Mega Prefab is a complete service provider of structural precast and post-tensioned concrete. We are involved in all the phases of the project. We will design, manufacture, deliver and install our products. With more than 16 years experience in the business, we have optimized our structural elements to be efficient, safe and low cost.
In post-tension, the concrete units are first cast by incorporating ducts or grooves to house the tendons .when the concrete attains sufficient strength, the high-tensile wires are tensioned by means of jack bearing on the end face of the member and anchored by wedges or nuts.
This document provides the preface and contents for the book "Steel Structures: Practical Design Studies" by T.J. MacGinley. The preface outlines that the book presents principles and sample designs for major steel-framed building types, with designs now conforming to limit state theory codes. Not all analyses and checks can be shown for each design. The contents provide an overview of the topics covered in each chapter, including preliminary design methods, single-storey buildings, multi-storey buildings, floor systems, tall buildings, wide-span buildings and more. Design exercises are included at the end of most chapters.
Post-tensioning is an effective alternative for earthquake-prone regions and dense populations in India. It has advantages over ordinary reinforced concrete like higher seismic resilience, less concrete usage, stiffer foundations, and faster construction. Post-tensioning involves threading steel tendons through ducts and tensioning them after concrete pouring. It provides better crack control, economy, quality, and efficiency. While widely used in other countries, post-tensioning is not yet common in India but has applications in slabs, buildings, and foundations.
This document discusses the analysis of cable-stayed bridges. It begins with an introduction to cable-stayed bridges, noting that they usually span 200 to 800 meters and have towers from which cables support the bridge deck. It then discusses the various components of cable-stayed bridges such as the pylons, cables, and deck. The document also summarizes the different modeling, analysis methods like linear and non-linear, and software that can be used to analyze cable-stayed bridges. It concludes by stating that cable-stayed bridges are more economical than suspension bridges and that area object modeling is more accurate than spine modeling.
In engineering, a truss is a structure that "consists of two-force members only, where the members are organized so that the assemblage as a whole behaves as a single object".
03-Introduction to Structural Steel Design (Steel Structural Design & Prof. S...Hossam Shafiq II
This document discusses the advantages and disadvantages of steel as a structural material. It notes that steel has high strength, uniformity, elasticity, permanence, ductility, and toughness. However, it requires maintenance against corrosion and fireproofing. Steel is also susceptible to buckling if members become too long and slender. Additionally, steel strength can reduce due to fatigue, brittle failure, and residual stresses. The document provides information on common steel grades used in design and their properties.
The document discusses reinforcement in two-way slabs and footing design. It describes two types of shear failure in slabs: one-way shear and two-way shear. One-way shear results in inclined cracking and pull-out of negative reinforcement from the slab. Two-way shear can result in either inclined cracking or the slab sliding down the column. The critical perimeter for two-way shear is located at d/2 from the column face, where d is the effective depth of the slab. Formulas are provided to calculate the nominal shear resistance Vn of slabs under two-way shear with negligible moment transfer.
This document provides an overview of member behavior for beams and columns in seismic design. It discusses the types of moment resisting frames and the principles for designing special moment resisting frames, including strong-column/weak-beam design, avoiding shear failure, and providing ductile details. Beam and column design considerations are covered, such as dimensions, reinforcement, and shear capacity. Beam-column joint design is also summarized, including dimensions, shear determination, and strength.
In post-tension, the concrete units are first cast by incorporating ducts or grooves to house the tendons .when the concrete attains sufficient strength, the high-tensile wires are tensioned by means of jack bearing on the end face of the member and anchored by wedges or nuts.
This document provides the preface and contents for the book "Steel Structures: Practical Design Studies" by T.J. MacGinley. The preface outlines that the book presents principles and sample designs for major steel-framed building types, with designs now conforming to limit state theory codes. Not all analyses and checks can be shown for each design. The contents provide an overview of the topics covered in each chapter, including preliminary design methods, single-storey buildings, multi-storey buildings, floor systems, tall buildings, wide-span buildings and more. Design exercises are included at the end of most chapters.
Post-tensioning is an effective alternative for earthquake-prone regions and dense populations in India. It has advantages over ordinary reinforced concrete like higher seismic resilience, less concrete usage, stiffer foundations, and faster construction. Post-tensioning involves threading steel tendons through ducts and tensioning them after concrete pouring. It provides better crack control, economy, quality, and efficiency. While widely used in other countries, post-tensioning is not yet common in India but has applications in slabs, buildings, and foundations.
This document discusses the analysis of cable-stayed bridges. It begins with an introduction to cable-stayed bridges, noting that they usually span 200 to 800 meters and have towers from which cables support the bridge deck. It then discusses the various components of cable-stayed bridges such as the pylons, cables, and deck. The document also summarizes the different modeling, analysis methods like linear and non-linear, and software that can be used to analyze cable-stayed bridges. It concludes by stating that cable-stayed bridges are more economical than suspension bridges and that area object modeling is more accurate than spine modeling.
In engineering, a truss is a structure that "consists of two-force members only, where the members are organized so that the assemblage as a whole behaves as a single object".
03-Introduction to Structural Steel Design (Steel Structural Design & Prof. S...Hossam Shafiq II
This document discusses the advantages and disadvantages of steel as a structural material. It notes that steel has high strength, uniformity, elasticity, permanence, ductility, and toughness. However, it requires maintenance against corrosion and fireproofing. Steel is also susceptible to buckling if members become too long and slender. Additionally, steel strength can reduce due to fatigue, brittle failure, and residual stresses. The document provides information on common steel grades used in design and their properties.
The document discusses reinforcement in two-way slabs and footing design. It describes two types of shear failure in slabs: one-way shear and two-way shear. One-way shear results in inclined cracking and pull-out of negative reinforcement from the slab. Two-way shear can result in either inclined cracking or the slab sliding down the column. The critical perimeter for two-way shear is located at d/2 from the column face, where d is the effective depth of the slab. Formulas are provided to calculate the nominal shear resistance Vn of slabs under two-way shear with negligible moment transfer.
This document provides an overview of member behavior for beams and columns in seismic design. It discusses the types of moment resisting frames and the principles for designing special moment resisting frames, including strong-column/weak-beam design, avoiding shear failure, and providing ductile details. Beam and column design considerations are covered, such as dimensions, reinforcement, and shear capacity. Beam-column joint design is also summarized, including dimensions, shear determination, and strength.
Various Reasons of Cracks in Buildings
Cracks can occur due to chemical reactions in construction materials, changes in temperature and climate, foundation movements and settling of buildings, environmental stresses like nearby trains, earth quakes etc. Faulty design, bad... more
The document discusses the principles and applications of prestressing in construction. It describes how prestressing uses tensioned steel strands or wires to put concrete members into compression through pre-tensioning or post-tensioning. This counters the tensile stresses experienced by concrete and allows for longer spans, reduced member depth, crack control, and cost savings. Common applications of prestressing include bridges, flyovers, buildings, parking structures, and industrial structures.
- Deep beams are defined as beams with a shear span to depth ratio of less than 2. They behave differently than ordinary beams due to two-dimensional loading and non-linear stress distributions.
- Deep beams transfer significant load through compression forces between the load and supports. Shear deformations are more prominent.
- Design of deep beams requires considering two-dimensional effects, non-linear stress distributions, and large shear deformations. Procedures include checking minimum thickness, designing for flexure and shear, and detailing reinforcement.
This document discusses bolted connections used in structural engineering. It begins by explaining why connection failures should be avoided, as they can lead to catastrophic structural failures. It then classifies bolted connections based on their method of fastening, rigidity, joint resistance, fabrication location, joint location, connection geometry, and type of force transferred. It describes different types of bolts and bolt tightening techniques used for friction grip connections. It discusses advantages and drawbacks of bolted connections compared to riveted or welded connections. The document provides detailed information on design and behavior of various bolted connections.
Steel is a versatile material that is commonly used for large scale construction projects due to its strength, durability, and cost-effectiveness. Steel trusses are a type of structure frequently employed in buildings to provide support for roofs, floors, and other loads. They consist of compression and tension elements arranged in a triangulated pattern, allowing them to efficiently span long distances with minimal material. Common types of steel truss designs include Pratt, Warren, and Fink configurations. Truss members are often made of angles, channels, tubes, or other standard steel sections joined together with bolted or welded connections.
The document discusses the design of columns in concrete structures. It covers several topics related to column design including: member strength and capacity versus section capacity, moment magnification, issues regarding slenderness effects, P-Delta analysis, and effective design considerations. The key steps in column design are outlined, including determining loads, geometry, materials, checking slenderness, computing design moments and capacities, and iterating the design as needed. Factors that influence column capacity such as slenderness, bracing, and effective length and stiffness are also described.
The document discusses shear design of beams. It covers shear strength, which depends on the web thickness and h/t ratio to prevent shear buckling. Shear strength is calculated as 60% of the tensile yield stress. Block shear failure is also discussed, where the strength is governed by the shear and net tension areas. An example calculates the maximum reaction based on block shear for a coped beam connection.
In science, buckling is a mathematical instability, leading to a failure mode.
Buckling is characterized by a sudden sideways failure of a structural member subjected to high compressive stress, where the compressive stress at the point of failure is less than the ultimate compressive stress that the material is capable of withstanding
This document discusses pile caps and their construction. It contains several sections:
- An introduction to pile caps, which distribute loads from columns over piles.
- Reasons for using pile caps, such as stabilizing piles and transmitting loads to the ground.
- Advantages of precast pile caps like being made off-site and rapid construction.
- The pile driving process which involves excavation, lifting piles, and hammering them into the ground.
- How pile caps are constructed by cutting piles, forming, reinforcing, and pouring concrete.
- Potential issues like delays from rain and deformities or failures of improperly installed pile caps.
CE 72.32 (January 2016 Semester): Lecture 1a - Overview of Tall BuildingsFawad Najam
Humans have historically admired tall structures for their visibility and social status. The document discusses the evolution of tall buildings from ancient structures like pyramids to modern skyscrapers, driven by urbanization. It describes key milestones like the development of tubular structural systems to enable increasingly taller buildings. The design of modern tall buildings requires integrated, multi-disciplinary teams and continues to be enabled by new technologies.
Capacity of strengthened Reinforced concrete columnsKhaled Mahmoud
this presentation show main points of research focused on the analysis of concrete and steel jackets to get simple equations for design. Therefore, an experimental program consists of twenty columns strengthened with concrete jackets and steel jackets are performed. The results were compared with some of the design equations in available literature. These equations were modified to match the theoretical and experimental results. Recommendations for column behavior after strengthening are presented to help structural engineers to maximize the benefits of strengthening operation.
CE 72.52 - Lecture 8a - Retrofitting of RC MembersFawad Najam
The document outlines a presentation on retrofitting concrete structures. It discusses two approaches to retrofitting: global (system) strengthening which adds new elements to enhance stiffness, and local (element) strengthening which targets insufficient member capacities. Examples of global retrofitting mentioned include adding reinforced concrete shear walls and buckling restrained braces. Local retrofitting examples discussed are reinforcement concrete jacketing of columns and beams.
This document discusses T-beams, which are more suitable than rectangular beams in reinforced concrete. There are two types of T-beams: monolithic and isolated. It provides notations and code recommendations for T-beams from IS: 456. There are three cases for finding the depth of the neutral axis in a T-beam: when it lies in the flange, in the rib, or at the junction. An example problem is worked through to find the moment of resistance for a given T-beam section using the provided concrete and steel properties.
Reinforced concrete is concrete that is strengthened with rebar or steel reinforcement. It is stronger than plain concrete due to its ability to withstand both compressive and tensile stresses. The steel reinforcement provides tensile strength, while the concrete primarily resists compressive forces and protects the rebar from corrosion. Proper placement of the rebar within the formwork prior to pouring concrete is important to achieve the structural strength of the reinforced concrete. Testing of the concrete is also done to ensure it meets the required strength standards. Reinforced concrete has many advantages over plain concrete, including higher strength, durability, resistance to fire and weathering, and lower lifetime maintenance costs.
This document provides an overview of the design of compression members (columns) in reinforced concrete structures. It discusses various types of columns based on reinforcement, loading conditions, and slenderness ratio. It describes the classification of columns as short or slender. The document also covers effective length, braced vs unbraced columns, codal provisions for reinforcement, and functions of longitudinal and transverse reinforcement. Key points include types of column reinforcement, minimum reinforcement requirements, cover requirements, and assumptions for the limit state of collapse under compression.
Digital construction for DSD - relocation of Sewage Treatment PlantStephen Au
This document summarizes the relocation of the Sha Tin Sewage Treatment Works project in Hong Kong, which will involve constructing caverns underground and relocating sewage treatment facilities. The $811 million project is led by the Drainage Services Department and AECOM Asia Company Limited, with the main contractor being China State Joint Venture. Extensive use of BIM and other technologies are planned over the 13-year, multi-phase project to facilitate planning, design, construction and safety training while minimizing disruptions to local residents.
Reinforcement concrete and properties of matrial VIKAS4210607
The document discusses the properties and characteristics of reinforced concrete and its constituent materials - concrete and steel reinforcement. It provides information on:
- Concrete is composed of cement, aggregate and water that hardens over time to form a durable stone-like material. Reinforced concrete includes steel reinforcement to increase its tensile strength.
- The properties of concrete and steel depend on their composition and standards. Concrete properties include compressive strength and shrinkage properties. Steel properties include yield strength.
- Permissible stresses values for concrete and steel under different loads and grades are defined in codes based on material testing. Reinforced concrete exploits the composite action of concrete and steel to form an efficient structural material.
This document discusses different methods of prestressing concrete, including pretensioning and post-tensioning. Pretensioning involves stressing steel tendons before placing concrete around them, while post-tensioning involves stressing tendons after the concrete has cured using hydraulic jacks. Post-tensioning allows for longer spans, thinner slabs, and more architectural freedom compared to conventional reinforced concrete or pretensioned concrete. Common applications of post-tensioning include parking structures, bridges, and building floors and roofs.
Various Reasons of Cracks in Buildings
Cracks can occur due to chemical reactions in construction materials, changes in temperature and climate, foundation movements and settling of buildings, environmental stresses like nearby trains, earth quakes etc. Faulty design, bad... more
The document discusses the principles and applications of prestressing in construction. It describes how prestressing uses tensioned steel strands or wires to put concrete members into compression through pre-tensioning or post-tensioning. This counters the tensile stresses experienced by concrete and allows for longer spans, reduced member depth, crack control, and cost savings. Common applications of prestressing include bridges, flyovers, buildings, parking structures, and industrial structures.
- Deep beams are defined as beams with a shear span to depth ratio of less than 2. They behave differently than ordinary beams due to two-dimensional loading and non-linear stress distributions.
- Deep beams transfer significant load through compression forces between the load and supports. Shear deformations are more prominent.
- Design of deep beams requires considering two-dimensional effects, non-linear stress distributions, and large shear deformations. Procedures include checking minimum thickness, designing for flexure and shear, and detailing reinforcement.
This document discusses bolted connections used in structural engineering. It begins by explaining why connection failures should be avoided, as they can lead to catastrophic structural failures. It then classifies bolted connections based on their method of fastening, rigidity, joint resistance, fabrication location, joint location, connection geometry, and type of force transferred. It describes different types of bolts and bolt tightening techniques used for friction grip connections. It discusses advantages and drawbacks of bolted connections compared to riveted or welded connections. The document provides detailed information on design and behavior of various bolted connections.
Steel is a versatile material that is commonly used for large scale construction projects due to its strength, durability, and cost-effectiveness. Steel trusses are a type of structure frequently employed in buildings to provide support for roofs, floors, and other loads. They consist of compression and tension elements arranged in a triangulated pattern, allowing them to efficiently span long distances with minimal material. Common types of steel truss designs include Pratt, Warren, and Fink configurations. Truss members are often made of angles, channels, tubes, or other standard steel sections joined together with bolted or welded connections.
The document discusses the design of columns in concrete structures. It covers several topics related to column design including: member strength and capacity versus section capacity, moment magnification, issues regarding slenderness effects, P-Delta analysis, and effective design considerations. The key steps in column design are outlined, including determining loads, geometry, materials, checking slenderness, computing design moments and capacities, and iterating the design as needed. Factors that influence column capacity such as slenderness, bracing, and effective length and stiffness are also described.
The document discusses shear design of beams. It covers shear strength, which depends on the web thickness and h/t ratio to prevent shear buckling. Shear strength is calculated as 60% of the tensile yield stress. Block shear failure is also discussed, where the strength is governed by the shear and net tension areas. An example calculates the maximum reaction based on block shear for a coped beam connection.
In science, buckling is a mathematical instability, leading to a failure mode.
Buckling is characterized by a sudden sideways failure of a structural member subjected to high compressive stress, where the compressive stress at the point of failure is less than the ultimate compressive stress that the material is capable of withstanding
This document discusses pile caps and their construction. It contains several sections:
- An introduction to pile caps, which distribute loads from columns over piles.
- Reasons for using pile caps, such as stabilizing piles and transmitting loads to the ground.
- Advantages of precast pile caps like being made off-site and rapid construction.
- The pile driving process which involves excavation, lifting piles, and hammering them into the ground.
- How pile caps are constructed by cutting piles, forming, reinforcing, and pouring concrete.
- Potential issues like delays from rain and deformities or failures of improperly installed pile caps.
CE 72.32 (January 2016 Semester): Lecture 1a - Overview of Tall BuildingsFawad Najam
Humans have historically admired tall structures for their visibility and social status. The document discusses the evolution of tall buildings from ancient structures like pyramids to modern skyscrapers, driven by urbanization. It describes key milestones like the development of tubular structural systems to enable increasingly taller buildings. The design of modern tall buildings requires integrated, multi-disciplinary teams and continues to be enabled by new technologies.
Capacity of strengthened Reinforced concrete columnsKhaled Mahmoud
this presentation show main points of research focused on the analysis of concrete and steel jackets to get simple equations for design. Therefore, an experimental program consists of twenty columns strengthened with concrete jackets and steel jackets are performed. The results were compared with some of the design equations in available literature. These equations were modified to match the theoretical and experimental results. Recommendations for column behavior after strengthening are presented to help structural engineers to maximize the benefits of strengthening operation.
CE 72.52 - Lecture 8a - Retrofitting of RC MembersFawad Najam
The document outlines a presentation on retrofitting concrete structures. It discusses two approaches to retrofitting: global (system) strengthening which adds new elements to enhance stiffness, and local (element) strengthening which targets insufficient member capacities. Examples of global retrofitting mentioned include adding reinforced concrete shear walls and buckling restrained braces. Local retrofitting examples discussed are reinforcement concrete jacketing of columns and beams.
This document discusses T-beams, which are more suitable than rectangular beams in reinforced concrete. There are two types of T-beams: monolithic and isolated. It provides notations and code recommendations for T-beams from IS: 456. There are three cases for finding the depth of the neutral axis in a T-beam: when it lies in the flange, in the rib, or at the junction. An example problem is worked through to find the moment of resistance for a given T-beam section using the provided concrete and steel properties.
Reinforced concrete is concrete that is strengthened with rebar or steel reinforcement. It is stronger than plain concrete due to its ability to withstand both compressive and tensile stresses. The steel reinforcement provides tensile strength, while the concrete primarily resists compressive forces and protects the rebar from corrosion. Proper placement of the rebar within the formwork prior to pouring concrete is important to achieve the structural strength of the reinforced concrete. Testing of the concrete is also done to ensure it meets the required strength standards. Reinforced concrete has many advantages over plain concrete, including higher strength, durability, resistance to fire and weathering, and lower lifetime maintenance costs.
This document provides an overview of the design of compression members (columns) in reinforced concrete structures. It discusses various types of columns based on reinforcement, loading conditions, and slenderness ratio. It describes the classification of columns as short or slender. The document also covers effective length, braced vs unbraced columns, codal provisions for reinforcement, and functions of longitudinal and transverse reinforcement. Key points include types of column reinforcement, minimum reinforcement requirements, cover requirements, and assumptions for the limit state of collapse under compression.
Digital construction for DSD - relocation of Sewage Treatment PlantStephen Au
This document summarizes the relocation of the Sha Tin Sewage Treatment Works project in Hong Kong, which will involve constructing caverns underground and relocating sewage treatment facilities. The $811 million project is led by the Drainage Services Department and AECOM Asia Company Limited, with the main contractor being China State Joint Venture. Extensive use of BIM and other technologies are planned over the 13-year, multi-phase project to facilitate planning, design, construction and safety training while minimizing disruptions to local residents.
Reinforcement concrete and properties of matrial VIKAS4210607
The document discusses the properties and characteristics of reinforced concrete and its constituent materials - concrete and steel reinforcement. It provides information on:
- Concrete is composed of cement, aggregate and water that hardens over time to form a durable stone-like material. Reinforced concrete includes steel reinforcement to increase its tensile strength.
- The properties of concrete and steel depend on their composition and standards. Concrete properties include compressive strength and shrinkage properties. Steel properties include yield strength.
- Permissible stresses values for concrete and steel under different loads and grades are defined in codes based on material testing. Reinforced concrete exploits the composite action of concrete and steel to form an efficient structural material.
This document discusses different methods of prestressing concrete, including pretensioning and post-tensioning. Pretensioning involves stressing steel tendons before placing concrete around them, while post-tensioning involves stressing tendons after the concrete has cured using hydraulic jacks. Post-tensioning allows for longer spans, thinner slabs, and more architectural freedom compared to conventional reinforced concrete or pretensioned concrete. Common applications of post-tensioning include parking structures, bridges, and building floors and roofs.
SterlingPT Pvt. Ltd, previously known as Post Tension Services Pakistan Pvt. Ltd. (PTSP) specializes in design and installation of Post Tensioning (PT) systems throughout Pakistan. SterlingPT is an engineering franchise of Sterling Engineering and Design Group Ltd. (www.segoc.com). A USA based company with extensive Post Tensioning (PT) design and construction experience.
SterlingPT typically reviews the structural design of the project with structural engineer and determine the feasibility use of PT. If PT is deemed feasible, SterlingPT submits the proposal defining in detail the SterlingPT scope of work. The quote typically includes providing the cost for PT cables, all accessories, PT System installation and its stressing.
The design of the PT is in accordance with relevant ACI and IS codes. Typically, SterlingPT requires 3 to 4 weeks to deliver Post Tensioned cables after receipt of order.
We have been working in Pakistan since 2009 and have done number of successful projects. Our experience to date in the Pakistan market has yielded some following valuable information.
. PT reduces self-weight of structure,
. Cost of reinforcement is typically up to 25% less than that of conventional reinforcing,
. Formwork can be stripped after 7days,
. PT cable strength is four times greater than that of conventional re-bar strength,
. Effective in Parking Structures, Residential and Industrial Structures, Walls, Columns and Slabs,
This document provides engineering plans and calculations for the site development of a dental office space. It includes a cover page, legend, site layout plan, drainage plan, grading plan, and appendices with detailed drainage and pavement design calculations. The calculations determine appropriate sizes for dry wells and bioswales to manage stormwater runoff. Pavement designs calculate thicknesses for hot mix asphalt, aggregate base, and aggregate subbase layers to support the expected traffic.
The document summarizes an experiment comparing pre-stressed/post-tensioned reinforcement to traditional steel reinforcement in concrete slabs. Two slabs were fabricated - a post-tensioned slab with 3/4" threaded rod and a rebar reinforced slab with #4 rebar. Material properties were tested, including concrete compressive strength from cylinders. The post-tensioned slab resisted 3.135 kips before cracking compared to 1.200 kips for the rebar slab. Post-tensioning doubled the load at cracking and increased ultimate strength by 1.2x. While post-tensioning increased cracking load and strength, it reduced ductility compared to the rebar slab. The results show post-tensioning can
MSN was established in 2005 in Dubai to provide post-tensioning design and construction services. It now has over 70 staff across the UAE, Saudi Arabia, and Malaysia. MSN has worked on over 110 post-tensioning projects across residential, commercial, and public sectors. Notable projects include a 48-story tower in Abu Dhabi, staff accommodation in Dubai completed in 11 months, and the Ministry of Interior building in Malaysia. MSN prioritizes using qualified materials and software to ensure high-quality, durable construction.
This document provides design specifications for prestressed concrete bridges. It includes general requirements and materials for prestressed concrete in Part A. It specifies the concrete strength, prestressing steel, and non-prestressed reinforcement requirements. It also defines many terms related to prestressed concrete design.
Part B covers the analysis of prestressed concrete structures. It states that members must be proportioned for adequate strength using the specifications as minimum guidelines. Continuous beams and other statically indeterminate structures must be designed for adequate strength and satisfactory behavior. It also provides requirements for analyzing simple span and continuous prestressed concrete girders.
1) The document discusses the design of shafts subjected to different loading conditions including bending, torsion, combined bending and torsion, fluctuating loads, and axial loads.
2) Formulas are provided to calculate the equivalent bending moment and equivalent twisting moment for shafts under various loading conditions.
3) Examples are presented to demonstrate how to use the formulas and determine the necessary shaft diameter based on allowable stresses.
Infrastructure and Unbonded Post TensioningAMSYSCO Inc.
The document discusses the use of unbonded post-tensioning for infrastructure projects. It begins with an overview of concrete versus asphalt pavements. Unbonded post-tensioning can be used for applications like airport runways, parking lots, and pedestrian bridges. The document then presents three case studies where unbonded post-tensioning was used: a road project in Wayzata Bay with poor soil conditions, an emergency vehicle operator course, and a reconstruction project on Buford Avenue. It concludes that unbonded encapsulated post-tensioning is an effective alternative to reinforced concrete or asphalt for infrastructure projects.
The document presents the design of a post-tensioned prestressed concrete tee beam and slab bridge deck. Key details include:
- The bridge will have an effective span of 30m and width of 7.5m with 600mm kerbs and 1.5m footpaths on each side.
- The project team will design the bridge to meet Class AA loading standards for a national highway.
- The bridge will have 4 main girders spaced at 2.5m intervals with a 250mm thick deck slab cast between them.
- The document outlines the design process for the interior slab panel, longitudinal girders, and calculation of design moments and shear forces. Properties of the main girder cross
All reinforced concrete beams crack, generally starting at loads well below service level, and possibly even prior to loading due to restrained shrinkage. Flexural cracking due to loads is not only inevitable, but actually necessary for the reinforcement to be used effectively. Prior to the formation of flexural cracks, the steel stress is no more than n times the stress in the adjacent concrete, where n is the modular ratio E5/Ec. For materials common in current practice, n is approximately 8.
This document discusses the analysis of continuous prestressed concrete beams. It provides background on the development of prestressed concrete, noting that Eugene Freyssinet was key in recognizing concrete creep and developing successful prestressed concrete designs in the 1920s. It then discusses three philosophies for analyzing prestressed concrete - permissible stress design, ultimate strength design, and load-balancing design. Finally, it outlines the process for section design of prestressed concrete beams, including using Magnel diagrams to design the prestressing force based on satisfying stress limits.
Post-tensioning is a method of reinforcing (strengthening) concrete or other materials with high-strength steel strands or bars, typically referred to as tendons. Post-tensioning applications include office and apartment buildings, parking structures, slabs-on-ground, bridges, sports stadiums, rock and soil anchors, and water-tanks.
>>>Published by Post-Tensioning Institute
Prestressed concrete is a method that applies compressive force to reinforced concrete in order to counteract tensile forces. This prevents cracking and allows concrete to be treated as an elastic material. There are two main methods: pre-tensioning, where tendons are tensioned before casting, and post-tensioning, where tendons are tensioned after casting using ducts. Prestressed concrete enables longer spans, reduces material usage, and improves durability compared to reinforced concrete. However, it requires higher quality materials and specialized equipment, which increases costs.
This document outlines the advantages of using post-tensioning in building structures. Post-tensioning allows for longer spans, reduced floor thickness, increased floor area, faster construction speeds, and reduced material usage. It discusses common post-tensioning systems used in building floors and specialized structural elements. Post-tensioning provides more flexible and economical building structures compared to other methods.
The document discusses the design of columns and footings in concrete structures. It covers various topics related to column design including classification of columns based on type of reinforcement, loading, and slenderness ratios. Short columns subjected to axial loads with or without eccentricity are analyzed. Design aspects such as effective length, minimum reinforcement requirements, cover and transverse tie spacing are described based on code specifications. Equations for equilibrium of uniformly loaded short columns are also presented.
Post-tensioning is simply a method of producing prestressed concrete, masonry, and other structural elements. Post-tensioning is a form of prestressing. Prestressing simply means that the steel is stressed (pulled or tensioned) before the concrete has to support the service loads. Most precast, prestressed concrete is actually pre-tensioned-the steel is pulled before the concrete is poured. Post-tensioned concrete means that the concrete is poured and then the tension is applied-but it is still stressed before the loads are applied so it is still prestressed.
This document provides a brief history of prestressed concrete, beginning in 1824 with the development of Portland cement. It then outlines several important developments in prestressed concrete technology from the late 19th century through the mid-20th century by innovators from various countries. These include early uses of steel in concrete, prestressing methods like pre-tensioning and post-tensioning, and development of high-strength steel and anchoring systems. It also mentions increased use of prestressed concrete during World War 2 and establishment of professional organizations to support the field.
ANALYSIS & DESIGN ASPECTS OF PRE-STRESSED MEMBERS USING F.R.P. TENDONSGirish Singh
The purpose of this investigation is mainly a brief explanation about the advantages of FRP over steel. The various uses and advantages of FRP are explained in this project. In this project, we have taken a section of 3m length, 200mm width and 300mm depth and using a parabolic tendon of eccentricity 100mm at the centre. We have design the section for FRP as well as steel with the above data. The final stresses obtained is being verified with the help of Ansys software. We have shown the result of steel straight tendon only in this mini project.
This document provides a design summary for Bridge 205 of the I-35W Extension Project. The project involved designing pre-tensioned prestressed concrete girders for the seven spans of the bridge using PGSuper software. Span 2, the longest at 230.58 feet, required 15 Tx70 girders to meet stress limits, while the other spans used mostly 5 Tx54 girders, except Span 4 which used 5 Tx70 girders. Analysis was performed for moments, shears, stresses, deflections and other limit states. Design details such as mild steel reinforcement, girder schedules, and shop drawings are provided to summarize the project.
This document discusses prestressed concrete and provides details on:
- The definition and principle of prestressing concrete by applying compression prior to external loads
- Common prestressing methods like hydraulic, mechanical, electrical, and chemical prestressing
- Tests conducted on prestressed concrete components like post-tensioned splices and cast-in-place splices
- Advantages of prestressed concrete like reduced materials and increased strength
- Applications in bridges, buildings, water tanks, and more
- A case study on widening the Harrods Creek Arch Bridge using prestressed concrete
This document provides an overview of post-tensioning, including:
- Typical applications like suspended slabs, foundations, and cantilevered structures
- The two main types are bonded and unbonded post-tensioning
- Advantages include material savings, quicker construction, and increased performance, while disadvantages include complexity and potential corrosion issues
- The construction process involves placing ducts, casting concrete, tensioning tendons, and anchoring them
- Real-life projects in Morocco and Malaysia utilized post-tensioning for large structures like malls and transit systems.
Joints in concrete structures serve three main purposes: to allow work to resume after delays, to relieve stresses, and to control cracking. There are three main types of joints: construction joints between concrete placements, expansion joints that allow movement between adjacent sections, and contraction joints that create weakened planes to regulate cracking. Contraction joints are usually formed, tooled, or sawcut, while expansion joints may use joint formers. Proper jointing requires sealants with properties like flexibility, adhesion, and resistance to aging and chemicals.
This document provides information about prestressed concrete, specifically focusing on post-tensioning methods. It defines post-tensioning as a method of reinforcing concrete with high-strength steel strands called tendons. After the concrete cures, the tendons are tensioned using hydraulic jacks and wedged into place to transfer pressure to the concrete. There are benefits to post-tensioning like allowing longer spans, thinner structures, and reduced cracking compared to conventional reinforced concrete. The document discusses bonded and unbonded post-tensioning methods and provides examples of applications like buildings, bridges, and parking structures.
Pre-stressed concrete uses tensioned steel cables or rods to put concrete members under compression and increase their strength. It allows for longer spans than reinforced concrete. There are three methods: pre-tensioned concrete uses tensioned tendons before pouring concrete; bonded post-tensioned concrete uses tendons tensioned after pouring; unbonded post-tensioned concrete uses individually coated tendons without bonding to the concrete. Prestressed concrete has advantages like less cracking and material efficiency but also disadvantages like higher costs.
Prestressing is a technique where tension is applied to concrete before hardening to improve its performance. There are two main types - pre-tensioning and post-tensioning. Pre-tensioning involves tensioning steel tendons before casting concrete, while post-tensioning tensions tendons after casting. There are losses in prestress over time from factors like elastic shortening, shrinkage, creep, and steel relaxation. Proper materials and design are needed to account for these losses and ensure structures perform as intended.
CCL Post Tensioned Concrete Slab BrochureCCL Concrete
CCL is a global engineering company specializing in post-tensioned concrete solutions. They provide design, material, and construction services for post-tensioned slabs. CCL has extensive experience from projects around the world and uses this expertise to deliver prompt design solutions. They offer various post-tensioning systems like bonded and unbonded tendons to provide optimized solutions for structural requirements. CCL aims to provide architectural freedom and reliability through post-tensioned slabs.
This document provides information on Flexco's Bolt Solid Plate fastener system for heavy-duty belt conveyor applications. It summarizes the key features and benefits of the Bolt Solid Plate fastener system, including its superior strength from compression of plates mounted above and below belts, deep belt carcass penetration without damage, and piloted bolts for easy installation. Installation guidelines and a selection guide are provided to help customers choose the appropriate fastener size and splice pattern for their conveyor belts and pulley diameters. Ordering information and installation tools are also listed.
PPS UK are exclusive distributors of Flexco products in West Africa - Process & Plant Sales Limited Tel: +44 1902 495 913 Email: james.wood@processandplant.co.uk
Ghana, Mali, Cote D'Ivoire, Burkina Faso, Mauritania, Senegal, Liberia, Togo, Sierra Leone etc.
The document provides an overview of prestressed concrete structures including:
- Definitions of prestressing where internal stresses counteract external loads.
- The key terminology used including tendons, anchorage, pretensioning vs post-tensioning.
- The materials used including cement, concrete, and steel types.
- The stages of loading and advantages of prestressing over reinforced concrete.
- Details of pretensioning and post-tensioning systems including equipment, processes, and differences between the two methods.
Prestressed concrete is concrete in which internal stresses are introduced to counteract external loads. Tendons are stretched elements that impart prestress, and anchorage devices enable the tendons to impart and maintain prestress. There are two main methods - pretensioning, where tendons are tensioned before concrete is cast, and post-tensioning, where tendons are tensioned against hardened concrete. Prestressed concrete uses high-strength materials like cement, concrete, and steel tendons or strands to achieve its compressive strength and durability advantages over reinforced concrete.
This document discusses methods of prestressing concrete, including pretensioning and post-tensioning. Pretensioning involves stressing steel tendons before concrete is poured around them. Post-tensioning involves stressing steel tendons inserted into voids in cured concrete using jacks. Both methods put the concrete in compression and improve its tensile strength. Common applications include building floors/roofs, bridges, and parking structures.
Post-tensioning is a technique for reinforcing concrete structures. The prestressing steel cables inside the sleeves or plastic ducts are positioned in the forms before placing the concrete. As the concrete gains strength, the cables are stressed to design forces before the application of the service load and are anchored att the outer edge region of the concrete.
This document discusses different types of long span roof structures including portal frame roofs. It describes the anatomy of a typical portal frame roof, which comprises columns, rafters, secondary steelwork like purlins and side rails, and cladding. Different types of portal frames are also discussed. The document further explains installation methods for metal decking on long span roofs and considers natural lighting and ventilation for industrial buildings.
Tall Structures
Usually structure or building having height more than 80m is considered as a tall structure.
Generally tall structure may be defined as one that because of its height it is affected by lateral.
Classification: 1. Multi storeyedresidential building.
2. Multi storeyedcommercial building.
3. Tall chimneys.
4. Transmission Towers
5. Cooling towers
Prestressed Concrete
•Prestressis defined as a method of applying pre-compression to control the stresses resulting due to external loads below the neutral axis of the beam tension developed due to external load which is more than the permissible limits of the plain concrete.
Demolition
•The action or process of destroying(demolishing)the building or other structures.
•In congested area, in particular, the quality of demolition technique becomes an essential element which determines the success of revitalization of city.
•In addition to efficiency in demolition, strategies must be adopted to avoid noise, vibration and dust which affect the surrounding environment and there must be efficient disposal of waste products
This document provides an introduction to prestressed concrete, including:
- Prestressing concrete involves applying an initial compressive load to counteract tensile stresses during use. Ancient examples include metal bands on wood.
- Prestressing provides advantages over reinforced concrete like reduced cracking, increased strength and stiffness, and suitability for precast construction.
- It describes prestressing materials, common systems like pre-tensioning and post-tensioning, and concepts in the analysis and design of prestressed concrete like stress conditions and load balancing.
This document provides information on various mechanical rebar splicing systems produced by Moment, including:
- Barbreak, JoinTec, Reverse Lock, and Positioning couplers, which join rebar using threaded connections and are designed to withstand breaking loads of at least 700 N/mm2.
- Details on the components, features, and installation procedures for each coupler type.
- The couplers exceed requirements of various international codes and standards and offer benefits like increased strength, reduced congestion, and easier installation compared to lap splicing.
This document provides information on various mechanical rebar splicing systems produced by Moment, including:
- Barbreak couplers which use tapered threads for easy alignment and achieve full strength with 4-5 turns.
- Jointec couplers which ensure full strength splicing through parallel threads and behave as continuous reinforcement.
- Reverse lock couplers which are designed for heavily congested areas and connect bent bars.
- Positioning couplers which are used when bars cannot rotate and comprise three components to connect non-rotating bars.
Technical specifications and installation procedures are provided for each coupler type. The couplers are designed to exceed requirements of international codes and provide alternatives to traditional lap splicing.
This document discusses practical aspects of pre-stressed concrete (PSC) construction. It explains that PSC uses the intrinsic properties of steel and concrete, with concrete good for compression and steel for tension. Reinforcement is still needed in PSC for shear transfer, crack control, and stress distribution. Proper detailing and positioning of prestressing cables and reinforcement is important. Common issues in PSC construction include honeycombing, cracking, and stresses exceeding design limits. Solutions involve modified forms, grouting, additional reinforcement, and adjusted cable profiles. Proper material handling, stressing sequences, and construction methods are essential for successful PSC projects.
We have designed & manufacture the Lubi Valves LBF series type of Butterfly Valves for General Utility Water applications as well as for HVAC applications.
Online train ticket booking system project.pdfKamal Acharya
Rail transport is one of the important modes of transport in India. Now a days we
see that there are railways that are present for the long as well as short distance
travelling which makes the life of the people easier. When compared to other
means of transport, a railway is the cheapest means of transport. The maintenance
of the railway database also plays a major role in the smooth running of this
system. The Online Train Ticket Management System will help in reserving the
tickets of the railways to travel from a particular source to the destination.
2. accredited specialists
Mega Prefab is a complete service provider of structural
precast and post-tensioned concrete.
We are involved thoroughly in all the phases of the
project. We will design, manufacture, deliver, and install
our products.
With more than 16 years of experience in the business,
we have optimized our structural elements to be efficient,
safe and low cost.
The post-tensioning accessories are manufactured
with the satisfaction of the quality control system
and conforming to the requirements of international
standards such as [PTI] and [BS 4447].
Mega Prefab post-tensioning systems have been
approved for use by:
• Government departments
• Local authorities
• Engineering consultancies
• Multinational construction companies and organizations
what is a post-tension slab?
Before a post-tension slab is poured, high-strength steel
strands or cables, called tendons, are laid in a tight grid.
These help support and give strength to the slab once the
concrete has been cured and they have been tensioned at
the proper pressure.
3. scope of services
Based on its extensive and proven experience in the
highly specialized area of post-tensioning construction,
Mega Prefab offers a comprehensive range of
professional services including:
• Consulting services and designs covering all aspects
of post-tensioned construction.
• Quality controlled post-tensioning Supply materials,
products and equipments.
• Project feasability study for post-tension application.
• Preliminary design and cost estimation.
• Final design and shop/working drawings.
• Complete supply and installation of
post-tensioning systems.
system features and products
Mega Prefab post tensioning systems’ significant
features and advantages:
• Wide selection of anchorage types.
• Products are provided with full range of tendon sizes
from single strand with up to 5 nos of 0.5”/0.6” strand.
[Bigger tendon sizes are also available upon request].
• Anchorage adaptable for both strand of 0.5” (12.5mm)
and 0.6” (15.7mm) according to standard ASTM A416
or BS 5896.
• Advanced stressing jacks equipped with automatic
stressing heads and power wedge seating devices.
• The systems available in any number of stressing
steps and sequences
4. advantages of
post-tensioned slab systems
Mega Prefab slabs bring unique architectural freedom
when compared to conventional building methods.
They allow increased spans to be achieved with thinner
concrete sections. By reducing the need for columns, the
structure becomes more efficient and functional.
The main advantages of post-tension slab over
conventional reinforced concrete slab, may be
summarized as follows:
• Increased clear spans
• Thinner slabs
• Lighter structures
• Reduced cracking & deflections
• Reduced story height
• Rapid construction
• Better water tightness
These advantages can result in significant savings in
overall costs. There are also some situations where
the height of the building is limited, in which the
reduced story height has allowed additional floors to be
constructed within the building envelope. The following
figures 1 and 2 on the right show the deflection of the slab
before the post-tension forces were applied. The finite
element analysis is done using Adapt Builder 2010.
bonded or unbonded tendons
Post-tensioned slab systems can be constructed using
either bonded or unbonded tendons. The relative merit of
the two techniques are subject to debate.
The following points may be in favor of each:
bONDED TENDONS
• Higher ultimate flexural strength
• Non-dependant on anchorage after grouting
• Localized damage effect
• Simple technique for demolishing or providing future
opening in slab
UNbONDED TENDONS
• Smaller diameter
• Provides greater lever arm
• Reduces friction losses
• Simplifies prefabrications of tendons
• Grouting not required
• Faster Construction
Figure 1:
Deflection before post-tension
Figure 2:
Deflection after post-tension
unbonded tendonsbonded tendons
5. single strand unbonded
tendon system
The single strand system is adapted only for unbonded
tendons. The strand is greased and PE coated for
corrosion protection as well as reducing friction. The
strand is gripped by a single strand anchorage type. To
provide for a corrosion protection system the anchorage
is encapsulated by a special plastic cap after the stressing
and the strand end has been cut.
ANCHORAGE COMPONENTS
• Pocket former
• Wedge
• Anchor plate casting
• Anchorage Bursting-Reinforcement
• P.E. connector
• Unbonded strand greased and P.E. coated
• Encapsulated plastic anchor cap
The same anchorage for stressing can be used as
intermediate stressing anchorage and dead end
anchorage. For dead end anchorage, the wedge is pre-
seated in the anchorage by applying nominal force to the
strand using the stressing Jack.
Alternatively a loop dead anchorage can be used in which
case the strand is formed in loop shape around the loop
bearing plate and stressing anchorage are used at the
stressing ends of the loop tendon.
A nominal reinforcing bar of 2T12 grades 40 is normally
provided behind the stressing anchorage to act as
bursting reinforcement in the anchorage zone.
single strand unbonded tendon system specifications
strand diameter 0.5” [12.5 mm] 0.6” [15.7 mm]
Number of strands 1 1
Type of anchorage SF 105 SF 106
Section per tendon (cm2
) 0.93 1.5
Stressing force at 0.75 U.T.S. (Tons) 13.0 20.9
Jack type V 16 V 24
anchorage dimensions (mm)
strand diameter a b
SF 105 100 60
SF 106 125 75
6. multistrand unbonded
tendon system
The multistrand flact duct systems are normally
adapted for bonded tendon. The strands are individually
gripped in one flat anchor head unit and transmit their
prestressing forces by mean of flat type anchor plate
casting unit. The strands are stressed individually by
mean of a mono strand jack. The strands are contained in
one flat duct which is made of corrugated galvanized or
non-galvanized metal.
To ensure corrosion protection and to give adequate bond
strength, the tendons are filled with suitable cement
grout mix after complete stressing of the strands.
ANCHORAGE COMPONENTS
• Pocket former
• Wedges
• Anchor head type SF
• Anchor plate casting type SF
• Grout vent
• Corrugated metal flat duct
• Anchorage bursting reinforcement
The same anchorage for stressing anchorage can be used
as dead end anchorage in which case the wedges are
preseated in the anchor head unit by applying nominal
force to the strand using the stressing jack.
Alternatively a bulb dead end anchorage can be used with
simpler solution and more cost effective. In this case each
strand is formed into a bulb shape by means of special
bulb forming jack.
Bursting reinforcement should be provided at the
anchorage zone for both stressing anchorage and dead
end anchorage type. It can be placed longitudinally or
transversally.
multistrand unbonded tendon system specifications
strand diameter 0.5” [12.5 mm] 0.6” [15.7 mm]
Number of strands
205
2
305
3
405
4
505
5
206
2
306
3
406
4
506
5
Anchorage head type SF 205 SF 305 SF 405 SF 505 SF 206 SF 306 SF 406 SF 506
Section per tendon (cm2
) 1.86 2.79 3.72 4.65 3.00 4.50 6.00 7.50
Ultimate tensile force per tendon.
Stressing force at 0.75 U.T.S. (Tons)
25.9 38.9 51.9 64.9 45.8 62.8 83.7 104.6
Flat duct inside dimension mm x mm
63.5 x 20
63.5 x 20
76.5 x 20
63.5 x 20
63.5 x 20
76.5 x 20
95.0 x 22
Jack type V 16 V 24
7. applications
The use of post-tensioned slab systems has been
consistently growing in the recent years.
Typical applications have been:
• Private residential housing
• Offices
• Car parks
• Shopping centers
• Hospitals
• Hotels and apartments
• Industrial buildings
• Transverse pre-stressing of bridge deck slabs.
chiah municipality
residential building
achrafieh 838
saadeh residential villa
amrosiyeh shopping center & offices
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煤炉代买
paypay商城
乐天二手
日本亚马逊
乐天新品
ZOZOTOWN
![accredited specialists
Mega Prefab is a complete service provider of structural
precast and post-tensioned concrete.
We are involved thoroughly in all the phases of the
project. We will design, manufacture, deliver, and install
our products.
With more than 16 years of experience in the business,
we have optimized our structural elements to be efficient,
safe and low cost.
The post-tensioning accessories are manufactured
with the satisfaction of the quality control system
and conforming to the requirements of international
standards such as [PTI] and [BS 4447].
Mega Prefab post-tensioning systems have been
approved for use by:
• Government departments
• Local authorities
• Engineering consultancies
• Multinational construction companies and organizations
what is a post-tension slab?
Before a post-tension slab is poured, high-strength steel
strands or cables, called tendons, are laid in a tight grid.
These help support and give strength to the slab once the
concrete has been cured and they have been tensioned at
the proper pressure.](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)