of a tower crane) for remote placements later in the day. Typically, the boom is remounted on a pedestal, which can be located hundreds of feet from the pump and connected with a pipeline. Here are some mounting options for placing booms: Cross frame: Foundation mounting with bolted cross frame. Crane tower mount: Boom and mast mounted on crane tower. Side mount: Mast mounted to the side of a structure with brackets. Wedge mount: Boom and mast inserted in floor slab with wedges. Ballasted cross frame: Zero elevation ballasted cross frame. Ballasted methods may also use the boom mounted on a freestanding mast. Anchored: Boom and mast are anchored to a supporting surface.

TRUCK-MOUNTED LINE CONCRETE PUMP

The third type of concrete pump is skid mounted on a flatbed truck and known as a truck-mounted line pump, truck-mounted slick line pump, truck-mounted concrete pump, or city pump, and is used in the same fassion as a trailer-mounted concrete pump. These pumps require steel or rubber concrete placing hoses to be manually attached to the outlet of the machine. Those hoses are linked together and lead to wherever the concrete needs to be placed. Line pumps normally pump concrete at lower volumes than boom pumps and are used for smaller volume concrete placing applications such as swimming pools, sidewalks, and single family home concrete slabs and most ground slabs. These types of pumps are usually wireless remote-controlled but can also be bypassed and used manually through the pumps electrical box controller.

TRAILER-MOUNTED LINE CONCRETE PUMP

The fourth type of concrete pump is placed on a trailer, and it is commonly referred to as a line pump, slick line pump, or trailer-mounted concrete pump. These pumps require steel or rubber concrete placing hoses to be manually attached to the outlet of the machine. Those hoses are linked together and lead to wherever the concrete needs to be placed. Line pumps normally pump concrete at lower volumes than boom pumps and are used for smaller volume concrete placing applications such as swimming pools, sidewalks, and single family home concrete slabs and most ground slabs. These types of pumps are usually wireless remote-controlled but can also be bypassed and used manually through the pumps electrical box controller.

SKID MOUNTED LINE CONCRETE PUMP

The fifth type of concrete pumps are skid or rail mounted concrete pumps, usually transported and moved around by forklifts or cranes. These pumps are used the same as truck-mounted and trailer mounted concrete line pumps and require steel or rubber concrete placing hoses to be manually attached to the outlet of the machine. Those hoses are linked together and lead to wherever the concrete needs to be placed. These pumps normally pump concrete at lower volumes than boom pumps and are used for smaller volume concrete placing applications such as underground concrete pumping, shotcreting, and grout pumping. These types of pumps are usually wireless remote-controlled but can also be bypassed and used manually through the pumps electrical box controller. These pumps go where truck and trailer mounted pumps cannot. These types of pumps perform well in mines and tunnels because of their compact nature. These pumps are uncommon except on specialized jobsites such as mines and tunnels.

SHOTCRETE PUMPING

Shotcrete is typically placed by a concrete pump to move high volumes or to pump with ease, or by a grout pump with low volumes and less ease.

SHOTCRETE

Shotcrete and gunite are two commonly used terms for substances applied via pressure hoses. Shotcrete is concrete (or sometimes mortar) conveyed through a hose and pneumatically projected at high velocity onto a surface. Shotcrete undergoes placement and compaction at the same time due to the force with which it is projected from the nozzle. It can be impacted onto any type or shape of surface, including vertical or overhead areas. Shotcrete also known as Sprayed concrete, is reinforced by conventional steel rods, steel mesh, and/or fibers. Fiber reinforcement (steel or synthetic) is also used for stabilization in applications such as slopes or tunneling.

HISTORY

Shotcrete was invented in the early 1900s by American taxidermist Carl Akeley, used to fill plaster models of animals. He used the method of blowing dry material out of a hose with compressed air, wetting it as it was released. This was later used to patch weak parts in old buildings. In 1911, he was granted a patent for his inventions, the "cement gun", the equipment used, and "gunite", the material that was produced. Until the 1950s when the wet-mix process was devised, only the dry-mix process was used. In the 1960s, the alternative method for gunning by the dry method was devised with the development of the rotary gun, with an open hopper that could be fed continuously.

NOZZLEMAN

The nozzleman is the person controlling the nozzle that delivers the concrete to the surface. The nozzle is controlled by hand on small jobs, for example the construction of small swimming pools. On larger work the nozzle is held by mechanical arms and the nozzleman controls the operation by a hand-held remote control.

GUNITE/ THE DRY MIX METHOD

The dry mix method involves placing the dry ingredients into a hopper and then conveying them pneumatically through a hose to the nozzle. The nozzleman controls the addition of water at the nozzle. The water and the dry mixture is not completely mixed, but is completed as the mixture hits the receiving surface. This requires a skilled nozzleman, especially in the case of thick or heavily reinforced sections. Advantages of the dry mix process are that the water content can be adjusted instantaneously by the nozzleman, allowing more effective placement in overhead and vertical applications without using accelerators. The dry mix process is useful in repair applications when it is necessary to stop frequently, as the dry material is easily discharged from the hose.

SHOTCRETE/ THE WET MIX METHOD

Wet-mix shotcrete involves pumping of a previously prepared concrete, typically ready-mixed concrete, to the nozzle. Compressed air is introduced at the nozzle to impel the mixture onto the receiving surface. The wet-gun procedure generally produces less rebound, waste (when material falls to the floor), and dust compared to the dry-mix procedure. The greatest advantage of the wet-mix process is that larger volumes can be placed in less time. Shotcrete vs. gunite, Shotcrete comes out the winner in volumes. Shotcrete to be applied by this mithod is pre-mixed to a specific consistency with an exact recipe that determines the spray pattern as well as the set-up time of the concrete to be applied. The Concrete Spray method known as Shotcrete is used for constructing retainer walls, swimming pools, and other Standing structures. Shotcrete is used widely in tunneling and mining opperations to stabilize and shore up the roofs and walls of tunnel and mine shafts.

SHOTCRETE TODAY

Shotcrete is today an all-inclusive term that describes spraying concrete or mortar with either a dry or wet mix process. However, it may also sometimes be used to distinguish from gunite as a wet-mix. The term shotcrete was first defined by the American Railway Engineers Association (AREA) in the early 1930s. By 1951, Shotcrete had become the official generic name of the sprayed concrete process. Versatility is such a broad word in the Shotcrete World. For nearly a century, Shotcrete has been in many applications on the most diverse projects. Whether you’re an engineer, project owner, contractor, or tradesman, Shotcrete can be applied in many projects where concrete is being used. Shotcrete can save time and money more often than not. Though Shotcrete is many times associated with the mining industry, it is also used in projects such as, swimming pools, soil nailing, arch culverts, subgrade retaining walls, road construction and stabilization, as well as unique architectural enhancements. The Shotcrete wet-mix seems to have nearly replaced guite as the preferred process of today.

GUNITE

Gunite refers only to the dry-mix process, in which the dry cementitious mixture is blown through a hose to the nozzle, where water is injected immediately before application. Gunite was the original term coined before Shotcrete by Akeley, trademarked in 1909 and patented in North Carolina. The concrete is blasted by pneumatic pressure from a gun, hence "gun"-ite.

ALLENTOWN AND GUNITE

The term "Gunite" became the registered trademark of Allentown, the oldest manufacturer of gunite equipment. Other manufacturers were thus compelled to use other terminology to describe the process such as shotcrete, pneumatic concrete, guncrete, etc. Shotcrete emerged as the most commonly used term other than gunite, and after the later development of the wet process came to be used for both methods wet or dry...

GROUT PUMPING

A ball-valve grout pump is a tool used for transferring liquid concrete by pumping. Though both employ Ball-Valve Technology, there are two types of grout pumps. Smaller pumps are called grout pumps, and the larger ones are called hydraulic grout pumps and are hydraulically driven.

BALL-VALVE GROUT PUMP (AKA) BALL-VALVE CONCRETE PUMP

Grout pumps are versatile, usually small, lightweight, and are portable trailer units typically used to pump not only grout into masonry walls and footings; but also wet screeds, mortar, shotcrete, foamed concrete, sand slurry, pure liquid concrete, and sludge. Grout pumps are also used as a tool in pressure grouting applications. Most small pump operations typically employ ball-valve-type pumps. While the smaller models are often called grout pumps, many larger hydraulically driven models can be used for structural concrete and shotcreting where low-volume output is suitable. They're also used for repairing underwater concrete, filling fabric forms, placing concrete in heavily reinforced sections, and building bond beams for masonry walls. Cost for ball-valve pumps are relatively low and there are few wear parts. Because of its simple design, the pump is easy to clean and maintain. The units are small and maneuverable, and the hoses easy to handle. These pumps require steel or rubber concrete and grout placing hoses to be manually attached to the outlet of the machine. Those hoses are linked together and lead to wherever the concrete or grout needs to be placed. These units pump at much lower volumes than concrete line and boom pumps and are used for smaller volume concrete placing applications. These types of pumps are usually wire-connected-remote-controlled through a wire connection at the pumps electrical box controller. Some however are wireless remote controlled.

How Does a Concrete Pump Truck work?
A concrete mixer truck backs up to the back of a pump truck and discharges its load into the hopper. The hopper feeds the concrete through a pump which applies pressure to a column of a pipe, forcing the concrete through a lubricated hose.
Concrete pumps are often used to reach places that are difficult or impossible to reach by other concrete placement methods, such as backyard swimming pools or high-rise buildings.. Pumping is also used when the space available for construction equipment is limited. Approximately 1/4 of all concrete placed in the United States is placed by concrete pumping.
What are the advantages in using Concrete Pump Trucks?

  • Pumping placement is faster than placement by other methods (wheelbarrow, tailgating, or a skidster loader)
  • Pumped concrete can be placed in areas that are difficult or impossible to reach by other placement methods.
  • Pumping often results in a savings in manpower, equipment cost and cycle time.
  • Pumping can take place under any weather conditions, including snow and rain, since the concrete is protected from the elements during transport to the placement area.
  • Pumping can be used when the space available for construction equipment is limited.
  • Pumping concrete frees cranes and hoists for other construction operations, such as delivering materials.
  • Pumped concrete can be easier to handle because the flow of concrete is directed to the exact spot of placement (whereas cranes and conveyors deposit large piles of concrete that must be moved manually).
  • Few obstacles can block a concrete pumping pipeline. Pipelines can corner sharply, pass through narrow spaces, travel over or under walls, etc.
  • A continuous supply of pumped concrete can help set a steady work pace for the placement crew, thereby increasing productivity.
  • A contractor can vary the placement speed or add lines to fit the pace of the job.
  • Flow of concrete remains steady and controlled.
  • Pumping concrete allows a contractor to place floor slabs on upper floors before completing the concrete work on lower floors. This provides protection from weather when working on lower floors.
  • For large pours, multiple pumps can be set up, allowing several trucksto discharge at the same time.

Concrete Pumps can place up to 220 yards of concrete Per Hour.
Effective pumping distances range from 10 feet to 1000 feet horizontally, as well as from 10 to 1000 feet vertically.
Concrete Pumping Equipment required: concrete pump, heavy-duty pipe, hose, and accessories.
The most important considerations relating to the pumping of concrete are:

  • The concrete mix design
  • The pump location

Concrete Mix Design for Concrete Pumps
The concrete mix design must be correctly proportioned so that the concrete will flow easily and uniformly through the pipe. The pipeline diameter should be 3-1/2 to 4 times greater than the maximum aggregate size for pumped concrete. This helps ensure that the pipeline will not become clogged. Another factor in mix design is the slump of the pumped concrete. A higher slump will cause concrete to flow more readily, making the concrete easier to pump.

However, an excessively high slump can cause the concrete to separate, resulting in plugs in the pump or line. What makes concrete pumpable? Pumpable concrete can be pushed under pressure through a pipeline as a cylinder, separate from the pipeline wall by a lubricating layer of water, cement, and sand (mortar). A concrete mix must be such that the concrete can pass through reducers in the pipeline system, and can go around bends in the line. In order to obtain this type of pumpability, the mix must be dense, cohesive, and have sufficient mortar. (Mortar required depends on the line size, efficiency of concrete pump, and pressure available for pumping concrete).

Concrete Pump Location
The most important consideration relating to pump location is pump accessibility. Ideally, space for two concrete trucks - one unloading and one ready to unload - should be provided at the pump hopper. Usually, pumps should be located as closely as possible to the area to be concreted last.

Effects of Weather Extremes
Hot Weather: Since concrete sets faster in hot weather, slow or intermittent pumping is necessary if delays in placement are anticipated. Also, wet burlap can be wrapped around pipelines to cool the concrete by evaporation.
Cold Weather: During cold weather, concrete is in danger of freezing in exposed lines. Exposed lines should be run through enclosures or wrapped in insulation to prevent freezing.