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53-478: The current bridge was built in late December 1969. The bridge is 317 metres long and 23.5 metres wide, made of reinforced concrete , and its span is 56.6 metres. The bridge is an openable bascule bridge , but nowadays it is only opened on rare exceptional occasions. Formerly it used to be opened regularly to allow large cargo ships to transport coal to the pier of the Salmisaari power plant underneath it. Nowadays

106-453: A major role in the evolution of concrete construction as a proven and studied science. Without Hyatt's work, more dangerous trial and error methods might have been depended on for the advancement in the technology. Joseph Monier , a 19th-century French gardener, was a pioneer in the development of structural, prefabricated and reinforced concrete, having been dissatisfied with the existing materials available for making durable flowerpots. He

159-419: A reduction in its durability. Corrosion and freeze/thaw cycles may damage poorly designed or constructed reinforced concrete. When rebar corrodes, the oxidation products ( rust ) expand and tends to flake, cracking the concrete and unbonding the rebar from the concrete. Typical mechanisms leading to durability problems are discussed below. Cracking of the concrete section is nearly impossible to prevent; however,

212-426: A well-chosen concrete mix will provide additional protection for many applications. Uncoated, low carbon/chromium rebar looks similar to standard carbon steel rebar due to its lack of a coating; its highly corrosion-resistant features are inherent in the steel microstructure. It can be identified by the unique ASTM specified mill marking on its smooth, dark charcoal finish. Epoxy-coated rebar can easily be identified by

265-556: Is a station on Line 10 of the Paris Métro . It is located in the 15th arrondissement . The station opened as Beaugrenelle on 13 July 1913 as part of the initial section of line 8 as its temporary southern terminus, and with Opéra as its northern terminus. The line was then extended to Porte d'Auteuil on 30 September that same year, becoming its new southern terminus. It was then named after Place Beaugrenelle (now known as Place Charles Michels). Beaugrenelle ("beautiful Grenelle")

318-658: Is a mixture of coarse (stone or brick chips) and fine (generally sand and/or crushed stone) aggregates with a paste of binder material (usually Portland cement ) and water. When cement is mixed with a small amount of water, it hydrates to form microscopic opaque crystal lattices encapsulating and locking the aggregate into a rigid shape. The aggregates used for making concrete should be free from harmful substances like organic impurities, silt, clay, lignite, etc. Typical concrete mixes have high resistance to compressive stresses (about 4,000 psi (28 MPa)); however, any appreciable tension ( e.g., due to bending ) will break

371-528: Is coating them with zinc phosphate . Zinc phosphate slowly reacts with calcium cations and the hydroxyl anions present in the cement pore water and forms a stable hydroxyapatite layer. Penetrating sealants typically must be applied some time after curing. Sealants include paint, plastic foams, films and aluminum foil , felts or fabric mats sealed with tar, and layers of bentonite clay, sometimes used to seal roadbeds. Corrosion inhibitors , such as calcium nitrite [Ca(NO 2 ) 2 ], can also be added to

424-495: Is located across the bay from San Francisco . Two years later, El Campanil survived the 1906 San Francisco earthquake without any damage, which helped build her reputation and launch her prolific career. The 1906 earthquake also changed the public's initial resistance to reinforced concrete as a building material, which had been criticized for its perceived dullness. In 1908, the San Francisco Board of Supervisors changed

477-541: Is one in which both the compressive and tensile zones reach yielding at the same imposed load on the beam, and the concrete will crush and the tensile steel will yield at the same time. This design criterion is however as risky as over-reinforced concrete, because failure is sudden as the concrete crushes at the same time of the tensile steel yields, which gives a very little warning of distress in tension failure. Steel-reinforced concrete moment-carrying elements should normally be designed to be under-reinforced so that users of

530-428: Is one in which the concrete element is only reinforced near the tensile face and the reinforcement, called tension steel, is designed to resist the tension. A doubly reinforced beam is the section in which besides the tensile reinforcement the concrete element is also reinforced near the compressive face to help the concrete resist compression and take stresses. The latter reinforcement is called compression steel. When

583-430: Is one in which the tension capacity of the tension steel is greater than the combined compression capacity of the concrete and the compression steel (over-reinforced at tensile face). So the "over-reinforced concrete" beam fails by crushing of the compressive-zone concrete and before the tension zone steel yields, which does not provide any warning before failure as the failure is instantaneous. A balanced-reinforced beam

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636-579: Is the theoretical failure point with a certain probability. It is stated under factored loads and factored resistances. Reinforced concrete structures are normally designed according to rules and regulations or recommendation of a code such as ACI-318, CEB, Eurocode 2 or the like. WSD, USD or LRFD methods are used in design of RC structural members. Analysis and design of RC members can be carried out by using linear or non-linear approaches. When applying safety factors, building codes normally propose linear approaches, but for some cases non-linear approaches. To see

689-446: Is transferred from the concrete to the bar interface so as to change the tensile stress in the reinforcing bar along its length. This load transfer is achieved by means of bond (anchorage) and is idealized as a continuous stress field that develops in the vicinity of the steel-concrete interface. The reasons that the two different material components concrete and steel can work together are as follows: (1) Reinforcement can be well bonded to

742-610: The Länsiväylä highway, was built. Before the bridge there had been a ferry at the same time since 1914. The octagonal building Mutterikioski building was built to serve the ferry passengers. The building currently servers as a café . The ferry connection is also related to the island's name, as Lauttasaari means "ferry island" in Finnish. As the population of Lauttasaari grew in the 1950s with further construction and new residential districts such as Tapiola were built in southern Espoo ,

795-462: The tensile strength of concrete was improved by the reinforcing. Before the 1870s, the use of concrete construction, though dating back to the Roman Empire , and having been reintroduced in the early 19th century, was not yet a proven scientific technology. Ernest L. Ransome , an English-born engineer, was an early innovator of reinforced concrete techniques at the end of the 19th century. Using

848-697: The 1890s, Wayss and his firm greatly contributed to the advancement of Monier's system of reinforcing, established it as a well-developed scientific technology. One of the first skyscrapers made with reinforced concrete was the 16-story Ingalls Building in Cincinnati, constructed in 1904. The first reinforced concrete building in Southern California was the Laughlin Annex in downtown Los Angeles , constructed in 1905. In 1906, 16 building permits were reportedly issued for reinforced concrete buildings in

901-673: The City of Los Angeles, including the Temple Auditorium and 8-story Hayward Hotel. In 1906, a partial collapse of the Bixby Hotel in Long Beach killed 10 workers during construction when shoring was removed prematurely. That event spurred a scrutiny of concrete erection practices and building inspections. The structure was constructed of reinforced concrete frames with hollow clay tile ribbed flooring and hollow clay tile infill walls. That practice

954-592: The English counties of Norfolk and Suffolk. In 1877, Thaddeus Hyatt , published a report entitled An Account of Some Experiments with Portland-Cement-Concrete Combined with Iron as a Building Material, with Reference to Economy of Metal in Construction and for Security against Fire in the Making of Roofs, Floors, and Walking Surfaces , in which he reported his experiments on the behaviour of reinforced concrete. His work played

1007-695: The actual available length is inadequate for full development, special anchorages must be provided, such as cogs or hooks or mechanical end plates. The same concept applies to lap splice length mentioned in the codes where splices (overlapping) provided between two adjacent bars in order to maintain the required continuity of stress in the splice zone. In wet and cold climates, reinforced concrete for roads, bridges, parking structures and other structures that may be exposed to deicing salt may benefit from use of corrosion-resistant reinforcement such as uncoated, low carbon/chromium (micro composite), epoxy-coated, hot dip galvanized or stainless steel rebar. Good design and

1060-461: The actual bond stress varies along the length of a bar anchored in a zone of tension, current international codes of specifications use the concept of development length rather than bond stress. The main requirement for safety against bond failure is to provide a sufficient extension of the length of the bar beyond the point where the steel is required to develop its yield stress and this length must be at least equal to its development length. However, if

1113-539: The alkalinity of the concrete protects the steel rebar from corrosion . Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made of steel, polymers or alternate composite material in conjunction with rebar or not. Reinforced concrete may also be permanently stressed (concrete in compression, reinforcement in tension), so as to improve

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1166-472: The behavior of the final structure under working loads. In the United States , the most common methods of doing this are known as pre-tensioning and post-tensioning . For a strong, ductile and durable construction the reinforcement needs to have the following properties at least: François Coignet used iron-reinforced concrete as a technique for constructing building structures. In 1853, Coignet built

1219-543: The chief reasons for the failure of reinforcement bars in concrete. The relative cross-sectional area of steel required for typical reinforced concrete is usually quite small and varies from 1% for most beams and slabs to 6% for some columns. Reinforcing bars are normally round in cross-section and vary in diameter. Reinforced concrete structures sometimes have provisions such as ventilated hollow cores to control their moisture & humidity. Distribution of concrete (in spite of reinforcement) strength characteristics along

1272-732: The city's building codes to allow wider use of reinforced concrete. In 1906, the National Association of Cement Users (NACU) published Standard No. 1 and, in 1910, the Standard Building Regulations for the Use of Reinforced Concrete . Many different types of structures and components of structures can be built using reinforced concrete elements including slabs , walls , beams , columns , foundations , frames and more. Reinforced concrete can be classified as precast or cast-in-place concrete . Designing and implementing

1325-457: The coal harbour of the plant has been moved to the south of the bridge, where the coal is transported to a larger storage space underneath the plant, built in 2004, via an underground tunnel. The bridge has also become a popular spot for fishing Baltic herring . The first Lauttasaari bridge was built in 1935. At the same time, the Jorvaksentie road leading west of Lauttasaari, predecessor of

1378-422: The compression zone of a concrete is inadequate to resist the compressive moment (positive moment), extra reinforcement has to be provided if the architect limits the dimensions of the section. An under-reinforced beam is one in which the tension capacity of the tensile reinforcement is smaller than the combined compression capacity of the concrete and the compression steel (under-reinforced at tensile face). When

1431-541: The concrete resists compression and reinforcement " rebar " resists tension can be made into almost any shape and size for the construction industry. Three physical characteristics give reinforced concrete its special properties: As a rule of thumb, only to give an idea on orders of magnitude, steel is protected at pH above ~11 but starts to corrode below ~10 depending on steel characteristics and local physico-chemical conditions when concrete becomes carbonated. Carbonation of concrete along with chloride ingress are amongst

1484-412: The concrete roof and floors in the two-story house he was constructing. His positioning of the reinforcement demonstrated that, unlike his predecessors, he had knowledge of tensile stresses. Between 1869 and 1870, Henry Eton would design, and Messrs W & T Phillips of London construct the wrought iron reinforced Homersfield Bridge bridge, with a 50' (15.25 meter) span, over the river Waveney, between

1537-416: The concrete, thus they can jointly resist external loads and deform. (2) The thermal expansion coefficients of concrete and steel are so close ( 1.0 × 10 to 1.5 × 10 for concrete and 1.2 × 10 for steel) that the thermal stress-induced damage to the bond between the two components can be prevented. (3) Concrete can protect the embedded steel from corrosion and high-temperature induced softening. Because

1590-507: The concrete, which occurs when compressive stresses exceed its strength, by yielding or failure of the rebar when bending or shear stresses exceed the strength of the reinforcement, or by bond failure between the concrete and the rebar. Carbonation, or neutralisation, is a chemical reaction between carbon dioxide in the air and calcium hydroxide and hydrated calcium silicate in the concrete. Rue Charles Michels Charles Michels ( French pronunciation: [ʃaʁl miʃɛl] )

1643-403: The cross-section of vertical reinforced concrete elements is inhomogeneous. The reinforcement in a RC structure, such as a steel bar, has to undergo the same strain or deformation as the surrounding concrete in order to prevent discontinuity, slip or separation of the two materials under load. Maintaining composite action requires transfer of load between the concrete and steel. The direct stress

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1696-403: The examples of a non-linear numerical simulation and calculation visit the references: Prestressing concrete is a technique that greatly increases the load-bearing strength of concrete beams. The reinforcing steel in the bottom part of the beam, which will be subjected to tensile forces when in service, is placed in tension before the concrete is poured around it. Once the concrete has hardened,

1749-557: The first concrete buildings constructed in the United States was a private home designed by William Ward , completed in 1876. The home was particularly designed to be fireproof. G. A. Wayss was a German civil engineer and a pioneer of the iron and steel concrete construction. In 1879, Wayss bought the German rights to Monier's patents and, in 1884, his firm, Wayss & Freytag , made the first commercial use of reinforced concrete. Up until

1802-506: The first iron reinforced concrete structure, a four-story house at 72 rue Charles Michels in the suburbs of Paris. Coignet's descriptions of reinforcing concrete suggests that he did not do it for means of adding strength to the concrete but for keeping walls in monolithic construction from overturning. The, 1872–1873, Pippen building in Brooklyn stands as a testament to his technique. In 1854, English builder William B. Wilkinson reinforced

1855-480: The inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (known as 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,

1908-645: The knowledge of reinforced concrete developed during the previous 50 years, Ransome improved nearly all the styles and techniques of the earlier inventors of reinforced concrete. Ransome's key innovation was to twist the reinforcing steel bar, thereby improving its bond with the concrete. Gaining increasing fame from his concrete constructed buildings, Ransome was able to build two of the first reinforced concrete bridges in North America. One of his bridges still stands on Shelter Island in New Yorks East End, One of

1961-811: The light green color of its epoxy coating. Hot dip galvanized rebar may be bright or dull gray depending on length of exposure, and stainless rebar exhibits a typical white metallic sheen that is readily distinguishable from carbon steel reinforcing bar. Reference ASTM standard specifications A1035/A1035M Standard Specification for Deformed and Plain Low-carbon, Chromium, Steel Bars for Concrete Reinforcement, A767 Standard Specification for Hot Dip Galvanized Reinforcing Bars, A775 Standard Specification for Epoxy Coated Steel Reinforcing Bars and A955 Standard Specification for Deformed and Plain Stainless Bars for Concrete Reinforcement. Another, cheaper way of protecting rebars

2014-438: The microscopic rigid lattice, resulting in cracking and separation of the concrete. For this reason, typical non-reinforced concrete must be well supported to prevent the development of tension. If a material with high strength in tension, such as steel , is placed in concrete, then the composite material, reinforced concrete, resists not only compression but also bending and other direct tensile actions. A composite section where

2067-656: The most efficient floor system is key to creating optimal building structures. Small changes in the design of a floor system can have significant impact on material costs, construction schedule, ultimate strength, operating costs, occupancy levels and end use of a building. Without reinforcement, constructing modern structures with concrete material would not be possible. When reinforced concrete elements are used in construction, these reinforced concrete elements exhibit basic behavior when subjected to external loads . Reinforced concrete elements may be subject to tension , compression , bending , shear , and/or torsion . Concrete

2120-454: The old bridge soon became too narrow. Large traffic jams appeared on both sides of the bridge. The situation eased significantly when the Lapinlahti bridge , part of Länsiväylä, was built north of the bridge in 1965. The old Lauttasaari bridge was dismantled in the winter from 1967 to 1968 and construction of the new bridge started soon afterwards. It was completed in late December 1969. There

2173-448: The passivation of steel at the anodic oxidation sites. Nitrite is a much more active corrosion inhibitor than nitrate , which is a less powerful oxidizer of the divalent iron. A beam bends under bending moment , resulting in a small curvature. At the outer face (tensile face) of the curvature the concrete experiences tensile stress, while at the inner face (compressive face) it experiences compressive stress. A singly reinforced beam

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2226-433: The reinforced concrete element is subject to increasing bending moment, the tension steel yields while the concrete does not reach its ultimate failure condition. As the tension steel yields and stretches, an "under-reinforced" concrete also yields in a ductile manner, exhibiting a large deformation and warning before its ultimate failure. In this case the yield stress of the steel governs the design. An over-reinforced beam

2279-581: The size and location of cracks can be limited and controlled by appropriate reinforcement, control joints, curing methodology and concrete mix design. Cracking can allow moisture to penetrate and corrode the reinforcement. This is a serviceability failure in limit state design . Cracking is normally the result of an inadequate quantity of rebar, or rebar spaced at too great a distance. The concrete cracks either under excess loading, or due to internal effects such as early thermal shrinkage while it cures. Ultimate failure leading to collapse can be caused by crushing

2332-558: The station as well as the nearby Place Beaugrenelle were renamed Charles Michels and Place Charles Michels respectively, in honour of Charles Michels (1903–1941), a trade unionist, communist militant, and deputy of the 15th arrondissement in Paris . He was held hostage and shot during the Occupation by the Nazis in retaliation for the assassination of Karl Hotz , amongst 44 other people. Hence,

2385-552: The station was used by 4,601,730 passengers, making it the 93rd busiest of the Métro network out of 302 stations. In 2020, the station was used by 2,198,392 passengers amidst the COVID-19 pandemic , making it the 194th busiest of the Métro network out of 108 stations. In 2021, the station was used by 3,079,569 passengers, making it the 102nd busiest of the Métro network out of 305 stations. The station has 2 accesses: The station has

2438-650: The station, along with 7 other stations, were renamed after the Second World War to honour the resistance fighters who had died for France. The other stations were: Colonel Fabien , Corentin Cariou , Corentin Celton , Guy Môquet , Jacques Bonsergent , Marx Dormoy , and Trinité - d'Estienne d'Orves . As part of the "Renouveau du métro" programme by the RATP , the station's platforms were renovated and modernised in 2009. In 2019,

2491-468: The structure will receive warning of impending collapse. The characteristic strength is the strength of a material where less than 5% of the specimen shows lower strength. The design strength or nominal strength is the strength of a material, including a material-safety factor. The value of the safety factor generally ranges from 0.75 to 0.85 in Permissible stress design . The ultimate limit state

2544-454: The tension on the reinforcing steel is released, placing a built-in compressive force on the concrete. When loads are applied, the reinforcing steel takes on more stress and the compressive force in the concrete is reduced, but does not become a tensile force. Since the concrete is always under compression, it is less subject to cracking and failure. Reinforced concrete can fail due to inadequate strength, leading to mechanical failure, or due to

2597-403: The water mix before pouring concrete. Generally, 1–2 wt. % of [Ca(NO 2 ) 2 ] with respect to cement weight is needed to prevent corrosion of the rebars. The nitrite anion is a mild oxidizer that oxidizes the soluble and mobile ferrous ions (Fe ) present at the surface of the corroding steel and causes them to precipitate as an insoluble ferric hydroxide (Fe(OH) 3 ). This causes

2650-469: Was a name given by property developers in the Grenelle district during its urbanisation. On 27 July 1937, the section of line 8 between La Motte-Picquet–Grenelle and Porte d'Auteuil , including Beaugrenelle , was transferred to line 10 during the reconfiguration of lines 8, 10, and the old line 14 . On 29 July 1937, line 10 was extended from Duroc to La Motte-Picquet–Grenelle . On 14 July 1945, both

2703-421: Was a temporary wooden pedestrian bridge to the north of the bridge during its construction. 60°09′39.6″N 24°53′45.6″E  /  60.161000°N 24.896000°E  / 60.161000; 24.896000 Reinforced concrete Reinforced concrete , also called ferroconcrete , is a composite material in which concrete 's relatively low tensile strength and ductility are compensated for by

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2756-404: Was granted a patent for reinforcing concrete flowerpots by means of mixing a wire mesh and a mortar shell. In 1877, Monier was granted another patent for a more advanced technique of reinforcing concrete columns and girders, using iron rods placed in a grid pattern. Though Monier undoubtedly knew that reinforcing concrete would improve its inner cohesion, it is not clear whether he even knew how much

2809-422: Was strongly questioned by experts and recommendations for "pure" concrete construction were made, using reinforced concrete for the floors and walls as well as the frames. In April 1904, Julia Morgan , an American architect and engineer, who pioneered the aesthetic use of reinforced concrete, completed her first reinforced concrete structure, El Campanil, a 72-foot (22 m) bell tower at Mills College , which

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