An ironworker is a tradesman who works in the iron-working industry. Ironworkers assemble the structural framework in accordance with engineered drawings and install the metal support pieces for new buildings. They also repair and renovate old structures using reinforced concrete and steel. Ironworkers may work on factories, steel mills, and utility plants.
A structural/ornamental ironworker fabricates and erects (or even dismantles) the structural steel framework of pre-engineered metal buildings, single and multi-story buildings, stadiums, arenas, hospitals, towers, wind turbines, and bridges.[1][2] Ironworkers also unload, place and tie reinforcing steel bars, (rebar) as well as install post-tensioning systems, both of which give strength to the concrete used in piers, footings, slabs, buildings, and bridges. Ironworkers load, unload, place, and set machinery and equipment as well as operate power hoists, forklifts, and aerial lifts. They unload, place, and fasten metal decking, safety netting, and edge rails to facilitate safe working practices. Ironworkers finish buildings by erecting curtain wall and window wall systems, stairs and handrails, metal doors, and sheeting and elevator fronts. Ironworkers perform all types of industrial maintenance as well.[3]
Practically overnight, carpenters who built wooden bridges became ironworkers by the 1880s. It was seen as a new, exciting job for pioneers in America, despite its dangers. A worker could risk his life on high structures for about two dollars per day.[4]
The production of cast iron parts in larger and larger sizes brought about the use of cranes. This heavy equipment was used in the early 1900s to construct high structures and buildings. They used cranes to lift steel girders into place and used rivets to connect the girders to the columns of a structure. The mortality rate of men working in this trade was the highest of all trades and they would be lucky to go 10 years without a serious or fatal injury. [citation needed]
In the late 19th century, workers formed the International Union of Ironworkers because of concerns they had about safety on-the-job and the lack of protection from employers. The union's first order of business was to give widows of ironworkers $50 to cover the costs of a funeral and to give disabled ironworkers $5 a week to compensate for lost wages. With the increase in benefits from unionization, the Union greatly increased its presence in numbers in the early 1900s. Approximately 10,000 workers were considered Union Ironworkers.[4]
In the early 1900s, during the third great immigration wave,[5] the Ironworker wage in real 2010 US dollars was $9.50 (2010) to $12 (2010) per hour (40 to 50 cents an hour in 1900). Following the imposition of immigration quotas in 1921[5] wages rose to $17.50 (2010) an hour ($1.37) for a structural ironworker just prior to the Great Depression, and the real wage subsequently only dropped 10% to $16.00 (2010) ($1.05) given the deflation during the depression. However, following the wartime destruction of manufacturing complexes - with the exception of North America, 1956 wages for structural, ornamental, and rebar ironworkers rose to $27.30 (2010) an hour ($3.40). By 1970, through the Cold war buildup, iron worker wages peaked at $44.80 (2010) ($7.97). Then, following the 1965 new immigration policy and the start of the fourth great migration wave,[5] wages fell 10% to $40.38 (2010) by 1980 ($15.26), and fell another 20% to $29.90 (2010) per hour ($20.88) by 1990, comparable to the 1950s wage rate. With the end of the Cold War buildup in 1991, ironworker rates have since stayed constant and were $29.30 (2010) an hour ($24.15) in 2002.[6] In 2010 the mean wage for Ohio ironworkers, both union and nonunion, was $24.66 per hour; the 75th percentile for the nation was $29.51[7] - likely for the unionized workforce and indicates that for the past 20 years, Ironworker wages have been stagnant for various reasons,[8] - most prominently the offset in real wages created by debt, today 126% of their income compared to 40% in 1952,[9] allowing short-term survival on less than the living wage.
A reinforcing (rebar) ironworker, colloquially known as a rodbuster, works with reinforcing bars to make structures based on a certain design. Reinforcing ironworkers assemble structures with reinforcing bars by tying the bars together with tie wire. They place the rebar inside of forms, so concrete can be poured over top of them to form a solid structure. When reinforcing floors, concrete blocks are used to raise the rebar off of the deck, so no rebar can be seen underneath of the deck of the floor after the forms are stripped. In addition, ironworkers often have to cut the steel that they have for a job to fit into certain positions. For example, the rebar will have to be cut with a cutting torch, so it can fit around a drain. In some instances, welded wire fabric is used to help strengthen concrete; however, it is difficult to place this fabric in the concrete because it must be placed while the concrete is being poured into the forms.[11]
The average pay for a reinforcing bar ironworker in residential construction was an hourly wage of $23.59 in early 2009, and rebar ironworkers in commercial and industrial construction earned an hourly wage of $39.11.[12]
The typical tools of a reinforcing bar ironworker are pliers, tie wire reels, rodbuster bags, and rebar hooks. The main tool of a reinforcing bar ironworker are their work pliers. The pliers cuts soft annealed rebar tie wire and twist the wire into place. The pliers have a hook bend handle, and a spring in between the handles for self-opening of the pliers. The pliers cut ACSR, screws, nails and most hardened wires. Also, the pliers are finished with a black oxide paint to resist rust on the tool. A tie wire reel is a lightweight aluminum alloy mechanism used for dispensing tie wire efficiently. A rod buster bag is a split-leather double bottom pouch used for holding tools while they are not in use. A rebar hook is a hook made of solid steel that has a snap hook in front, and fits onto a tool belt easily.
The British call a reinforcing ironworker a steel fixer. In the United Kingdom and Ireland a steel fixer's main tool is the pincer-like nips.
Structural ironworker
Before construction can begin, the structural ironworkers have to put together cranes in order to lift the steel columns, beams, and girders according to structural blueprints. To hoist the steel, structural ironworkers use cables connected to the crane to lift the beams onto the steel columns. A rope called a tagline is attached to the beams so an ironworker can control them when needed. The crane hoists steel into place, and the ironworkers position the beams with spud wrenches to align bolt holes. Then the beams can be bolted to the steel columns. This process is continued until there are no beams or columns left to construct the structure.[13] Structural ironworkers also erect joist girders, bar joists, and trusses, and also install metal decking.
When one bullpin is inadequate, the Ratliff Technique may be utilized in order to force a bullpin to align itself straight with a hole, by driving another bullpin or driftpin between a steel member, and the first bullpin.Bullpin driven in to a hole.
The average annual income for a structural ironworker in the early 2000s was 15.85 dollars per hour; however, a full-time structural ironworker could make 30-40 dollars per hour, depending on the location of the work site.[12] The current wages for the Local Union #1 Chicago Ironworkers can be found at the Chicago Ironworkers local union website.[14]
The typical structural ironworker's tools are the spud wrench, bolt bag, sleever bars, bull pins, drift pins, and beaters. The spud wrench is the most important tool of a structural ironworker because it serves dual purposes. It is a wrench to tighten bolts, and the opposite end of the wrench can be used to align holes of beams with columns. It is made from a steel alloy, and it has a gradual taper to easily align bolt holes on beams. The bolt bag is a heavy canvas bag used for storing bolts and nuts that erect a structure. A sleever bar is a steel alloy bar used to pry on beams to put them in place, when a spud wrench is insufficient. A beater is forged steel head mallet with a lacquered hickory handle for beating a tapered pin or bull pin into the bolt hole to align the others at the beam end or "point" and stuff the rest of the holes. Drift pins have a tapper on both ends and get to be the largest diameter in the center and are used for aligning holes made up of multiple plates.
Although use of fall harnesses has reduced fatalities in this sector over time, structural steel erection remains one of the most dangerous occupations in construction. Workplace accidents claim the lives of approximately 38 out of every 100,000 full-time ironworkers each year.[15]
Ornamental ironworker
Ornamental ironworkers install metal windows into structures, erect curtain walls and window wall systems that cover the steel, erect metal stairways, cat walks, gratings, ladders, doors of all types, railings, fencing, gates, metal screens, elevator fronts, platforms, and entranceways. A variety of materials are used to make these structures and this type of work is fastened by welding or bolting to the main structure. A common name for an ornamental ironworker is a finisher because they are responsible for finishing the structures after the structural and rebar work is done.[16]
The main wage for ornamental ironworkers ranges from $20.89 per hour to $45.00 per hour. The wages are adjusted according to the location of the work and the nature of the work.
The main tool of the ornamental ironworker is an arc welder. Welding and burning equipment are considered "tools of the trade.” However, any ironworker must be certified to weld on a project.[16][17]
1 2 "Ornamental Ironworkers". Ironworker. International Association of Bridge, Structural, Ornamental, and Reinforcing Ironworkers. Archived from the original on 2011-11-28. Retrieved 2009-04-05.
Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron(III) oxides (Fe2O3·nH2O) and iron(III) oxide-hydroxide (FeO(OH), Fe(OH)3), and is typically associated with the corrosion of refined iron.
Reinforced concrete, also called ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel bars (rebar) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as a technique to reinforce the concrete. In terms of volume used annually, it is one of the most common engineering materials. In corrosion engineering terms, when designed correctly, the alkalinity of the concrete protects the steel rebar from corrosion.
Rebar, known when massed as reinforcing steel or steel reinforcement, is a steel bar used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and aid the concrete under tension. Concrete is strong under compression, but has low tensile strength. Rebar significantly increases the tensile strength of the structure. Rebar's surface features a continuous series of ribs, lugs or indentations to promote a better bond with the concrete and reduce the risk of slippage.
Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. With better understanding of seismic demand on structures and with recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged. Prior to the introduction of modern seismic codes in the late 1960s for developed countries and late 1970s for many other parts of the world, many structures were designed without adequate detailing and reinforcement for seismic protection. In view of the imminent problem, various research work has been carried out. State-of-the-art technical guidelines for seismic assessment, retrofit and rehabilitation have been published around the world – such as the ASCE-SEI 41 and the New Zealand Society for Earthquake Engineering (NZSEE)'s guidelines. These codes must be regularly updated; the 1994 Northridge earthquake brought to light the brittleness of welded steel frames, for example.
This page is a list of construction topics.
The International Association of Bridge, Structural, Ornamental and Reinforcing Iron Workers is a union in the United States and Canada, which represents, trains and protects primarily construction workers, as well as shipbuilding and metal fabrication employees.
Steel frame is a building technique with a "skeleton frame" of vertical steel columns and horizontal I-beams, constructed in a rectangular grid to support the floors, roof and walls of a building which are all attached to the frame. The development of this technique made the construction of the skyscraper possible. Steel frame has displaced its predecessor, the iron frame, in the early 20th century.
Formwork is molds into which concrete or similar materials are either precast or cast-in-place. In the context of concrete construction, the falsework supports the shuttering molds. In specialty applications formwork may be permanently incorporated into the final structure, adding insulation or helping reinforce the finished structure.
In metalworking, a drift pin, drift pin punch, simply drift, is the name for a tool used for localizing a hammer blow. A drift is smaller in diameter than the hammer face, thus concentrating the force into a smaller area. A drift is also used where the surrounding surfaces need to be protected from the hammer blow.
Structural steel is a category of steel used for making construction materials in a variety of shapes. Many structural steel shapes take the form of an elongated beam having a profile of a specific cross section. Structural steel shapes, sizes, chemical composition, mechanical properties such as strengths, storage practices, etc., are regulated by standards in most industrialized countries.
Concrete cover, in reinforced concrete, is the least distance between the surface of embedded reinforcement and the outer surface of the concrete. The concrete cover depth can be measured with a cover meter. The purpose of concrete cover is to protect the reinforcement from corrosion, fire, and other potential damage.
A steel fixer is a tradesman who positions and secures steel reinforcing bars, also known as rebar, and steel mesh used in reinforced concrete on construction projects.
A rebar spacer is a short, rod-like device used to secure reinforcing steel bars, or rebar, within cast assemblies for reinforced concrete structures. The rebar spacers are fixed before the concrete is poured and remain within the structure.
The history of structural engineering dates back to at least 2700 BC when the step pyramid for Pharaoh Djoser was built by Imhotep, the first architect in history known by name. Pyramids were the most common major structures built by ancient civilizations because it is a structural form which is inherently stable and can be almost infinitely scaled.
A T-beam, used in construction, is a load-bearing structure of reinforced concrete, wood or metal, with a capital 'T'-shaped cross section. The top of the T-shaped cross section serves as a flange or compression member in resisting compressive stresses. The web of the beam below the compression flange serves to resist shear stress. When used for highway bridges the beam incorporates reinforcing bars in the bottom of the beam to resist the tensile stresses which occur during bending.
Structural engineering depends on the knowledge of materials and their properties, in order to understand how different materials resist and support loads.
A bolt is an externally helical threaded fastener capable of being tightened or released by a twisting force (torque) to a matching nut. The bolt has an external male thread requiring a matching nut with a pre-formed female thread.
The reinforcement of 3D printed concrete is a mechanism where the ductility and tensile strength of printed concrete are improved using various reinforcing techniques, including reinforcing bars, meshes, fibers, or cables. The reinforcement of 3D printed concrete is important for the large-scale use of the new technology, like in the case of ordinary concrete. With a multitude of additive manufacturing application in the concrete construction industry—specifically the use of additively constructed concrete in the manufacture of structural concrete elements—the reinforcement and anchorage technologies vary significantly. Even for non-structural elements, the use of non-structural reinforcement such as fiber reinforcement is not uncommon. The lack of formwork in most 3D printed concrete makes the installation of reinforcement complicated. Early phases of research in concrete 3D printing primarily focused on developing the material technologies of the cementitious/concrete mixes. These causes combined with the non-existence of codal provisions on reinforcement and anchorage for printed elements speak for the limited awareness and the usage of the various reinforcement techniques in additive manufacturing. The material extrusion-based printing of concrete is currently favorable both in terms of availability of technology and of the cost-effectiveness. Therefore, most of the reinforcement techniques developed or currently under development are suitable to the extrusion-based 3D printing technology.
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