Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
  • E01D19/00—Structural or constructional details of bridges
  • E01D19/02—Piers; Abutments ; Protecting same against drifting ice
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B23/00—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects
  • B28B23/0056—Means for inserting the elements into the mould or supporting them in the mould
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B23/00—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects
  • B28B23/02—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects wherein the elements are reinforcing members
  • B28B23/022—Means for inserting reinforcing members into the mould or for supporting them in the mould
  • B28B23/024—Supporting means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B7/00—Moulds; Cores; Mandrels
  • B28B7/16—Moulds for making shaped articles with cavities or holes open to the surface, e.g. with blind holes
  • B28B7/162—Moulds for making shaped articles with cavities or holes open to the surface, e.g. with blind holes for building blocks or similar block-shaped articles
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
  • E01D21/00—Methods or apparatus specially adapted for erecting or assembling bridges
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
  • E01D2101/00—Material constitution of bridges
  • E01D2101/20—Concrete, stone or stone-like material
  • E01D2101/24—Concrete
  • E01D2101/26—Concrete reinforced
  • E01D2101/268—Composite concrete-metal
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
  • E01D2101/00—Material constitution of bridges
  • E01D2101/40—Plastics

Definitions

• the present invention relates to a method for constructing precast concrete segments capable of forming assemblies thereof by means of steel ducts. More specifically, the present invention relates to a method for a facile and precise construction of precast concrete segments used in such applications as precast concrete piers. These precast concrete segments have a novel structure wherein a steel duct, which doubles as a shear key, is integrated therein for the installation of tendons to provide sufficient resistance against shearing force as well as facile segment assemblies for the final structure.
• Shear keys are an important structural element in the generation of shear resistance among precast concrete segments.
• the present inventors have developed a method for constructing precast concrete segments in order to achieve a facile production of undamaged shear keys.
• a steel duct is placed inside a precast concrete segment in such a manner that said steel duct runs through the concrete segment, and the upper part of said steel duct protrudes outwards.
• Figure 1 illustrates a perspective view of the inventive precast concrete segment 10 equipped with a steel duct 1, in which only part of the concrete segment was shown in the form of a rectangular block.
• Figure 2 is a schematic cross section perspective view showing the vertical assembly process for the segments 10 illustrated in Figure 1.
• Figure 3 is a schematic cross section perspective view showing the assembled segments.
• Figure 4 is a perspective view showing another embodiment of the steel duct 1.
• the present invention aims to provide a method for a facile construction of precast concrete segments 10 equipped with steel ducts 1, capable of producing concrete segments 10 in which the positioning of said steel ducts 1 therein is exactly perpendicular at their designed locations.
• a method for constructing precast concrete segments comprising a cylindrical steel duct comprising the following steps: (a) providing a mold bottom plate equipped with a vertical insertion member fastened to a position at which said steel duct will be located, said vertical insertion member being capable of supporting the insertion of said steel duct in an upright fashion; (b) inserting said vertical insertion member into said steel duct so that the upper part of said vertical insertion member fits inside the lower part of said steel duct; (c) placing reinforcement steel rods for said concrete segment; (d) building mold walls; (e) placing the mold cover; (f) pouring concrete into the space created by said mold bottom plate, mold walls and mold cover; and (g) removing said mold bottom plate, mold walls and mold cover after the concrete is cured, wherein said steel duct is installed with tendons therein to apply tension, and wherein said steel duct, placed within said segment, runs through said segment along the
• said steel duct can be provided thereon with a protrusion which serves as a hanger for steel rods and supports integration of said steel duct into said segment when placed within the concrete making up the said segment, said protrusion being integral with said steel duct, and wherein reinforcement steel rods are placed around said steel duct inside said segment by hanging a steel band on said protrusion.
• the upper part of said vertical insertion member may have the shape of a spigot with a narrowing taper.
• precast concrete segments containing steel ducts can be readily produced in which said steel ducts remain exactly perpendicular to said segment at their designed locations.
• the installation of vertical steel ducts can be readily accomplished in a perpendicular fashion.
• the placement of reinforcement steel rods becomes facilitated since the protrusions from said steel ducts can be used as hangers for steel rods.
• the present invention provides consistency in the sizes and shapes of the segments, leading to a precise and facile assembly of individual segments. [18]
• Figure 1 is a perspective view of a precast concrete segment equipped with a steel duct in which only part of the concrete segment was illustrated in the form of a rectangular block.
• Figure 2 is a schematic cross section perspective view showing the vertical assembly process for the segments illustrated in Figure 1.
• Figure 3 is a schematic cross section perspective view showing the assembled segments according to the embodiment illustrated in Figure 2.
• Figure 4 is a schematic perspective view showing another embodiment of the steel duct.
• Figure 5 shows in a schematic perspective view the first step in the construction of the inventive segments equipped with steel ducts in which a mold bottom plate is installed.
• Figure 6 shows the mold bottom plate of Figure 5 in which steel ducts are placed upright thereon in a schematic perspective view.
• Figure 7 is a perspective view showing another embodiment of the steel duct that is placed within the segments.
• Figure 8 is a perspective view of a mold bottom plate on which steel ducts with protrusions are installed followed by placement of a steel band.
• Figure 9 is a perspective view of a mold after walls are placed.
• Figure 10 is an exploded perspective view of a mold on which a mold cover is placed on top of mold walls following the placement of these walls as shown in Figure 9; the design of the mold cover is such that the installed steel ducts become fastened to their positions.
• Figure 11 is a perspective view showing the mold cover placed on top of the mold.
• Figure 12 is a perspective view of a segment produced according to the method of the present invention.
• Figure 5 shows the first step in the construction of the inventive segments 10 equipped with steel ducts 1 in which a mold bottom plate 20 is installed in a schematic perspective view.
• Figure 6 shows the mold bottom plate 20 of Figure 5 in which steel ducts 1 are vertically placed thereon in a schematic perspective view.
• a mold bottom plate 20 is equipped with a vertical insertion member 21 fastened to a position at which said steel duct 1 will be located, wherein said vertical insertion member 21 is capable of supporting the insertion of said steel duct 1 in a vertical fashion.
• said vertical insertion member 21 is fitted inside said steel duct 1 in such a way that the upper part of said member 21 is inserted into the lower part of said steel duct 1, a vertical placement of said steel duct 1 can be accomplished at its predetermined location as shown in Figure 6.
• the fitting of said steel duct 1 with said member 21 is made easier.
• FIG. 7 another embodiment of said steel duct 1 is shown as a perspective view.
• the steel duct 1 is provided thereon with a protrusion 2 which functions as a hanger for steel rods and supports integration of said steel duct 1 into said segment 10 when placed within the concrete making up the said segment 10.
• said protrusion 2 can be formed by welding bolts or installed by perforating holes on the exterior of said steel duct 1 and attaching bolts inside these holes. There are no limits to the design of these protrusions 2 as well as methods of their production.
• said protrusions 2 function as hangers for steel rods.
• Figure 8 a perspective view of a mold bottom plate 20 is given wherein steel ducts 1 containing said protrusions 2 have been installed thereon followed by a placement of a steel band.
• reinforcement steel rods can be readily placed around said steel ducts 1 by hanging steel bands 3 on said protrusions 2.
• Figure 8 illustrates the case using only 2 steel bands 3; however, spacing between each protrusion 2 and the number of steel bands 3 are subject to change depending on the specific design.
• vertical steel rods and reinforcement steel rods for other applications may be added as well.
• Figure 9 is a perspective view of a mold with its walls 22 installed. Part of the two walls in the front has been omitted for clarity in Figure 9.
• the working order may as well be switched so that the mold bottom plate 20 and mold walls 22 are installed first and said steel duct 1 is set up later by inserting the vertical insertion member 21 thereto.
• Figure 10 is an exploded perspective view of a mold on which a mold cover 23 is placed on top of mold walls 22 following the placement of these walls as shown in Figure 9; the design of the mold cover 23 is such that the installed steel ducts 1 become fastened to their positions.
• Figure 11 is a perspective view showing the mold cover 23 placed on top of the mold. In Figures 10 and 11, part of the two front walls has been omitted for clarity so as to reveal the interior of the mold.
• said mold cover 23 has installation holes 24 for the upper part of said steel duct 1 at matching positions for locating said steel ducts 1 to their predetermined positions. Accordingly, the upper part of said steel duct 1 is inserted into said installation hole 24 so that the inserted steel duct 1 is able to maintain an upright, perpendicular posture once said mold cover 23 is placed. At this stage, the depth to which said steel duct 1 must be inserted into said installation hole 24 is one that allows the upper part of said steel duct 1, in particular the upper part of a steel duct 1 with a spigot such as shown in the drawings, to jut out from the segment 10.
• Figure 12 illustrates a perspective view of a segment 10 produced according to such method.
• said steel duct 1 can be made from various other materials besides steel as long as they have the necessary strength or physical properties for replacing said steel duct 1.
• One example would be synthetic resins such as high strength plastic.
• vertical insertion members are installed on a mold bottom plate and steel ducts are then fastened onto said plate by fitting with the installed members before concrete is poured.
• Such arrangement allows construction of concrete segments while said steel ducts are kept in a perpendicular posture at their predetermined locations.
• placing said steel ducts in an upright, perpendicular posture, as mentioned above, can be made much easier by inserting the upper part of said steel duct into said installation hole.
• the present invention has the advantage that it can easily produce concrete segments in which the installed steel ducts are kept exactly perpendicular to said concrete segment at their designed locations.
• the present invention enables a precise control of sizes and shapes in the construction of these concrete segments, one can achieve consistency in the sizes and shapes of the segments produced, leading to a precise and facile assembly of individual segments.
• this inventive method is applied to the assembly of precast pier segments, enhanced constructability can be achieved in the construction of piers of various heights since the specifics of design such as segment heights can be freely adjusted if necessary.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Ceramic Engineering (AREA)
• Mechanical Engineering (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Bridges Or Land Bridges (AREA)
• Lining And Supports For Tunnels (AREA)
• Moulds, Cores, Or Mandrels (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

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Cited By (1)

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Citations (5)

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• 2006
  • 2006-07-10 KR KR1020060064292A patent/KR100776774B1/ko not_active IP Right Cessation
• 2007
  • 2007-06-15 WO PCT/KR2007/002907 patent/WO2008007863A1/en active Application Filing
  • 2007-06-15 CN CN2007800012401A patent/CN101356317B/zh not_active Expired - Fee Related

Patent Citations (5)

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