This document describes the construction process and technology used to cast concrete beams for Do Vang Bridge on scaffolding. Key steps include:
1) Constructing steel scaffolding and formworks to support the casting of each concrete beam segment.
2) Installing reinforcement cages, ducts for prestressing cables, and bearings before pouring concrete.
3) Segmentally constructing each beam by casting concrete sections supported by scaffolding, then moving the scaffolding to begin the next section.
Formwork for Bridge and Centering Of ArchYash Patel
This document discusses different types of formwork and centering used in bridge construction. It describes centering for arches, including factors to consider like arch shape, span and thickness. Big arches may use timber truss, trestle or steel truss centering. Falsework supports arch structures during construction and consists of foundation pads, corbels, beams and posts. Slip formwork is an economical system for vertical structures like piers using sheathing, wales, yokes and scaffolds that eliminates joints and allows speedy construction.
Formwork is a temporary structure used to contain wet concrete until it is cured sufficiently to stand on its own. It supports the concrete and maintains its shape. Common materials used are timber, plywood and steel. Formwork must be strong, rigid, braced and water tight. It supports live and dead loads and maintains shape during construction. Formwork is designed based on the type and location of concrete element being cast. Proper formwork design and construction is important for safety and to produce high quality concrete surfaces.
Formwork is a temporary mold used to contain poured concrete until it cures and can support itself. It needs to be strong enough to support the weight of wet concrete and withstand pouring and compaction loads. New materials like steel and plastics are now used for formwork in addition to wood. Slipforming allows for continuous vertical pouring of concrete structures like building cores without relying on external support, by using a formwork that rises slowly on its own as concrete is added.
Form work for R.C.C. Wall, slab, beam and column, centering for arches
of large spans and dams, design features for temporary works, slip
formwork, False work for Bridges
Here is the table explaining the types of materials available for formwork:
Material | Suitability | Advantages | Disadvantages | Cost
-|-|-|-|-
Timber | Suitable for all types of formwork including beams, columns, slabs and foundations. Commonly used material. | Readily available. Easy to work with using basic carpentry tools. Can be reused multiple times if properly maintained. | Requires more maintenance between uses. Subject to damage. Absorbs water reducing quality of concrete surface. More combustible. | Low cost.
Plywood | Suitable for slab formwork and walls. | Strong and durable. Provides smooth concrete finish. Water resistant. | Heavier than timber. Requires proper support
A study on the construction process (Precast concrete, In-situ cast concrete,...Bhaddin Al-Naqshabandi
This document provides an overview of precast concrete construction, in-situ cast concrete construction, shoring, and underpinning. It describes that precast concrete elements are cast off-site and include items like slabs, beams, and wall panels. In-situ concrete is poured on-site and can form any shape but requires more time and resources. Shoring uses temporary structures like rakers to support unstable structures during construction. Underpinning strengthens existing foundations, for example by adding new piles or walls underneath for additional support.
Prefabrication & Pre-CASTING, Advanced Structural Concretes Materials for Pre...Deepak Verma
This document discusses modular and prefabricated construction components used in precast concrete buildings. It describes the key components that can be prefabricated off-site such as walls, floors, beams, columns, stairs, and their connections. These include different types of precast walls, slabs, beams shaped as I-beams, L-beams or rectangular, and dimensions for efficient construction. Connection details are provided for beam-column, wall-foundation, and other joints.
Formwork for Bridge and Centering Of ArchYash Patel
This document discusses different types of formwork and centering used in bridge construction. It describes centering for arches, including factors to consider like arch shape, span and thickness. Big arches may use timber truss, trestle or steel truss centering. Falsework supports arch structures during construction and consists of foundation pads, corbels, beams and posts. Slip formwork is an economical system for vertical structures like piers using sheathing, wales, yokes and scaffolds that eliminates joints and allows speedy construction.
Formwork is a temporary structure used to contain wet concrete until it is cured sufficiently to stand on its own. It supports the concrete and maintains its shape. Common materials used are timber, plywood and steel. Formwork must be strong, rigid, braced and water tight. It supports live and dead loads and maintains shape during construction. Formwork is designed based on the type and location of concrete element being cast. Proper formwork design and construction is important for safety and to produce high quality concrete surfaces.
Formwork is a temporary mold used to contain poured concrete until it cures and can support itself. It needs to be strong enough to support the weight of wet concrete and withstand pouring and compaction loads. New materials like steel and plastics are now used for formwork in addition to wood. Slipforming allows for continuous vertical pouring of concrete structures like building cores without relying on external support, by using a formwork that rises slowly on its own as concrete is added.
Form work for R.C.C. Wall, slab, beam and column, centering for arches
of large spans and dams, design features for temporary works, slip
formwork, False work for Bridges
Here is the table explaining the types of materials available for formwork:
Material | Suitability | Advantages | Disadvantages | Cost
-|-|-|-|-
Timber | Suitable for all types of formwork including beams, columns, slabs and foundations. Commonly used material. | Readily available. Easy to work with using basic carpentry tools. Can be reused multiple times if properly maintained. | Requires more maintenance between uses. Subject to damage. Absorbs water reducing quality of concrete surface. More combustible. | Low cost.
Plywood | Suitable for slab formwork and walls. | Strong and durable. Provides smooth concrete finish. Water resistant. | Heavier than timber. Requires proper support
A study on the construction process (Precast concrete, In-situ cast concrete,...Bhaddin Al-Naqshabandi
This document provides an overview of precast concrete construction, in-situ cast concrete construction, shoring, and underpinning. It describes that precast concrete elements are cast off-site and include items like slabs, beams, and wall panels. In-situ concrete is poured on-site and can form any shape but requires more time and resources. Shoring uses temporary structures like rakers to support unstable structures during construction. Underpinning strengthens existing foundations, for example by adding new piles or walls underneath for additional support.
Prefabrication & Pre-CASTING, Advanced Structural Concretes Materials for Pre...Deepak Verma
This document discusses modular and prefabricated construction components used in precast concrete buildings. It describes the key components that can be prefabricated off-site such as walls, floors, beams, columns, stairs, and their connections. These include different types of precast walls, slabs, beams shaped as I-beams, L-beams or rectangular, and dimensions for efficient construction. Connection details are provided for beam-column, wall-foundation, and other joints.
Formwork is used to shape and support concrete until it gains strength. It can be made from various materials like timber, plywood, steel, aluminum, and plastics. Timber was traditionally most common but other materials are increasingly used. Different types of formwork exist for walls, slabs, columns, etc. Proper formwork construction involves propping, shuttering, providing chambers, cleaning, and surface treatment. Formwork must be removed carefully in the proper sequence once the concrete has gained enough strength. The type of material used depends on factors like cost, availability, and need for reuse.
A presentation with exhaustive information about the general idea of formwork, the various types, the newest introductions and a comparative study between the conventional and modern-day formwork.
It also includes the study of causes of failure of formwork and the safety measures to be taken for preventing failure.
Form work_Advanced Construction Technology (Semester-6), Civil EngineeringA Makwana
The form work is a temporary ancillary construction used as a mould for the structure, in which concrete is placed and in which it hardens and matures.
Cost of form work- 20 to 25 % of the cost of structure in building work
The document outlines the typical steps involved in a construction project, including site clearance, leveling, center line marking, excavation, PCC work, footing, SSM work, plinth beam and slab, erection of columns, BBM, erection of doors and windows, lintel and chejja, roofing, parapet, concealing, plastering, flooring and final finishing. It also provides details on specific construction activities like excavation, PCC work, footing, SSM work, plinth beam and slab construction, erection of columns, BBM, erection of doors and windows, lintel and chejja, roofing, parapet, concealing, plastering and ready
Speedy construction methods aim to shorten construction timelines through faster curing of concrete elements and optimized formwork. Cast-in-situ concrete involves pouring concrete on-site but takes longer to cure, while precast concrete is cast off-site and lifted into place, shortening construction times. Composite construction combines concrete and steel elements to utilize the strengths of each material. Different slab systems like solid slabs, ribbed slabs, and waffle slabs provide options to span varying distances based on structural needs and optimize material usage.
This document discusses precast concrete construction. Some key points:
- Precast concrete elements are cast and cured off-site then transported for assembly, allowing more efficient production and quality control.
- Elements include slabs, beams, columns, and wall panels that are joined on-site through embedded bolts, plates, and grouted connections.
- The precasting process involves casting concrete around prestressing strands to add strength, then cutting sections and transporting them for erection.
The document discusses underpinning, which is strengthening and stabilizing an existing building's foundation. Reasons for underpinning include an insufficient original foundation, changed building usage or soil properties, or nearby construction requiring soil excavation. Underpinning extends the foundation deeper or wider to bear on stronger soil or distribute load. Common methods are micropiles, jet grouting, and soil grouting. Types of underpinning include mass concrete, beam and base, and mini-piled underpinning. Mass concrete involves digging boxes and pouring concrete sequentially. Beam and base uses a reinforced concrete beam supported by mass concrete bases. Mini-piles are used for deep foundations on variable soils.
This document provides information on formwork used for constructing concrete structures. It discusses the different types of formwork including wooden, plywood, steel and combined forms. It also describes requirements for proper formwork like being waterproof and strong enough to support loads. Common formwork systems are described for columns, beams, slabs, stairs and walls. Standards for stripping formwork from concrete structures are also outlined according to the Indian Standard code.
Formwork refers to the temporary structure used to support wet concrete until it is cured. There are different types of formwork including wood and steel. Wood formwork uses props, planks, battens and sheeting while steel uses sheets, angles and tees. Formwork must be strong, waterproof, and allow concrete to harden to the required strength before removal. The timing of removal depends on concrete mix design and weather conditions. Formwork is an important part of concrete construction and can account for 20-60% of the total concrete cost.
A truss is a structure composed of straight members arranged in a triangular pattern and connected at their ends to form a rigid framework. Trusses are commonly used in buildings to support roofs and floors over long spans. They provide strength and support loads using less material than beams. Common types of trusses include Pratt trusses and lattice girders, which are used to support trusses running perpendicular. Trusses are fabricated from rolled steel sections or built-up sections and connected by bolting, welding, or riveting. They are an economical choice for supporting large loads and spans in industrial and commercial buildings.
The document discusses different types of reinforcement used in concrete construction including hot rolled deformed bars, mild steel plain bars, cold worked steel reinforcement, and prestressing steel. It also discusses ready mixed concrete (RMX), the working process of RMX, advantages and disadvantages compared to site mixed concrete. The document provides information on major RMX companies. It also discusses insulating concrete formwork (ICF), crosswall construction formwork, and photos of ICF site installation.
This document defines formwork and its requirements, categories, types of materials used, and construction process. Formwork is a temporary mold into which concrete is poured and shaped. It must be strong enough to support the weight of wet concrete and loads. There are traditional, engineered, and modern modular types. Common materials are timber, steel, plastic, and aluminum. Proper construction and removal of formwork is important for quality, safety, and economy of concrete structures.
Formwork is a temporary structure used to support wet concrete until it cures and can support itself. There are different types of formwork materials including timber, steel, and glass reinforced plastic. Proper formwork design and construction helps ensure safety, cost-effectiveness and quality of the finished concrete surface. Common causes of formwork failure include inadequate bracing, vibration, unstable soil or improper stripping. Safety precautions like secure fixing and inspections are important to prevent accidents. Permanent formwork is part of the permanent structure and remains in place for the life of the building, offering advantages like reduced construction time and costs.
This document provides information about DOKA table formwork system. It summarizes that the DOKA system uses preassembled modular forms to create suspended concrete floors quickly and with mobility. The forms are made of linked beams, props, and trusses that can be fitted with wheels and moved easily. The document outlines design considerations for the forms including supporting loads, materials used, safety features, and advantages like fast construction, quality finishes, and reusability.
It is the presentation based on precast concrete construction which includes each and every point and scope which may be useful to civil engineering students
This document discusses reinforced concrete and its properties. It explains that concrete is weaker in tension than compression, while steel has high tensile strength and bonds well with concrete. When combined, they form reinforced concrete which is strong and durable. The steel carries tensile forces while the concrete resists compression. Proper placement of reinforcement during construction is important for bond. Methods of bending, tying, and installing rebar are also outlined.
Running Head BRIDGE DESIGN1BRIDGE DESIGN31.docxtoddr4
Running Head: BRIDGE DESIGN 1
BRIDGE DESIGN 31
Title:
Student Name:
Institution:
Course:
Date:
BRIDGE DESIGN FOR THE MOTOR WAY BELOW
8m
Embankment
A
Motorway
16m
10m
Central Reservation
Motorway
16m
Grass Verge
Existing Factory Units
Footway
A
Carriagewaym
Existing Factory Units
Fixed Factory Entrance
Fixed Factory Entrance
3m
2m
3m
2m
10mm
Existing Highway to Proposed Bridge
Existing Development
Proposed Development
Existing Development
Existing Retaining Wall – 500mm thick rc construction indicated by old record drawings
Central Reservation
10m
10m
Section A-A
2m footway
1.2m high parapets
10m carriageway
Bridge Deck Section
Figure 1
Bridge design
Most suitable bridge forms
· Beam bridge
· Arch bridge
The beam bridge: Beam and slab with ladder decks
This form of bridges comprises of slab which sits on top of steel I-beams. This form is mostly used for mid span highway bridge which is where our required bridge falls in.
Slab in this system is supported on tow main girders with a spacing of about 3.5m and it lies longitudinally between the girders as per the below diagram.
Figure 1
The bridge will use plate girders giving us a scope to vary the flange and web sizes to fit and suit the bridge load carrying capabilities. In the design process, ability of the bridge to carry the maximum load expected and the loading at the various stages of construction will guide on the proportion of girders that is their depth, width of tension and compression flanges and web thickness.
The girders are erected firmly on the ground and have stud connectors welded on the top flange to provide composite action between the slab and girder. The number of studs and spacing vary depending on expected level of shear flow between steel girder and concrete slab.
The girders rest on bearings fastened to the bottom flange. The girders are stiffened to carry the bearing loads at these points. Some cases apply bracing between the girders at support to carry lateral forces and provide torsional restraint.
Bridge description
· The bridge will have a span of 50m.
· The bridge will be raised to a height of 10m on both sides to be in level with the existing highway. The girders will have constant height.
· The bridge cross section will have the reinforced concrete slab sitting on top of two main abutment substructures and an extra substructure which will be on the central reservation. The main substructure will be located at the embarkment of the road.
Construction sequence
Abutment substructure construction
Girder construction
The bridge will consist of two main girder I beams. The girders will be of the same height. To make the I-beam, steel plates will be used. The steel plate is cut into the required sizes for the bottom flange and top flange and for the web. The cut pieces are then fillet welded into the I-section. This is done either by machine manual assembling in jig or through improved pressing machine .
This document provides a summary of the walkway construction project from 2014-2016 for CTCI Singapore & CTCI Corporation Consortium. It describes the organization structure, components and methods of construction. Key aspects included base infill, support unit casting, cable trough installation, ramp construction, and handover requirements. Construction efficiency, manpower, tools/equipment, drawings and conclusions/lessons learned are also summarized. Proper planning and coordination between teams was important to the successful and timely completion of the 28km of walkway construction.
Formwork is used to shape and support concrete until it gains strength. It can be made from various materials like timber, plywood, steel, aluminum, and plastics. Timber was traditionally most common but other materials are increasingly used. Different types of formwork exist for walls, slabs, columns, etc. Proper formwork construction involves propping, shuttering, providing chambers, cleaning, and surface treatment. Formwork must be removed carefully in the proper sequence once the concrete has gained enough strength. The type of material used depends on factors like cost, availability, and need for reuse.
A presentation with exhaustive information about the general idea of formwork, the various types, the newest introductions and a comparative study between the conventional and modern-day formwork.
It also includes the study of causes of failure of formwork and the safety measures to be taken for preventing failure.
Form work_Advanced Construction Technology (Semester-6), Civil EngineeringA Makwana
The form work is a temporary ancillary construction used as a mould for the structure, in which concrete is placed and in which it hardens and matures.
Cost of form work- 20 to 25 % of the cost of structure in building work
The document outlines the typical steps involved in a construction project, including site clearance, leveling, center line marking, excavation, PCC work, footing, SSM work, plinth beam and slab, erection of columns, BBM, erection of doors and windows, lintel and chejja, roofing, parapet, concealing, plastering, flooring and final finishing. It also provides details on specific construction activities like excavation, PCC work, footing, SSM work, plinth beam and slab construction, erection of columns, BBM, erection of doors and windows, lintel and chejja, roofing, parapet, concealing, plastering and ready
Speedy construction methods aim to shorten construction timelines through faster curing of concrete elements and optimized formwork. Cast-in-situ concrete involves pouring concrete on-site but takes longer to cure, while precast concrete is cast off-site and lifted into place, shortening construction times. Composite construction combines concrete and steel elements to utilize the strengths of each material. Different slab systems like solid slabs, ribbed slabs, and waffle slabs provide options to span varying distances based on structural needs and optimize material usage.
This document discusses precast concrete construction. Some key points:
- Precast concrete elements are cast and cured off-site then transported for assembly, allowing more efficient production and quality control.
- Elements include slabs, beams, columns, and wall panels that are joined on-site through embedded bolts, plates, and grouted connections.
- The precasting process involves casting concrete around prestressing strands to add strength, then cutting sections and transporting them for erection.
The document discusses underpinning, which is strengthening and stabilizing an existing building's foundation. Reasons for underpinning include an insufficient original foundation, changed building usage or soil properties, or nearby construction requiring soil excavation. Underpinning extends the foundation deeper or wider to bear on stronger soil or distribute load. Common methods are micropiles, jet grouting, and soil grouting. Types of underpinning include mass concrete, beam and base, and mini-piled underpinning. Mass concrete involves digging boxes and pouring concrete sequentially. Beam and base uses a reinforced concrete beam supported by mass concrete bases. Mini-piles are used for deep foundations on variable soils.
This document provides information on formwork used for constructing concrete structures. It discusses the different types of formwork including wooden, plywood, steel and combined forms. It also describes requirements for proper formwork like being waterproof and strong enough to support loads. Common formwork systems are described for columns, beams, slabs, stairs and walls. Standards for stripping formwork from concrete structures are also outlined according to the Indian Standard code.
Formwork refers to the temporary structure used to support wet concrete until it is cured. There are different types of formwork including wood and steel. Wood formwork uses props, planks, battens and sheeting while steel uses sheets, angles and tees. Formwork must be strong, waterproof, and allow concrete to harden to the required strength before removal. The timing of removal depends on concrete mix design and weather conditions. Formwork is an important part of concrete construction and can account for 20-60% of the total concrete cost.
A truss is a structure composed of straight members arranged in a triangular pattern and connected at their ends to form a rigid framework. Trusses are commonly used in buildings to support roofs and floors over long spans. They provide strength and support loads using less material than beams. Common types of trusses include Pratt trusses and lattice girders, which are used to support trusses running perpendicular. Trusses are fabricated from rolled steel sections or built-up sections and connected by bolting, welding, or riveting. They are an economical choice for supporting large loads and spans in industrial and commercial buildings.
The document discusses different types of reinforcement used in concrete construction including hot rolled deformed bars, mild steel plain bars, cold worked steel reinforcement, and prestressing steel. It also discusses ready mixed concrete (RMX), the working process of RMX, advantages and disadvantages compared to site mixed concrete. The document provides information on major RMX companies. It also discusses insulating concrete formwork (ICF), crosswall construction formwork, and photos of ICF site installation.
This document defines formwork and its requirements, categories, types of materials used, and construction process. Formwork is a temporary mold into which concrete is poured and shaped. It must be strong enough to support the weight of wet concrete and loads. There are traditional, engineered, and modern modular types. Common materials are timber, steel, plastic, and aluminum. Proper construction and removal of formwork is important for quality, safety, and economy of concrete structures.
Formwork is a temporary structure used to support wet concrete until it cures and can support itself. There are different types of formwork materials including timber, steel, and glass reinforced plastic. Proper formwork design and construction helps ensure safety, cost-effectiveness and quality of the finished concrete surface. Common causes of formwork failure include inadequate bracing, vibration, unstable soil or improper stripping. Safety precautions like secure fixing and inspections are important to prevent accidents. Permanent formwork is part of the permanent structure and remains in place for the life of the building, offering advantages like reduced construction time and costs.
This document provides information about DOKA table formwork system. It summarizes that the DOKA system uses preassembled modular forms to create suspended concrete floors quickly and with mobility. The forms are made of linked beams, props, and trusses that can be fitted with wheels and moved easily. The document outlines design considerations for the forms including supporting loads, materials used, safety features, and advantages like fast construction, quality finishes, and reusability.
It is the presentation based on precast concrete construction which includes each and every point and scope which may be useful to civil engineering students
This document discusses reinforced concrete and its properties. It explains that concrete is weaker in tension than compression, while steel has high tensile strength and bonds well with concrete. When combined, they form reinforced concrete which is strong and durable. The steel carries tensile forces while the concrete resists compression. Proper placement of reinforcement during construction is important for bond. Methods of bending, tying, and installing rebar are also outlined.
Running Head BRIDGE DESIGN1BRIDGE DESIGN31.docxtoddr4
Running Head: BRIDGE DESIGN 1
BRIDGE DESIGN 31
Title:
Student Name:
Institution:
Course:
Date:
BRIDGE DESIGN FOR THE MOTOR WAY BELOW
8m
Embankment
A
Motorway
16m
10m
Central Reservation
Motorway
16m
Grass Verge
Existing Factory Units
Footway
A
Carriagewaym
Existing Factory Units
Fixed Factory Entrance
Fixed Factory Entrance
3m
2m
3m
2m
10mm
Existing Highway to Proposed Bridge
Existing Development
Proposed Development
Existing Development
Existing Retaining Wall – 500mm thick rc construction indicated by old record drawings
Central Reservation
10m
10m
Section A-A
2m footway
1.2m high parapets
10m carriageway
Bridge Deck Section
Figure 1
Bridge design
Most suitable bridge forms
· Beam bridge
· Arch bridge
The beam bridge: Beam and slab with ladder decks
This form of bridges comprises of slab which sits on top of steel I-beams. This form is mostly used for mid span highway bridge which is where our required bridge falls in.
Slab in this system is supported on tow main girders with a spacing of about 3.5m and it lies longitudinally between the girders as per the below diagram.
Figure 1
The bridge will use plate girders giving us a scope to vary the flange and web sizes to fit and suit the bridge load carrying capabilities. In the design process, ability of the bridge to carry the maximum load expected and the loading at the various stages of construction will guide on the proportion of girders that is their depth, width of tension and compression flanges and web thickness.
The girders are erected firmly on the ground and have stud connectors welded on the top flange to provide composite action between the slab and girder. The number of studs and spacing vary depending on expected level of shear flow between steel girder and concrete slab.
The girders rest on bearings fastened to the bottom flange. The girders are stiffened to carry the bearing loads at these points. Some cases apply bracing between the girders at support to carry lateral forces and provide torsional restraint.
Bridge description
· The bridge will have a span of 50m.
· The bridge will be raised to a height of 10m on both sides to be in level with the existing highway. The girders will have constant height.
· The bridge cross section will have the reinforced concrete slab sitting on top of two main abutment substructures and an extra substructure which will be on the central reservation. The main substructure will be located at the embarkment of the road.
Construction sequence
Abutment substructure construction
Girder construction
The bridge will consist of two main girder I beams. The girders will be of the same height. To make the I-beam, steel plates will be used. The steel plate is cut into the required sizes for the bottom flange and top flange and for the web. The cut pieces are then fillet welded into the I-section. This is done either by machine manual assembling in jig or through improved pressing machine .
This document provides a summary of the walkway construction project from 2014-2016 for CTCI Singapore & CTCI Corporation Consortium. It describes the organization structure, components and methods of construction. Key aspects included base infill, support unit casting, cable trough installation, ramp construction, and handover requirements. Construction efficiency, manpower, tools/equipment, drawings and conclusions/lessons learned are also summarized. Proper planning and coordination between teams was important to the successful and timely completion of the 28km of walkway construction.
Internship project Report Gammon India pvt. ltd.SHWETABH SINHA
This document provides an overview of the construction of an elevated road corridor from AIIMS to Digha in Patna, Bihar, India. The 11.9 km project involves constructing a 2-lane semi-elevated structure and an 8.5 km 4-lane elevated structure. It will include bridges, culverts, intersections and other infrastructure. The project is being executed using an EPC model and will help reduce traffic congestion and travel times in the area once completed.
This document outlines the method statement for concrete work and formwork for the construction of buildings at Cai Mep International Container Terminal. It details the procedures for rebar work, formwork installation, concrete casting, curing, and formwork removal. The scope of work includes construction of a security office, amenity block, container freight station, and container gate using reinforced concrete and steel structures. Diagrams in the appendix illustrate the casting concrete and formwork installation methods. Safety controls and compliance with technical specifications and drawings are also addressed.
ADTO Ringlock System introduction and projects listColin Cai
The document introduces the ADTO Ringlock scaffolding system and provides details on its parts and certificates. It then summarizes several construction projects where the ADTO Ringlock system was used, including details on the project location, contractor, structure height, and how the system was configured for different load requirements. Contact information is provided to obtain more information from Mr. Colin.
This document discusses prefabricated concrete columns. It defines prefabrication as assembling building components in a factory and transporting them to the construction site. Precast concrete columns can be single or double-story height and are made in modular designs to accommodate different heights. Columns have widths of 300mm, 450mm, or 600mm and can be rectangular or circular. Connection methods between the column and foundation include cast-in base plates, dowel tubes, or projections. The manufacturing process for precast concrete components involves 10 main steps including installing molds and reinforcement, pouring and vibrating concrete, curing, and removing molds.
The document discusses various techniques used for formwork in high-rise construction, including slip forming, jump forming, climbing forming, tunnel forming, and table forming. It provides details on slip forming where concrete is continuously poured into a moving form. Jump forming uses movable platforms to construct shear walls and cores more quickly. Tunnel forming constructs horizontal and vertical elements together for efficient construction. The document also discusses various commercial formwork systems used, such as Doka, Coffor, PERI, and Mivan, outlining their components, applications, advantages, and limitations.
This document provides details on the construction process for the substructure of a bridge, including pile foundations and a pile cap. It describes the steps to construct cast-in-place concrete piles, which include boring holes for the piles, lowering reinforced steel cages into the holes, fitting tremie pipes to pour concrete, and flushing out debris. It also outlines the process for constructing the pile cap, such as excavating around the piles, chipping off excess concrete, forming shutters, placing reinforcing steel, and pouring concrete. The overall bridge construction process is divided into substructure and superstructure work.
The main outcome of this project is the construction sequence of HMR which primarily starts with excavation, erection of piers, launching girder process and assembling of segments. This project clearly gives a brief knowledge on how the post tensioning and pre stressing works are held at off site and onsite. This project enlightens about the safety requirements and measures taken during the pre-casting works and at on site works.
This document provides details on the construction sequence and industrialized building system components for a 3 storey apartment building. It begins with an introduction to the building design which utilizes precast concrete and prefabricated timber framing. Section 2 describes the precast concrete and prefabricated timber systems to be used, including details on the fabrication process and types of components. Section 3 outlines the 14 step construction sequence. Section 4-6 provide drawings and details of the modular building components and construction.
The document provides information on the construction and erection of bridge elements such as prestressed concrete girders and deck slabs. It discusses casting of bridge girders using steel molds, various launching methods for erecting girders including using launching girders, and the balanced cantilever method of construction where bridge segments are constructed in a balanced manner from each pier until the two halves are joined. It also covers different types of bridge decks and systems used for structural steel girder bridges.
Bored cast in situ piles are constructed by digging a hole in the ground using percussive or rotary methods with temporary or permanent casing. Reinforcing bars are placed in the hole and concrete is poured in, filling the hole. The process involves accurately setting out pile points, stabilizing the borehole with bentonite, placing reinforcement cages without disturbing the borehole, and concreting from the bottom up using a tremie pipe to prevent mixing of concrete and bentonite. Bored cast in situ piles are well-suited for applications requiring noise prevention during construction, socketing into rock, or high load-bearing capacity piles.
Ques: 1.Why this system is called SLIPFORMING?
Ques: 3.Slipforming is mechanized way of constructing very high structures & involves Mechanical/Civil/Hydraulic Engineers. Explain?
Ques: 4.How the tapering structures are made by Slipforming? How do we reduce
diameter, wall thickness & do Lifting Simultaneously?
Ques: 5.Manpower saving in Slipforming (no carpenters required), Good for the
Country/Employment?
Ques: 6.Will mechanization in form work render our carpenters idle?
Ques: 7.Scaffolding is major capital investment in Construction Projects, no
scaffolding is required for Slipform Projects, and how Slipforming is cost effective?Please discuss.
The document discusses precast concrete structural elements used in construction. It describes four types of precast concrete slabs (solid, hollow-core, double tees, and single tees) that are commonly used as floor and roof elements. It also discusses precast concrete beams, girders, columns, and wall panels. Finally, it outlines the assembly concepts and construction process for buildings made with precast concrete elements.
The document discusses the design and construction of a 4-lane 90m railway over bridge in Chand Sarai, Lucknow. Key steps in the construction process include surveying, engineering design, laying pile foundations, installing bearings and girders, shuttering, and concreting. Tests were conducted on materials and foundations to ensure quality. The bridge was designed to allow road traffic to safely pass over the railway line.
The document provides details on the use of industrialized building systems for a building project. It includes an introduction to IBS and precedent studies. It then describes the various IBS components to be used, including precast concrete columns, beams, slabs, and stairs. Prefabricated steel will be used for toilet pods and the roof structure. Fabrication and installation processes are outlined for the different components.
This document summarizes the process for constructing secant piles for a microtunnel shaft. It involves first constructing guide walls as reference points. Then female piles are drilled and concreted without reinforcement cages using lower grade concrete. Male piles are drilled between female piles, cutting through them. Reinforcement cages are installed in male piles before higher grade concrete is placed continuously from the bottom up via a tremie. The casing is gradually extracted to allow the concrete to rise above the cutoff level.
Guidelines on technical_specifications_for_the_installation_of_telecommunicat...Patrice Adjei
This document provides guidelines for the installation of telecommunications masts and towers in Nigeria. It covers various types of towers including monopole, guyed, self-supporting and roof mounts. Design considerations like tapering, bracing and painting are specified. Guidelines are provided for siting towers with respect to setbacks, lighting and environmental factors. Construction details cover foundations, substructures and safety. Specifications are given for materials, joints, climbing apparatus and maintenance. Applications for permits and certifications are also outlined. The document aims to ensure safety, sound engineering practices and compliance with international standards.
The document outlines the construction sequence for building a diaphragm wall. It involves:
1. Constructing guide walls along the perimeter to stabilize the soil and provide a guide for excavation.
2. Boring the diaphragm wall sections using a hydraulic grab in sequential sections. Polymer slurry is used to retain the soil.
3. Fabricating and installing the reinforced concrete cage by cutting, bending and fixing steel reinforcement, then lowering the cage into the excavated sections.
4. Concreting the diaphragm wall sections using a tremie pipe to fill from the bottom up to form a continuous wall. Anchors are then installed and stressed.
2016-03-17 Velocity 2_Construction of Steel DomeWAIKIT CHEOR
This document summarizes the construction of a steel dome at a mall located near the intersection of Jalan Cheras and Jalan Peel. The original design was redesigned to be less complex, lighter weight, and lower cost. Key steps included designing, procuring materials, fabricating steel members, installing reinforced concrete supports, and installing the dome pieces from July to August 2015. Challenges included installing without scaffolding from the 6th floor up, difficult access, and precise installation of the 5-tonne upper dome piece. Lessons learned included improving designs through value engineering for better construction.
This document discusses guidelines for ensuring worker safety during three phases of bridge construction:
1. Erecting and removing scaffolding, emphasizing proper equipment, supervision, and fall protection.
2. Concrete pouring, focusing on pump equipment safety and limits.
3. Prestress cable installation, requiring signal barriers and safe positioning during tensioning.
The appendix specifies allowable errors in bridge component dimensions.
The document discusses material requirements and regulations for the Hanoi-Hochiminh City railway line bridges safety improvement project. It specifies requirements for reinforcement, prestressed anchors, ducts, and concrete materials including cement, aggregates, water, and admixtures. Reinforcement must meet various strength and composition standards. Concrete mix design must conform to project specifications, and materials must meet standards for content, storage, and quality control testing.
The document describes the Do Vang bridge, which is part of a railway line bridges safety improvement project in Vietnam. The Do Vang bridge crosses the Rao Nay River and has 4 prestressed concrete spans and 2 steel truss spans, for a total length of 230.4 meters. The natural conditions of the bridge construction area include hilly terrain, seasonal rainfall and winds, and geological layers consisting of poorly plastic clay and weathered granite. The project scope involves designing and constructing the bridge using reinforced concrete, prestressed concrete, and steel trusses according to applicable Vietnamese standards.
This document outlines the construction technology and process for casting bridge beams on scaffolding as part of the Hanoi-Hochiminh City railway line bridges safety improvement project. It describes the natural conditions of the construction area and covers 4 chapters that explain the construction sequences, technology steps including erecting scaffolding, installing formwork and reinforcement, casting and curing concrete, tensioning prestressed cables, grouting ducts, and removing scaffolding. It also includes regulations on construction materials and safety measures for workers during different phases of construction.
1. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
CHAPTER II: TECHNOLOGY PROCESS
I. CONSTRUCTION SEQUENCES
Concrete beams of Do Vang Bridge are casted in place on the scaffolding.
Construction scaffoldings are made up of shape steel including of: longitudinal beam
H200 and horizontal beam and scaffolding system for supporting side formworks.
Side formworks, bottom formworks, internal formworks with splint system, through
bar must be stably, firmly throughout concreting process.
After completion span 2 and span 5, formwork scaffolding will be transferred to
construct the next spans.
Concrete shall be provided from batching plan at Site with capacity 60m 3/h to the
constructed position by truck mixer and concrete pump.
• Construction sequences
+ Step 1: Land levelling at position of girder construction, filling sand and
compacting to K95. Installing the concrete plank 1x1x0.2m.
+ Step 2: Installing the scafolding, longitudinal beam H200 and horizontal beam
H200
+ Step 3: Testing of scaffold.
+ Step 4: Install external formwork, side formwork
+ Step 5: Install reinforcing steel, pouring concrete
+ Step 6: Stretch prestressed cable.
+ Step 7: Removal of scaffolding, internal formwork, pushing scaffolding
system.
+ Step 8: Connect projecting reinforcement couplers of diagraphm,
reinforcement, diaphragm formwork. Placing concrete and stressing horizontally
prestressed cable of diaphragm.
+ Step 9: Construction of the next span.
II. TECHNOLOGY STEPS
1. Land levelling
Land levelling at position of girder construction, filling sand and compacting to K95.
Installing the concrete plank 1.2x1.2x0.18m2. Production and erection of scaffolding
Scaffolding, formwork must be designed to resist any unfavouble displacement during
superstructure construction process.
Construction scaffolding is included:
+ Supporting scaffolding of side formwork
+ Installing the scafolding, longitudinal beam H200 and horizontal beam H200
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2. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
Figure 1: Span structure’s construction scaffolding
3. Testing scaffolding
This test aims to remove the settlement of scaffolding system, check the pressure
bearing ability of scaffolding. Load test results must be reported immediately to The
Engineer.
4. Install beam formwork
• Concreting formwork design
+ Bottom formwork is combined by flat formwork 1x2m, placed directly on
diaphragm steel shape H200..
+ Side formwork and flange beam is combined by flat formwork and special
formwork put on modules of steel shape H200x200, wihch are associated with
diagram steel shape H200x200.
+ Core formworks shall be fabricated by modulus 0.25x1.0m, fitness, easy
working, and convenient removing. The formwork is designed by the type of
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3. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
modulus 1m including formworks- supporting bars- bands, ready erected on the
ground and hoisted into its position.
+ Elevation of formwork at each section must be included design deflection of
the bridge and deflection resulting from pre-stressing and deformation of
scaffolding.
• Install bottom formwork
Erection sequence as follows:
+ Formwork boards are placed directly on the diaphragm steel shape H200x200
+ Erection of formwork boards with the length 2m is in the direction of bridge
and parallel to connecting centre line between two piers.
+ After completing bottom formwork installations, in a maximum distance of 4m
between sections, measure the level to adjust the level of beam bottom.
+ Insert the steel wedge below the formwork to adjust the level of formwork
surface (beam bottom).
+ Installation of a special formwork at pier position
• Installation of external wall formwork
Erection sequence as follows:
+ Installation of outside scaffolding system and protective handrail.
+ Completely erecting formworks modulus and supporting frame for beam web
consisting of: web formworks, supporting frames.
+ Hoisting each formwork modulus and supporting frames into exact position.
+ Adjust level of formworks.
+ Tighten the connection bolts, fix geometric position of formwork segment and
install the next segment until finish a span of beam.
• Installation of core formwork
The installing sequence shall be as follows:
+ Formwork system and supporting frame of core formwork shall be installed in
every modulus at 4~6m length, suitable with the capacity of the hoist.
+ Hoisting each formwork modulus into exact position.
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4. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
+ Adjusting elevation and coordinate of formwork.
+ Tighten the connection bolts, fix geometric position of formwork segment and
install the next formwork segment until finish a concreting segmentation.
5. Beam bearing installation
The Contractor will install bearing before casting concrete. Detailed construction is
follows:
• Step 1
Cleanning reinforcement of bearing stone, installing formwork of bearing stone,
casting non-shrinkage motar for bearing stone construction.
• Step 2
When the motar of bearing stone meets requirements of strength, locating exactly
bearing position, defining the horizontal and vertical position of bearing stone,
installing the bearing.
6. Installation of reinforcement, duct and high strength cable
• Installation of reinforcement
Reinforcement is fabricated at yard according to the designed geometric dimension,
numbered and bundled for hoisting into installed position.
Sequence for installing rebar will be prepared by construction team and informed to
foreman during installation of beam rebar with the below principles:
+ Fully installing bars in accordance with the size and location indicated in the
design.
+ Steel structural members must be removed or fixed at designed position by
using supporting bar, chock or tie to resist the excessive movement or bending
during construction process.
+ The distance from formwork surface to steel structural member must be
remained by using supporting bars and chocks. The chocks must be placed in a
suitable distance to make the formwork be free from cracking or excessive
deflection.
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5. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
+ The chocks must be enough hardness, strength and suitable shape to not form
holes around them.
+ The position tolerance for internal reinforcement of concrete:
Bar detail and bending dimension for the rebars must satisfy the
requirement stipulated in Section 5.11 of Bridge Construction
Instruction AASHTO LRFD 98.
The installation tolerance for the super structure as follows:
d ≤ 200 200 < d < 500 500 <d ≤ 2000 d>2000
Tolerance (mm) 5 10 20 30
In there: d may be:
Dimension by measurement direction (mm)
Height of cross section (mm)
• Installation of Duct and high strength Cable
Install holing duct:
+ The holing ducts for high strength tendon are put into designed position before
concreting. The duct is installed segmentally (according to produced length) ducts
are connected together with linking pipe and joint tape around to prevent motar
from inner leakaging.
+ To fix ducts into reinforcement mesh, using D6 bars supporting below and
binding into the mesh at each coordinates adjusting position of the strand
according to design requirements.
+ The head of duct is inserted in the anchor head fixed into beam formwork.
+ The duct is associated to ventilation pipe and grouting chute at the lowest and
the highest points to ensure the pumped grout will completely seal the duct, free
from air bubble.
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6. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
Figure 5 : The process of connection cladding Figure 6: Setting mortar
Wrap joint tape
to be sealed and
free from grout
leakage
Figure 7: Field duct connection
Install duct and high strength tendon:
+ Install duct and high strength tendon, using cupler to connect tendon.
+ High strength tendon will be cut up to designed length, bundled and inserted
into the duct then put into place.
+ Fix cable into head of dead end, locate the dead end.
Notes when installing duct and tendon:
+ Duct position must be installed in right designed place within allowed
tolerance.
+ Curve of cable must be smooth when visually check.
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7. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
+ Duct must have enough tightness so that mortar can not run into there.
7. Placing concrete for beam
• Concrete mix design
Concrete of approach beam of Do Vang bridge has relatively dimension and quantity,
thus mix design work greatly affects the concrete quality. The mix design shall be in
accordance with requirements of Specification.
Concrete shall ensure to be enough strength, waterproofing as requirement of design
also meet demand of yield to ease the construction with minimum cement content.
Minimum compressive strength of cylinder specimen at 28 days shall be 40Mpa to
ensure concrete reach to strength 40Mpa as designed.
In any case, the required slump of concrete shall be 14 ± 2 cm. It shall be rejected if it
is not as requirement. Do not add water to fresh concrete.
Concrete shall have enough adhesiveness and flexibility to ensure it is not segregated
throughout concrete transporting and placing process.
Water-cement ratio in concrete mix shall be less than 0.40.
Concrete mortar shall have setting time over 6 hours.
The parameters of beam concrete:
+ Grade: 40 Mpa
+ Slump: 14 ± 2 cm
• Concrete materials
Beam concrete of Do Vang Bridge as shown in the Specification of Project has
cylinder strength 40MPa.
Mix design shall conform to Specification of Project.
Admixture of concrete is produced by Sika manufacturer. This is a super-plastically
high-tech substance at the thirdly versioned polyme origin to push concrete harden. The
admixture will affect on the below characteristics of concrete:
+ The ability of reducing water is so high.
+ To be deliveried in a great distance.
11
8. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
+ The yield strength is high (decrease the works of placing and compacting)
+ Boost the development of strength
+ Improve the ability of creeping, shrinkage.
• Construction plan layout
+ Currently, construction plan of the Do Vang Bridge has already leveled off material
store yard, reinforcing yard to ready for installing, testing load and placing concrete for
beam.
+ Night lighting system: The Contractor shall arrange fully lighting system along the
service road, beam and all constructing positions throughout the concreting process. The
bulbs used during construction have capacity 500W and shall be disposed at the distance
of 5÷10m per bulb. The minimum illumination level for concreting is 30lux/m2. (When it
comes to horizontal concrete plane – Refer to “Bridge constructing manual” composed by
Pham Huy Chinh- Construction Publisher 2007).
+ Standby power system: The Contractor has standby power system 250KVA in case
of power loss. This system shall be always maintained and checked to find out defects
and treat immediately.
• Construction Equipment
No Equipment Unit Quantity Note
01 Mixing plant 60m3/h each 01
02 Mixer Truck each 03
03 Pumpcrete machine Puztmaiter each 02
04 Generator 250KVA each 01
05 Crane 40T each 01
06 Purchase tackle each 04
07 Jacking and oil pump house Set 02
08 Mortar mixer and pump Set 02
12
9. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
09 Surveyor's level each 01
10 Tachometer each 01
11 Vibrators each 15
12 Pumpcrete pipe m 250
13 Welding machine 400A each 04
14 Pump 60m3/h each 02
• Arrangement manpower
No Equipment Unit Quantity Note
01 Engineering person 03
02 Investigation person 02
03 Woker drive crane person 04
04 Worker support crane person 06
05 Woker drive electric person 02
06 Woker drive mixing plant person 02
07 Worker drive shovel person 02
Worker drive pumpcrete 02
08 person
machine
09 Woker weld person 15
10 Woker jack person 05
• Concrete mixing
Use batching plants that can automatically measure and weigh at Site. The scales shall
be checked accuracy, meet the Specification of Project as stipulated.
Concrete of each batch shall be in accordance with Specification as required.
The slump of concrete must conform to requirements. Therefore, before each concrete
placing time, determine the material moisture to caculate suitable water content for
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10. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
concrete mix.
• Provide concrete
Concrete shall be provided from batching plant to constructed position by truck mixer
and concrete pump.
Time from mixing, placing to compacting concrete is not over 90 minutes to ensure
the works of concreting finish before concrete setting.
Components and slump of concrete mix shall be tested and trial pumped to ensure the
quality of concrete and construction conditions simutanously suitalbe with technical
funtions of pump.
When construction in hot weather, the external surface of concrete must be covered or
whitened to restrict sunlight effect causing hot concrete.
• Method for decrease concrete mix temperature
The Contractor intends to cast concrete from 16 p.m to 10 a.m next morning. In case
of daytime construction, the Contractor shall not construct on the day that temperature is
over 35°C.
Construction in nightime to reduce temperature, direct sunlight causing hot pump pipe
and newly placed concrete.
Concrete mix temperature from batching plant shall be controlled to not excess 25°C
and when placing it is not over 35°C. For these purposes, beside construction in nightime
to decrease temperature, the Contractor also use the following methods to decrease
aggregate temperature:
+ Spray water on balast, gravel: Ballast, gravel in store yard shall be sprayed
periodcally for keeping wet surface to create evaporating mechanism so that
reducing agrregate temperature.
+ Use cool water to mix concrete, water tankers shall be covered from sunlight.
• Pour concrete
+ Concrete is poured by mix truck and pumping machine
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11. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
Concrete placing direction: Concrete shall be casted from the low head to the high
head of beam and placed alternately on all beam webs, ensure that height defference
between these webs is not over 50cm.
Pour concrete vertically by each segment that splayed a 45 0 angle against to horizontal
direction.
Attention when pour concrete
+ Slump of concrete must be as required. Therefore, before each concreting
batch, it is necessary to determine the moisture of material to calculate the suitable
water content for concrete aggregate.
+ The height of the concrete to fall is not more than 1.5 m to avoid segregating.
+ Fresh concrete is poured into formwork by a small amount and using methods
to remain rebar not movement during concreting process.
+ Mixxing speed must ensure that when pouring the above layer, the below layer
has not yet cured to create perfect bonds between layers.
• Tamping
+ In the concrete mix, the Contractor has used superplasticizer with high
mobility of manufacturer Sika to decrease significantly placing and compacting
work.
+ Fresh concrete must be placed into formwork and compacted for each layer
from 250mm to 300mm thickness. By this time, compacting to the previous
concrete layers.
+ During compaction, at the position near ducts, pay attention to advoid touching
the duct to be broken. Do not use vibrator to push concrete.
+ Special attention to concrete quality at anchor heads.
• Curing concrete
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12. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
Curing for concrete beam casted on scaffolding is conducted immediately after
finishing a surface area of concrete beams. Usually use wet sacks to cover on concrete
surface around one hour or when the concrete surface will begin to dry.
After finishing surface and until the surface can resist water (usually after 2 hours of
concreting) must water regularly to the concrete surface which face is finished. When
finishing pouring concrete for girder segments, watering to cure all concrete and wall
formwork. After removing the formwork must water to the concrete regularly throughout
day and nighttime.
Water for curing process shall be fresh water used to mix concrete.
Setting time must prolong at least 7 days from finishing of beam concrete.
• Emegency occurrences that may happen and resolving method.
Treatment method in case of work suspension because of Force Majeure.
The concreting work shall not be executed in the following cases: hard rain, flood,
storm, or the conditions for placing concrete still not ready…
In the event that concreting process is suspended because of the interruption in
concrete providing source (long-time traffic jam, accident…) the problem shall be
resolved as below:
+ Use the standby mixing plants at the Site.
+ If the quantity of concrete required to place is further more than capacity of standby
mixing plants, the construction must be suspended and the Contractor continuously
compacts to finish the casted concrete. In the vertical direction, concrete shall be
made by diagonal section bias an angle ≤ 450 against horizontal plane. This special
construction joint shall be treated, roughed in accordance with procedure and
specification for the next concreting stage.
Measure to prevent honeycomb:
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13. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
Honeycomb at concrete is easy to happen because of special shape of box girder.
Positions where honeycomb can happen and method which is carried out in process of
pouring concrete to prevent honeycomb is showed in below table:
No. Position where honeycomb can Reason Preventative measure
happen
1 The lower chamfer of web Concrete pouring to Need to guide workers
web is easy to flow not hesitate when
to bottom slab compact concrete
Workers hesitate
when compact
concrete because
concrete flow to
bottom slab
The lower chamfer The vibrating tampers
of web can’t be are often associated
compacted well with a burning
because outside web bamboo or a straight
isn’t straight pipe to pass thread
along shape of
diagonal web
Projector flashlight
into the side of web
These parts will be
hammered handwork
by wooden hammer
It is difficult to Vibrator will be
compact by vibrator associated with a
2 The angle of bottom slab
straight bar to compact
that part.
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14. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
The claddings will Pour concrete slowly
3 The lower part of cladding prevent compacting and compact concrete
concrete below them more carefully
4 The anchorage zone Much reinforcement Compact carefully
Beam casting formwork
No. Problem Resolve
Load capacity of formwork Before fabricating the formwork shall be
caculated, designed to ensure enough load
1
capacity. Checking their quality and geometrical
dimension before leaving workshop.
Formwork that is bad The formworks shall be checked, taken-over in
quality, defected during quality and geometrical dimension to
2
transportation immediately discover and substitute the defected
boards.
The camber of formwork During installation, the formwork elevation shall
resulting from designed be adjusted to be suitable with the camber.
3 camber of the bridge,
stressing prestressed cable,
scaffolding deformation
8. Prestressed cable tension
• Preparation work
It is necessary to make sure that before constructing all persons attending directly in
stretching works, especially technicants and stretching team leaders must have full
knowledge of stretch controlling steps to ensure the technical quality and safety
regulation.
Check concrete strength (taking sample before stressing). The strength shall reach to
90%Rtk (90%*40Mpa = 36 for cylinder sample).
Check jack, pump, jack bracket, chain hoist and work platform.
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15. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
+ Jack, pump for stressing shall be checked and approved before using.
+ Jack and pump shall be inspected by specialist authority.
+ Jack shall be inspected in the following moments:
• Before using to avoid accident or occurrence.
• Change jack set.
+ Anchor test:
• Anchor using for Project must be in accordance with Specification and
inspected to pass testing criterium and approved by Engineer.
• Anchor using for installation shall be free from crack, warp, and the chap
must be sealed with anchor.
Show stressing steps on the visble positions for the stressing team leader.
Fill up enough points stipulated in stressing note.
• Stressing equipment.
Prestressed Cable
High strength cable shall use kind of tendon as 7 lowly saged plies 12 strands 15.2m
bundled cable Grade 270 according to ASTM A416 – 90A standard.
No Item Value
1 Nominal diameter 15.2 mm
2 Area of cross section 140 mm2
3 Ultimate strength 1860 Mpa
4 Yield point stress 1670 MPa
Prestressed cable shall be protected in store that has screen, be dry, apart 30cm from
the ground.
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16. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
Pretressed cable must have Certificate of Producer approved by Employer and
Engineer.
Test for tendon in accordance with Design Document and criterium: breaking force,
elastic modulus, yeild strength, elongation, dimension of each ply in tendon, condition of
external surface. Any change that not be in accordance with Design Document shall be
approved in writing by Design Unit, Employer, Engineer beforce constructing.
Anchor
Use imported anchor of OVM manufacturer for cable 15,2mm .
Imported anchor must have Quality Certificate of Manufacturer.
Jack
All of jacks, oil pumps shall be inspected before using.
Jack Area Strain Sroke
Type of
No pittong max pittong Note
Name Mark Pump
(cm2) (KN) (mm)
Horizontally
1 YCQ500Q 0707 ZB4 - 500 1000 5000 200
stretching
Horizontally
2 YCQ500Q 1001 ZB4 - 500 1000 5000 200
stretching
• Prestressed cable tension
Use one-head tensioning method. Using jack 500T applying for tendon as 7 lowly
saged plies 12 strands 15.2m bundled cable.
Stretch every twin cables symmetrically through centreline of beam in the following
sequence:
+ From centerline to outside.
+ From neutral axis to outside.
Sequence of stressing tendons on each segment: Stressing longitudinally then
stretching horizontally prestressed cable of bridge.
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