The document discusses guidelines for detailing reinforcement in concrete structures. It begins by defining detailing as the preparation of working drawings showing the size and location of reinforcement. Good detailing ensures reinforcement and concrete interact efficiently. The document then discusses sources of tension in concrete structures from various loading conditions like bending, shear, and connections. It provides equations from AS3600-2009 for calculating minimum development lengths for reinforcing bars to develop their yield strength based on bar size, concrete strength, and transverse reinforcement. It also discusses lap splice requirements. In summary, the document provides best practice guidelines for detailing reinforcement to efficiently resist loads and control cracking in concrete structures.
This document provides an analysis and design of a G+3 residential building. It includes details of the building such as dimensions, material properties, and load calculations. An equivalent static analysis is performed to calculate the seismic lateral loads at each floor level. The results of the structural analysis including bending moment and shear force diagrams are presented. Slab, beam, column and footing designs are to be covered in the thesis work according to the scope.
The document provides a 7 step process for modeling a structure in ETABS according to Eurocodes, including:
1) Specifying material properties for concrete.
2) Adding frame sections for columns and beams.
3) Defining slab and wall properties.
4) Specifying the response spectrum function.
5) Adding load cases.
6) Defining equivalent static analysis and load combinations.
7) Specifying the modal response spectrum analysis.
This document provides information about the design of a composite deck bridge. It includes an abstract describing the key components of a composite deck bridge. The introduction defines different bridge types. The main body describes the structural components of a composite deck bridge, including the RC slab, steel girders, and shear connectors. It outlines the design procedure and provides literature references. The conclusion indicates that site data will be collected and a composite deck bridge will be analyzed and designed using MIDAS software.
The document discusses the design of footings for structures. It begins by explaining that footings are needed to transfer structural loads from members made of materials like steel and concrete to the underlying soil. It then describes different types of shallow and deep foundations, including spread, strap, combined, and raft footings. The document provides details on designing isolated and combined footings to resist vertical loads and moments based on provisions in IS 456. It also discusses wall footings and combined footings that support multiple columns. In summary, the document covers the purpose of footings, various footing types, and design of isolated and combined footings.
The document discusses the balanced cantilever method of bridge construction. It begins by explaining that this method is used for bridges with spans between 50-250m, and involves attaching precast or cast-in-place segments in an alternating manner from each end of cantilevers supported by piers. This method is well-suited for irregular spans, congested sites, and environmentally sensitive areas. It also discusses advantages like determinacy and reduced cracking risks. The document then goes into detail about construction sequences, member proportioning, superstructure types, and analysis of a specific balanced cantilever bridge in Kochi, India.
ANALYSIS AND DESIGN OF G+4 RESIDENTIAL BUILDING contentsila vamsi krishna
This document outlines the process and methods used to analyze and design a multi-story residential building using STAAD Pro software. It includes chapters on software used, literature review of analysis methods, load calculations, design of building elements like beams, columns, slabs and footings. Load combinations are defined according to Indian standards. Material properties and design assumptions are provided. The document then describes the analysis and design of each building element and provides sample output diagrams from STAAD Pro.
Design of steel structure as per is 800(2007)ahsanrabbani
It does not offer resistance against rotation and also termed as a hinged or pinned connections.
It transfers only axial or shear forces and it is not designed for moment
It is generally connected by single bolt/rivet and therefore full rotation is allowed
This document provides an analysis and design of a G+3 residential building. It includes details of the building such as dimensions, material properties, and load calculations. An equivalent static analysis is performed to calculate the seismic lateral loads at each floor level. The results of the structural analysis including bending moment and shear force diagrams are presented. Slab, beam, column and footing designs are to be covered in the thesis work according to the scope.
The document provides a 7 step process for modeling a structure in ETABS according to Eurocodes, including:
1) Specifying material properties for concrete.
2) Adding frame sections for columns and beams.
3) Defining slab and wall properties.
4) Specifying the response spectrum function.
5) Adding load cases.
6) Defining equivalent static analysis and load combinations.
7) Specifying the modal response spectrum analysis.
This document provides information about the design of a composite deck bridge. It includes an abstract describing the key components of a composite deck bridge. The introduction defines different bridge types. The main body describes the structural components of a composite deck bridge, including the RC slab, steel girders, and shear connectors. It outlines the design procedure and provides literature references. The conclusion indicates that site data will be collected and a composite deck bridge will be analyzed and designed using MIDAS software.
The document discusses the design of footings for structures. It begins by explaining that footings are needed to transfer structural loads from members made of materials like steel and concrete to the underlying soil. It then describes different types of shallow and deep foundations, including spread, strap, combined, and raft footings. The document provides details on designing isolated and combined footings to resist vertical loads and moments based on provisions in IS 456. It also discusses wall footings and combined footings that support multiple columns. In summary, the document covers the purpose of footings, various footing types, and design of isolated and combined footings.
The document discusses the balanced cantilever method of bridge construction. It begins by explaining that this method is used for bridges with spans between 50-250m, and involves attaching precast or cast-in-place segments in an alternating manner from each end of cantilevers supported by piers. This method is well-suited for irregular spans, congested sites, and environmentally sensitive areas. It also discusses advantages like determinacy and reduced cracking risks. The document then goes into detail about construction sequences, member proportioning, superstructure types, and analysis of a specific balanced cantilever bridge in Kochi, India.
ANALYSIS AND DESIGN OF G+4 RESIDENTIAL BUILDING contentsila vamsi krishna
This document outlines the process and methods used to analyze and design a multi-story residential building using STAAD Pro software. It includes chapters on software used, literature review of analysis methods, load calculations, design of building elements like beams, columns, slabs and footings. Load combinations are defined according to Indian standards. Material properties and design assumptions are provided. The document then describes the analysis and design of each building element and provides sample output diagrams from STAAD Pro.
Design of steel structure as per is 800(2007)ahsanrabbani
It does not offer resistance against rotation and also termed as a hinged or pinned connections.
It transfers only axial or shear forces and it is not designed for moment
It is generally connected by single bolt/rivet and therefore full rotation is allowed
The document discusses structural steel construction, including the various methods used such as beam and column construction, long span construction, and wall bearing construction. It describes the common structural steel members like columns, beams, joists, and trusses that are erected and secured together using fastening systems like bolts and welds to form the structural framework. Details provided on erection plans guide the fabrication and installation of the different steel components.
Review paper on seismic responses of multistored rcc building with mass irreg...eSAT Journals
Abstract
From past earthquakes it is proved that many of structure are totally or partially damaged due to earthquake. So, it is necessary to determine seismic responses of such buildings. There are different techniques of seismic analysis of structure. Time history analysis is one of the important techniques for structural seismic analysis generally the evaluated structural response is non-linear in nature. For such type of analysis, a representative earthquake time history is required. In this project work seismic analysis of RCC buildings with mass irregularity at different floor level are carried out. Here for analysis different time histories have been used. This paper highlights the effect of mass irregularity on different floor in RCC buildings with time history and analysis is done by using ETABS software.
Keywords: Seismic Analysis, Time History Analysis, Base Shear, Storey Shear, Story Displacement.
This document is the Indian Standard (Part 1) for earthquake resistant design of structures. It provides general provisions and criteria for assessing earthquake hazards and designing buildings to resist earthquakes. Some key points:
- It defines seismic zones across India based on past earthquake intensities and establishes design response spectra for each zone.
- It provides minimum design forces for normal structures and notes that special structures may require more rigorous site-specific analysis.
- This revision includes changes such as defining design spectra to 6 seconds, specifying the same spectra for all building materials, including temporary structures, and provisions for irregular buildings and masonry infill walls.
- It establishes terminology used in earthquake engineering and references other relevant Indian Standards for
1. The document discusses the analysis of statically determinate structures. It describes how to idealize structures by representing joints as pinned or fixed connections.
2. The principle of superposition states that the effects of separate loads on a structure can be added to determine the total effects. This requires structures to behave linearly.
3. Statically determinate structures have as many equations of equilibrium as there are unknown internal forces. These equations can be written and solved to find member forces.
Workshop under the Capacity Building Programme of the Southern Road Connectivity Project / Expressway Connectivity Improvement Plan Project, March 2016
This document is the Indian Railway Standard Code of Practice for plain, reinforced and prestressed concrete for general bridge construction from 1997. It provides definitions for terminology used, specifies materials and workmanship for concrete, reinforcement and prestressing tendons. It defines loads, load combinations and requirements for limit state design. It provides recommendations for the design and construction of plain concrete, reinforced concrete and prestressed concrete bridges. The document covers topics such as concrete mix design, formwork, reinforcement, transportation and curing of concrete, prestressing, precast construction, and load testing.
This resource material is exclusively for the purpose of knowledge dissemination for the use of Civil engineering Fraternity, professionals & students.
This file contains state of art techniques adopted & practiced as per IS456 code provisions for analysis design & detailing of flat slab structural systems.
The presentation aims to provide clear,concise, technical details of flat slabs design.
The presentation deals with structural actions & behavior of flat slabs with visual representations obtained through finite element analysis.
The knowledge gained can be used for designing building structures frequently encountered in construction.
The presentation covers an important feature of slab systems supported on rigid & flexible support & clearly demarcates the minimum beam dimensions required to consider the supports to be either rigid or flexible.
The presentation alsoincludes clear technical drawings to highlight the importance of detailing w.r.t. rebar lay out - positioning & curtailment. Typical section drawing through middle & column strips are also included for visualizing rebar patterns in 3 -d views.
This presentation is an outcome of series of lectures for undergrad & grad students studying in civil engineering.
My next presentation would be on Analysis & design of deep beams.
Kindly mail me ( vvietcivil@gmail.com) your questions & valuable feedback.
The document discusses the design of staircases. It begins by defining key components of staircases like treads, risers, stringers, etc. It then describes different types of staircases such as straight, doglegged, and spiral. The document outlines considerations for designing staircases like dimensions, loads, and structural behavior. It provides steps for geometric design, load calculations, structural analysis, reinforcement design, and detailing of staircases. Numerical examples are also included to illustrate the design process.
The document discusses the use of computer programs like STAAD Pro for structural design and analysis. It explains how earlier structural designs were done manually using slide rules and calculators but computers now allow for more accurate analysis of frames, beams and modeling of entire buildings in 3D. STAAD Pro is highlighted as a powerful program that can be used for 3D modeling and analysis of multi-storied buildings, offering various analysis types and design capabilities for steel, concrete and other materials according to different codes.
This document discusses the behavior of composite slabs with profiled steel decking. It presents information on:
1) Composite slabs that use profiled steel sheets as permanent formwork and tensile reinforcement, allowing for 30% reduced concrete and lower structural weight.
2) The profiled steel decking used which is thin-walled, cold-formed sheets meeting ASTM and IS standards with a galvanized coating.
3) Three slabs - plain concrete, bar reinforced, and steel fiber reinforced - were tested for negative bending capacity, with the fiber reinforced slab showing over a 2.5x increase in load capacity compared to plain concrete.
This document provides an overview of the design of steel beams. It discusses various beam types and sections, loads on beams, design considerations for restrained and unrestrained beams. For restrained beams, it covers lateral restraint requirements, section classification, shear capacity, moment capacity under low and high shear, web bearing, buckling, and deflection checks. For unrestrained beams, it discusses lateral torsional buckling, moment and buckling resistance checks. Design procedures and equations for determining effective properties and capacities are also presented.
Peer review presentation for the strut and tie method as an analysis and design approach for the mat on piles foundations of the primary separation cell (vessel).
The Manual explains the concept of transferring the load from the super structure up to the soil throughout Piles, which has a capacity of (End bearing, and Skin friction). It illustrates the steps needed to produce a full and safe foundation for your Super Structure.
Calulation of deflection and crack width according to is 456 2000Vikas Mehta
This document discusses the calculation of crack width in reinforced concrete flexural members. It provides information on:
1) Crack width is calculated to satisfy serviceability limits and is only relevant for Type 3 pre-stressed concrete members that crack under service loads.
2) Crack width depends on factors like amount of pre-stress, tensile stress in bars, concrete cover thickness, bar diameter and spacing, member depth and location of neutral axis, bond strength, and concrete tensile strength.
3) The method of calculation involves determining the shortest distance from the surface to a bar and using equations involving member depth, neutral axis depth, average strain at the surface level. Permissible crack widths are specified depending on exposure
Modelling Building Frame with STAAD.Pro & ETABS - Rahul LeslieRahul Leslie
The document discusses modeling a reinforced concrete building frame using STAAD.Pro and ETABS software. It describes how to model the beams, columns, slabs, walls, stairs, and foundations. Initial member sizes are determined based on architectural requirements and design formulas. The building is modeled by framing the beams and columns. Loads like self-weight, floor loads, and wall loads are applied to the frame. Material properties of concrete are also specified. The document provides guidance on modeling the structural elements and applying loads in STAAD.Pro and ETABS to analyze the building frame.
Culvert Design 201 Structural Design, Durability & ApplicationsPath Marketing Inc.
Randy McDonald, Armtec Drainage’s Director of Engineering and Frank Klita, Senior Sales Representative build on the basics of culvert design covered in Culvert Design 101 and will focus in- depth on the structural design of culverts. Additionally, the presenters will review considerations and best practices for culvert installations.
You'll Learn:
Culvert types & applications
- Structural design of culverts and buried structures as per CHBDC (Canadian Highway Bridge Design Code) methods
- Installation best practices
- Review of applications across Canada
The document discusses STAAD.Pro tips and tricks, including:
1) Creating macros using OpenSTAAD and VBA to automate tasks like displaying maximum displacements from selected nodes.
2) Modeling stage construction by analyzing a structure built in two stages and combining the forces from each stage.
3) Other topics covered are foundations analysis and buckling analysis.
The document discusses the design requirements for lacing, battening, and column bases according to IS 800-2007. It provides details on:
- Two types of lacing systems - single and double
- Design requirements for lacing including angle of inclination, slenderness ratio, effective lacing length, bar width and thickness
- Design of battening including number of battens, spacing, thickness, effective depth, and transverse shear
- Minimum thickness requirements for rectangular slab column bases
It also provides an example problem demonstrating the design of a slab base foundation for a column.
This document provides an overview of the design of beams and one-way slabs for flexure, shear, and torsion according to IS 456. It discusses key concepts like requirements for flexural reinforcement, minimum and maximum reinforcement limits, clear cover, deflection control, and selection of member sizes. The document also includes a worked example showing the step-by-step design of a rectangular reinforced concrete beam for flexure. Design checks are performed to check for strength and deflection requirements. Modules for the course will cover analysis and design of beams, one-way slabs, and reinforcement detailing in accordance with limit state design principles and code specifications.
The document discusses structural steel construction, including the various methods used such as beam and column construction, long span construction, and wall bearing construction. It describes the common structural steel members like columns, beams, joists, and trusses that are erected and secured together using fastening systems like bolts and welds to form the structural framework. Details provided on erection plans guide the fabrication and installation of the different steel components.
Review paper on seismic responses of multistored rcc building with mass irreg...eSAT Journals
Abstract
From past earthquakes it is proved that many of structure are totally or partially damaged due to earthquake. So, it is necessary to determine seismic responses of such buildings. There are different techniques of seismic analysis of structure. Time history analysis is one of the important techniques for structural seismic analysis generally the evaluated structural response is non-linear in nature. For such type of analysis, a representative earthquake time history is required. In this project work seismic analysis of RCC buildings with mass irregularity at different floor level are carried out. Here for analysis different time histories have been used. This paper highlights the effect of mass irregularity on different floor in RCC buildings with time history and analysis is done by using ETABS software.
Keywords: Seismic Analysis, Time History Analysis, Base Shear, Storey Shear, Story Displacement.
This document is the Indian Standard (Part 1) for earthquake resistant design of structures. It provides general provisions and criteria for assessing earthquake hazards and designing buildings to resist earthquakes. Some key points:
- It defines seismic zones across India based on past earthquake intensities and establishes design response spectra for each zone.
- It provides minimum design forces for normal structures and notes that special structures may require more rigorous site-specific analysis.
- This revision includes changes such as defining design spectra to 6 seconds, specifying the same spectra for all building materials, including temporary structures, and provisions for irregular buildings and masonry infill walls.
- It establishes terminology used in earthquake engineering and references other relevant Indian Standards for
1. The document discusses the analysis of statically determinate structures. It describes how to idealize structures by representing joints as pinned or fixed connections.
2. The principle of superposition states that the effects of separate loads on a structure can be added to determine the total effects. This requires structures to behave linearly.
3. Statically determinate structures have as many equations of equilibrium as there are unknown internal forces. These equations can be written and solved to find member forces.
Workshop under the Capacity Building Programme of the Southern Road Connectivity Project / Expressway Connectivity Improvement Plan Project, March 2016
This document is the Indian Railway Standard Code of Practice for plain, reinforced and prestressed concrete for general bridge construction from 1997. It provides definitions for terminology used, specifies materials and workmanship for concrete, reinforcement and prestressing tendons. It defines loads, load combinations and requirements for limit state design. It provides recommendations for the design and construction of plain concrete, reinforced concrete and prestressed concrete bridges. The document covers topics such as concrete mix design, formwork, reinforcement, transportation and curing of concrete, prestressing, precast construction, and load testing.
This resource material is exclusively for the purpose of knowledge dissemination for the use of Civil engineering Fraternity, professionals & students.
This file contains state of art techniques adopted & practiced as per IS456 code provisions for analysis design & detailing of flat slab structural systems.
The presentation aims to provide clear,concise, technical details of flat slabs design.
The presentation deals with structural actions & behavior of flat slabs with visual representations obtained through finite element analysis.
The knowledge gained can be used for designing building structures frequently encountered in construction.
The presentation covers an important feature of slab systems supported on rigid & flexible support & clearly demarcates the minimum beam dimensions required to consider the supports to be either rigid or flexible.
The presentation alsoincludes clear technical drawings to highlight the importance of detailing w.r.t. rebar lay out - positioning & curtailment. Typical section drawing through middle & column strips are also included for visualizing rebar patterns in 3 -d views.
This presentation is an outcome of series of lectures for undergrad & grad students studying in civil engineering.
My next presentation would be on Analysis & design of deep beams.
Kindly mail me ( vvietcivil@gmail.com) your questions & valuable feedback.
The document discusses the design of staircases. It begins by defining key components of staircases like treads, risers, stringers, etc. It then describes different types of staircases such as straight, doglegged, and spiral. The document outlines considerations for designing staircases like dimensions, loads, and structural behavior. It provides steps for geometric design, load calculations, structural analysis, reinforcement design, and detailing of staircases. Numerical examples are also included to illustrate the design process.
The document discusses the use of computer programs like STAAD Pro for structural design and analysis. It explains how earlier structural designs were done manually using slide rules and calculators but computers now allow for more accurate analysis of frames, beams and modeling of entire buildings in 3D. STAAD Pro is highlighted as a powerful program that can be used for 3D modeling and analysis of multi-storied buildings, offering various analysis types and design capabilities for steel, concrete and other materials according to different codes.
This document discusses the behavior of composite slabs with profiled steel decking. It presents information on:
1) Composite slabs that use profiled steel sheets as permanent formwork and tensile reinforcement, allowing for 30% reduced concrete and lower structural weight.
2) The profiled steel decking used which is thin-walled, cold-formed sheets meeting ASTM and IS standards with a galvanized coating.
3) Three slabs - plain concrete, bar reinforced, and steel fiber reinforced - were tested for negative bending capacity, with the fiber reinforced slab showing over a 2.5x increase in load capacity compared to plain concrete.
This document provides an overview of the design of steel beams. It discusses various beam types and sections, loads on beams, design considerations for restrained and unrestrained beams. For restrained beams, it covers lateral restraint requirements, section classification, shear capacity, moment capacity under low and high shear, web bearing, buckling, and deflection checks. For unrestrained beams, it discusses lateral torsional buckling, moment and buckling resistance checks. Design procedures and equations for determining effective properties and capacities are also presented.
Peer review presentation for the strut and tie method as an analysis and design approach for the mat on piles foundations of the primary separation cell (vessel).
The Manual explains the concept of transferring the load from the super structure up to the soil throughout Piles, which has a capacity of (End bearing, and Skin friction). It illustrates the steps needed to produce a full and safe foundation for your Super Structure.
Calulation of deflection and crack width according to is 456 2000Vikas Mehta
This document discusses the calculation of crack width in reinforced concrete flexural members. It provides information on:
1) Crack width is calculated to satisfy serviceability limits and is only relevant for Type 3 pre-stressed concrete members that crack under service loads.
2) Crack width depends on factors like amount of pre-stress, tensile stress in bars, concrete cover thickness, bar diameter and spacing, member depth and location of neutral axis, bond strength, and concrete tensile strength.
3) The method of calculation involves determining the shortest distance from the surface to a bar and using equations involving member depth, neutral axis depth, average strain at the surface level. Permissible crack widths are specified depending on exposure
Modelling Building Frame with STAAD.Pro & ETABS - Rahul LeslieRahul Leslie
The document discusses modeling a reinforced concrete building frame using STAAD.Pro and ETABS software. It describes how to model the beams, columns, slabs, walls, stairs, and foundations. Initial member sizes are determined based on architectural requirements and design formulas. The building is modeled by framing the beams and columns. Loads like self-weight, floor loads, and wall loads are applied to the frame. Material properties of concrete are also specified. The document provides guidance on modeling the structural elements and applying loads in STAAD.Pro and ETABS to analyze the building frame.
Culvert Design 201 Structural Design, Durability & ApplicationsPath Marketing Inc.
Randy McDonald, Armtec Drainage’s Director of Engineering and Frank Klita, Senior Sales Representative build on the basics of culvert design covered in Culvert Design 101 and will focus in- depth on the structural design of culverts. Additionally, the presenters will review considerations and best practices for culvert installations.
You'll Learn:
Culvert types & applications
- Structural design of culverts and buried structures as per CHBDC (Canadian Highway Bridge Design Code) methods
- Installation best practices
- Review of applications across Canada
The document discusses STAAD.Pro tips and tricks, including:
1) Creating macros using OpenSTAAD and VBA to automate tasks like displaying maximum displacements from selected nodes.
2) Modeling stage construction by analyzing a structure built in two stages and combining the forces from each stage.
3) Other topics covered are foundations analysis and buckling analysis.
The document discusses the design requirements for lacing, battening, and column bases according to IS 800-2007. It provides details on:
- Two types of lacing systems - single and double
- Design requirements for lacing including angle of inclination, slenderness ratio, effective lacing length, bar width and thickness
- Design of battening including number of battens, spacing, thickness, effective depth, and transverse shear
- Minimum thickness requirements for rectangular slab column bases
It also provides an example problem demonstrating the design of a slab base foundation for a column.
This document provides an overview of the design of beams and one-way slabs for flexure, shear, and torsion according to IS 456. It discusses key concepts like requirements for flexural reinforcement, minimum and maximum reinforcement limits, clear cover, deflection control, and selection of member sizes. The document also includes a worked example showing the step-by-step design of a rectangular reinforced concrete beam for flexure. Design checks are performed to check for strength and deflection requirements. Modules for the course will cover analysis and design of beams, one-way slabs, and reinforcement detailing in accordance with limit state design principles and code specifications.
1. The document discusses the design of one-way reinforced concrete slabs according to Indian code IS 456:2000.
2. It defines one-way slabs as edge supported slabs spanning in one direction with a ratio of long to short span greater than or equal to 2.
3. The main considerations for slab design discussed are effective span, deflection control, reinforcement requirements including minimum area, maximum bar diameter and cover, and load calculations.
Design of column base plates anchor boltKhaled Eid
This document discusses the design of column base plates and steel anchorage to concrete. It covers base plate materials and design for different load cases including axial, moment, and shear loads. It also discusses anchor rod types, materials, and design for tension and shear loading based on calculations of the steel and concrete breakout strengths according to building codes.
1. The panel size is 5m x 7m without drop or column head.
2. The width of the column strip is calculated as 0.25x7m = 1.75m on each side of the column.
3. The required reinforcement is calculated for bending moments in the column strip and middle strip along the longer and shorter spans based on the loading and design parameters. The reinforcement details are shown in diagrams.
This document discusses the design of column base plates and steel anchorage to concrete. It provides an introduction to base plates and anchor rods, including materials and design considerations. It then covers the design of base plates for different load cases such as axial load, axial load plus moment, and axial load plus shear. Finally, it discusses the design of anchor rods for tension and shear loading based on the requirements in the ACI 318 code. The design procedures aim to ensure adequate load transfer from the steel column to the concrete foundation.
This document discusses the design of reinforced concrete deep beams. It defines deep beams as having a span/depth ratio less than 2 or a continuous beam ratio less than 2.5. Deep beams behave differently than elementary beam theory due to non-linear stress distributions. Their behavior depends on loading type and cracking typically occurs between one-third to one-half of the ultimate load. Design considerations include checking for minimum thickness, flexural design, shear design, and anchorage of tension reinforcement.
This document provides notation, materials, and design methods for masonry structures. It discusses reinforced and unreinforced masonry design based on allowable stress and strength/LRFD approaches. Key points include:
- Notation used in masonry design is defined, along with materials like masonry units, mortar, and grout.
- Reinforced masonry design uses steel reinforcement to resist tension while masonry resists compression based on equilibrium. Design is checked against allowable stresses.
- Columns must be reinforced and have ties. Allowable axial loads depend on factors like slenderness ratio and reinforcement.
- Examples demonstrate checking unreinforced wall capacity against loads and determining required
There are three main steps to designing a column splice:
1. Determine loads on the splice from axial, bending and shear forces. For axial loads, splices are designed to carry 50% of the load for machined ends or 100% for non-machined ends.
2. Design the splice plates to resist the loads using the yield stress as the design strength. Plate size is calculated based on load and stress.
3. Determine the number and size of bolts required based on the plate load capacity and bolt strengths in shear or bearing. Splice widths match the column and minimum plate thickness is 6mm.
This presentation is on design of welded and riveted connections in steel structures. in this presentation we learn briefly about these connections and design terminology about these connections.
This document discusses tension members in structural engineering. It defines tension members as linear members that experience axial forces that elongate or stretch the member. Examples given include ropes, ties in trusses, suspenders in bridges. The document discusses the types of cross-sections used for tension members like angles, channels, rods. It also discusses the calculation of net effective sectional area and provides examples. Other topics covered include types of failures in tension members, design strength calculations, limiting slenderness ratios, tension splices, and lug angles.
This document provides details and requirements for reinforcement in concrete structures. It discusses standard hooks used for reinforcement, minimum diameters for bar bending, surface conditions of reinforcement, placement of reinforcement, tolerances, spacing limits, bundled bars, tendons and ducts, concrete protection, headed shear and stud reinforcement, corrosive environments, column reinforcement including lateral ties and spirals, lateral reinforcement for beams, and requirements for structural integrity.
This document discusses ductile detailing of reinforced concrete (RC) frames according to Indian standards. It explains that detailing involves translating the structural design into the final structure through reinforcement drawings. Good detailing ensures reinforcement and concrete interact efficiently. Key aspects of ductile detailing covered include requirements for beams, columns, and beam-column joints to improve ductility and seismic performance. Specific provisions are presented for longitudinal and shear reinforcement in beams and columns, as well as confining reinforcement and lap splices. The importance of cover and stirrup spacing is also discussed.
This document provides information on analysis and design of reinforced concrete beams. It discusses key concepts such as modular ratio, neutral axis, stress diagrams, and types of reinforcement. It also defines under-reinforced, balanced, and over-reinforced beam sections. Several examples are provided to illustrate determination of neutral axis depth, moment of resistance, steel percentage, and stresses in concrete and steel reinforcement. Design aspects like maximum load capacity are also explained through examples.
DSR chap4 shear and bond pdf.pptxxxxxxxxxxxxxxxxxxxxxxADITYAPILLAI29
Shear reinforcement is required in concrete beams when the shear stresses exceed the shear strength of the concrete. Shear reinforcement takes the form of vertical stirrups or bent-up bars from the longitudinal reinforcement. The design of shear reinforcement involves calculating the shear force, nominal shear stress, shear strength of the concrete, and determining the amount and spacing of shear reinforcement needed. Proper development length of the longitudinal bars is also important to ensure adequate bond between the steel and concrete.
This document provides an overview of the design of rectangular reinforced concrete beams that are singly or doubly reinforced. It defines key assumptions in the design process including plane sections remaining plane after bending. It also covers evaluation of design parameters such as moment factors, strength reduction factors, and balanced reinforcement ratios. The design procedures for singly and doubly reinforced beams are described including checking crack width for singly reinforced beams. Figures are also provided to illustrate concepts such as stress distributions and the components of a doubly reinforced beam.
This document discusses concepts related to the design of concrete beams including:
1. It introduces concepts like bending, shear, tension and compression as they relate to beam design.
2. It provides formulas for calculating reactions, shear forces, and bending moments in simply supported beams under different loading conditions.
3. It explains concepts like the neutral axis, stress blocks, and strain diagrams that are important to beam design.
4. It discusses factors that influence the strength of beams like the moment of inertia and reinforcement ratio.
5. It compares working stress and limit state methods of design.
rectangular and section analysis in bending and shearqueripan
The document discusses the design of reinforced concrete beams for bending and shear. It covers the analysis of singly and doubly reinforced rectangular beam sections. Key points covered include the concept of neutral axis, under-reinforced and over-reinforced sections, design of bending reinforcement, design of shear reinforcement including link spacing, and deflection criteria. Worked examples are provided to demonstrate the design of bending and shear reinforcement for rectangular beams.
This document provides a summary of reinforced concrete columns (RCC columns). It defines a column and describes different types of columns based on reinforcement and length. Short columns are less than 12 times the minimum thickness, while long columns are greater than 12 times the thickness. The document outlines preliminary sizing of columns and the functions of tie/spiral reinforcement. It includes design equations for axially loaded columns in working stress design (WSD) and ultimate stress design (USD). Two sample problems are worked through demonstrating column design using both methods.
This document provides an overview of the design of reinforced concrete flexural members. Some key points include:
- Concrete will crack once it reaches its tensile strength of around 400 psi, while steel stress will be around 4000 psi.
- Design must consider serviceability limits like crack width and deflection, as well as providing adequate strength.
- Strain and stress diagrams are presented, showing cracked concrete and steel stresses and strains.
- Equations are given for calculating steel area, moment capacity, and reinforcement ratios. Reinforcement ratios should be less than the balanced ratio to prevent concrete crushing before steel yields.
- Minimum beam depths are provided to avoid requiring deflection calculations for preliminary design.
Similar to Div_Syd_detailing_of_reinforcement_in_concrete_structures.pdf (20)
Data Communication and Computer Networks Management System Project Report.pdfKamal Acharya
Networking is a telecommunications network that allows computers to exchange data. In
computer networks, networked computing devices pass data to each other along data
connections. Data is transferred in the form of packets. The connections between nodes are
established using either cable media or wireless media.
This study Examines the Effectiveness of Talent Procurement through the Imple...DharmaBanothu
In the world with high technology and fast
forward mindset recruiters are walking/showing interest
towards E-Recruitment. Present most of the HRs of
many companies are choosing E-Recruitment as the best
choice for recruitment. E-Recruitment is being done
through many online platforms like Linkedin, Naukri,
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Recruitment has gone through next level by using
Artificial Intelligence too.
Key Words : Talent Management, Talent Acquisition , E-
Recruitment , Artificial Intelligence Introduction
Effectiveness of Talent Acquisition through E-
Recruitment in this topic we will discuss about 4important
and interlinked topics which are
Sri Guru Hargobind Ji - Bandi Chor Guru.pdfBalvir Singh
Sri Guru Hargobind Ji (19 June 1595 - 3 March 1644) is revered as the Sixth Nanak.
• On 25 May 1606 Guru Arjan nominated his son Sri Hargobind Ji as his successor. Shortly
afterwards, Guru Arjan was arrested, tortured and killed by order of the Mogul Emperor
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• Guru Hargobind's succession ceremony took place on 24 June 1606. He was barely
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• He had a long tenure as Guru, lasting 37 years, 9 months and 3 days
Sachpazis_Consolidation Settlement Calculation Program-The Python Code and th...Dr.Costas Sachpazis
Consolidation Settlement Calculation Program-The Python Code
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Covid Management System Project Report.pdfKamal Acharya
CoVID-19 sprang up in Wuhan China in November 2019 and was declared a pandemic by the in January 2020 World Health Organization (WHO). Like the Spanish flu of 1918 that claimed millions of lives, the COVID-19 has caused the demise of thousands with China, Italy, Spain, USA and India having the highest statistics on infection and mortality rates. Regardless of existing sophisticated technologies and medical science, the spread has continued to surge high. With this COVID-19 Management System, organizations can respond virtually to the COVID-19 pandemic and protect, educate and care for citizens in the community in a quick and effective manner. This comprehensive solution not only helps in containing the virus but also proactively empowers both citizens and care providers to minimize the spread of the virus through targeted strategies and education.
1. THE CIVIL & STRUCTURAL ENGINEERING PANEL
THE CIVIL & STRUCTURAL ENGINEERING PANEL
ENGINEERS AUSTRALIA SYDNEY DIVISION
ENGINEERS AUSTRALIA SYDNEY DIVISION
28 August 2012
Detailing of Reinforcement
Detailing of Reinforcement
in Concrete Structures
in Concrete Structures
R.I. Gilbert
R.I. Gilbert
2. ¾
¾ Detailing
Detailing is often considered to be the
is often considered to be the preparation of working
preparation of working
drawings
drawings showing the size and location of the reinforcement in a
showing the size and location of the reinforcement in a
concrete structure.
concrete structure.
¾
¾ Detailing
Detailing involves the
involves the communication
communication of the engineer
of the engineer’
’s design to the
s design to the
contractors who build the structure. It
contractors who build the structure. It involves the translation of a
involves the translation of a
good structural design from the computer or calculation pad into
good structural design from the computer or calculation pad into the
the
final structure.
final structure.
¾
¾ Good detailing ensures that
Good detailing ensures that reinforcement
reinforcement
and concrete interact efficiently
and concrete interact efficiently to provide
to provide
satisfactory
satisfactory behaviour
behaviour throughout the
throughout the
complete range of loading.
complete range of loading.
¾
¾ In this seminar, guidelines for
In this seminar, guidelines for successful
successful
detailing
detailing in structural elements and
in structural elements and
connections are outlined.
connections are outlined.
Introduction
Introduction:
:
3. ¾ The detailing requirements of a reinforcement bar depend on the
reasons for its inclusion in the structure.
Reasons include:
1. To carry internal tensile forces, thereby imparting strength
and ductility;
2. To control flexural cracking;
3. To control direct tension cracking in restrained structures;
4. To carry compressive forces;
5. To provide restraint to bars in compression;
6. To provide confinement to concrete in compression;
7. To limit long‐term deformation;
8. To provide protection against spalling; and
9. To provide temporary support for other reinforcement during
construction.
4. Guiding principles:
¾ Determine location and direction of all internal forces (i.e.
establish a load path that satisfies equilibrium);
¾ Use adequately anchored reinforcement wherever a tensile
force is required for equilibrium;
¾ Use only ductile reinforcement (Class N or better) when the
reinforcement is required for strength;
¾ Never rely on the concrete’s ability to carry tension (it may not
exist);
¾ Include adequate quantities of reinforcement for crack control;
¾ Ensure steel details are practical and that steel can be fixed and
concrete can be satisfactorily placed and compacted around
complex details with adequate cover; and
¾ Ensure details are economical.
5. Sources of tension:
1. Tension caused by bending (and axial tension):
Positive bending
Negative bending
Axial tension
Flexural tension cracks
Flexural tension cracks
Direct tension cracks
6. Sources of tension:
2. Tension caused by load reversals:
Cantilever beam or slab
Simple beam or slab
Impact and rebound loading
7. Sources of tension (ctd):
3. Tension caused by shear and torsion:
C
C T
T
Shear
Tension carried by stirrups
Flexure‐shear cracks
8. Sources of tension (ctd):
4. Tension near the supports of beams:
The longitudinal tension at the support is greater than indicated
by the bending moment diagram.
The tensile force at the bottom of the inclined crack is equal to
the compressive force at the top of the crack.
9. Sources of tension (ctd):
Lst
AS3600‐2009 (8.1.10.4):
Sufficient bottom steel must be
anchored for a length (Lst) past the
mid‐point of the bearing to develop
a tensile force of V*cot θv/φ (plus any
additional force arising from restraint)
This requirement is deemed to be satisfied if either
≥ ½ Ast is extended past the face of the support by ≥ 12db ; or
≥ ⅓ Ast is extended past the face of the support by ≥ 12db + D/2
where Ast is the tensile steel area required at mid‐span
10. Sources of tension (ctd):
5. Tension within the supports of beams and slabs:
Cracking due to inadequate
slip joint between slab and
supporting brickwall
11. Sources of tension (ctd):
6. Tension within connections:
Hanger
reinf. to
carry
tension
Primary girder
Compression struts
Reaction from secondary beam
applied here
Secondary
beam
M
M
C
C
T
T
M
M
(a) Internal forces (b) Crack pattern
2 T
13. Sources of tension (ctd):
8. Tension caused by directional changes of internal forces:
(a)
T
T
T
R
stirrups
(b)
Lsy.t
(c)
C C
R Potential crack in web
Asv at spacing s
14. Sources of tension (ctd):
8. Tension caused by directional changes of internal forces:
(a)
T
T
T
R
stirrups
(b)
Lsy.t
(c)
Asv at spacing s
C
T
C
T
rm
qt
Ast
m
sy
st
m
t
r
f
A
r
T
q =
= m
sy
vy
st
sv
t
vy
sv
r
f
f
A
A
q
f
A
s .
.
=
=
Transverse tension: Required stirrup spacing:
15. Splitting failures around developing bars.
F F F
β
T
F F F
Tensile stresses
Splittin
Atr Atr
Splitting cracks
a) Forces exerted by concrete on a deformed bar (b) Tensile stresses in concrete
at a tensile anchorage
(c) Horizontal splitting due (d) Vertical splitting due to (e) Splitting (bond) failure
insufficient bar spacing. insufficient cover at a lapped splice.
Anchorage of deformed bars is tension:
16. Lsy.t
φ fb
As fsy
b
sy
b
t
sy
f
f
d
L
φ
4
. ≥
• For a reinforcement bar to reach its yield stress at a critical
cross‐section, a minimum length of reinforcing bar (an
anchorage) is required on either side of the section.
• AS3600‐2009 specifies a minimum length, called the development
length, Lsy.t, over which a straight bar in tension must be embedded in
the concrete in order to develop the yield stress.
• An average design ultimate bond stress φfb is assumed at the interface
between the concrete and the reinforcing bar (φ = 0.6).
• φfb depends on ‐ type and condition of reinforcing bar; strength
and compaction of concrete; concrete cover;
bar spacing; transverse reinforcement;
transverse pressure (or tension).
17. • The basic development length, Lsy.tb, is
where k1 = 1.3 for a horizontal bar with > 300mm of concrete cast
below it and k1 = 1.0 for all other bars;
k2 = (132 – db)/100 ;
k3= 1.0 ‐ 0.15(cd – db)/db (but 0.7≤ k3 ≤1.0)
cd is the smaller of the concrete cover to the bar or half
the clear distance to the next parallel bar;
f′c shall not be taken to exceed 65 MPa
AS3600‐2009: (§13.1.2.2)
b
d
k1
29
≥
c
2
b
sy
3
1
sy.tb
5
.
0
f
k
d
f
k
k
L
′
=
19. • The development length Lsy.t may be taken as the basic
development length or may be refined to include the beneficial
effects of confinements by transverse steel or transverse pressure
and is
where k4 = 1 ‐ Kλ (but 0.7≤ k4 ≤ 1.0); and
k5 = 1.0 ‐ 0.04ρp (but 0.7≤ k5 ≤1.0);
AS3600-2009 ctd (§13.1.2.3)
sy.tb
5
4
sy.t L
k
k
L =
20. FIGURE 13.1.2.3(B) VALUES OF K FOR BEAMS AND SLABS
K = 0.1 K = 0.05 K = 0
sy.tb
5
4
sy.t L
k
k
L =
k4 = 1 - Kλ
where
λ = (ΣAtr − ΣAtr.min)/As ;
ΣAtr = cross-sectional area of the transverse reinforcement along the development
length Lsy.t
ΣAtr.min = cross-sectional area of the minimum transverse reinforcement, which may
be taken as 0.25As for beams and 0 for slabs
As = cross-sectional area of a single bar of diameter db being anchored
K = is a factor that accounts for the position of the bars being anchored
relative to the transverse reinforcement, with values given below:
AS3600-2009 ctd (§13.1.2.3)
21. • The development length Lst to develop a stress σst lower than fsy :
When calculating σst don’t forget to include the strength reduction factor
(φ = 0.8). If T* is the design ultimate tensile force in the reinforcement
caused by the factored design loads, then:
and therefore
AS3600-2009 ctd (§13.1.2.3)
b
sy
st
sy.t
st 12d
f
L
L ≥
=
σ
st
st
st
st
*
*
A
T
A
T
φ
σ
σ
φ
≥
≤
22. • The development length of a deformed bar with a standard hook
or cog:
AS3600-2009 ctd (§13.1.2.3)
(a) Standard hook (180° bend) (b) Standard hook (135° bend).
0.5Lsy.t
≥ 4db or 70mm
did
X
0.5Lsy.t
did /2
X
(c) Standard cog (90° bend).
0.5Lsy.t
did /2
X
A A
A
X X
X
did 0.5did
0.5Lsy.t
0.5Lsy.t
0.5Lsy.t
≥ 4db or 70mm
(a) Standard hook (180° bend) (b) Standard hook (135° bend)
(c) Standard cog (90° bend)
23. WORKED EXAMPLE:
Consider the minimum development length required for the two
terminated 28 mm diameter bottom bars in the beam shown below.
Take fsy = 500 MPa; f’c = 32 MPa; cover to the 28 mm bars c = 40 mm;
and the clear spacing between the bottom bars a = 60 mm.
The cross‐sectional area of one N28 bar is As = 620 mm2 and with N12
stirrups at 150 mm centres, Atr = 110 mm2.
AS3600-2009
P P
Lsy.t
12mm stirrups at 150mm ctrs
Two terminated bars
A
A
Elevation Section A-A
Lsy.t + d
Lsy.t + D
24. For bottom bars: k1 = 1.0;
For 28 mm diameter bars: k2 = (132 – 28)/100 = 1.04;
The concrete confinement dimension, cd = a/2 = 30 mm, and therefore
k3 = 1.0 – 0.15(30 – 28)/28 = 0.99
The basic development length is therefore
The minimum number of stirrups that can be located within the basic
development length is 7. Therefore, ΣAtr = 7 x 110 = 770 mm2.
Taking ΣAtr.min = 0.25As = 155 mm2, the parameter
λ = (770 – 155)/620 = 0.99
Worked Example ctd (§13.1.2.3)
)
29
(
mm
1178
32
04
.
1
28
500
99
.
0
0
.
1
5
.
0
1
sy.tb b
d
k
L >
=
×
×
×
×
=
c
2
b
sy
3
1
sy.tb
5
.
0
f
k
d
f
k
k
L
′
=
25. From Figure 13.1.2B, K = 0.05 (as it is the two interior bars that are being
developed) and therefore
It is assumed that in this location the transverse pressure perpendicular to
the anchored bar (ρp) is zero, and hence k5 = 1.0.
From Eq. 13.1.2.3:
Worked Example ctd (§13.1.2.3)
sy.tb
5
4
sy.t L
k
k
L =
95
.
0
99
.
0
05
.
0
0
.
1
0
.
1
4 =
×
−
=
−
= λ
K
k
.
mm
1120
1178
0
.
1
95
.
0
.
5
4
. =
×
×
=
= bt
sy
t
sy L
k
k
L
The strength of the beam must be checked at the point where the two
bars are terminated (ie. at Lsy.t+d from the constant moment region)
26. Lapped Splices for bars in tension (13.2.2
Lapped Splices for bars in tension (13.2.2 –
– AS3600
AS3600‐
‐2009):
2009):
PLANAR VIEW
sL a
db sb
Lsy.t.lap
Note: For the purposes of determining cd, the
dimension a shall be taken equal to (sL-db)
irrespective of the value of sb.
cd, = min (a/2, ccrit )
(i) 100% of bars spliced (no staggered splice)
cd, = min (a/2, ccrit )
(ii) 50% staggered splices
PLANAR VIEW
Lsy.t.lap
≥ 0.3Lsy.t.lap
a
sL
sb
Note: For the purposes of determining cd, the
dimension a shall be taken equal to 2sL
irrespective of the value of sb.
(a/2, c )
(a/2, c )
cd = min (a/2, c)
(i) 100% of bars spliced (no staggered splices)
(ii) 50% staggered splices
cd = min (a/2, c)
27. Lapped Splices for bars in tension:
Lapped Splices for bars in tension:
AS3600‐2009: §13.2.2
sy.t
7
sy.t.lap L
k
L = b
d
k1
29
≥
k7 shall be taken as 1.25, unless As provided is greater than As required
and no more than one‐half of the tensile reinforcement at the section is
spliced, in which case k7 = 1.
In narrow elements or members (such as beam webs and columns), the
tensile lap length (Lsy.t.lap) shall be not less than the larger of k7 Lsy.t and
Lsy.t +1.5sb, where sb is the clear distance between bars of the lapped
splice as shown in Figure 8.15.
28. Consider the lapped splice requirements for N12 bars at 200 mm centres in the
bottom of a slab. Cover = 20 mm. Concrete strength = 25 MPa.
AS3600‐2009:
ACI 318‐08: (Refined – Clause 12.2.3)
b
e
t
d
lap d
f
f
L
c
y
1
.
2
3
.
1
3
.
1
′
=
=
λ
ψ
ψ
l
12
25
0
.
1
1
.
2
0
.
1
0
.
1
500
3
.
1 ×
×
×
×
×
×
=
b
d
9
.
61
mm
743 =
=
b
b
tr
b
s
e
t
d
lap d
d
K
c
f
f
L
)
(
1
.
1
3
.
1
3
.
1
c
y
+
′
=
=
λ
ψ
ψ
ψ
l
12
)
12
0
26
(
25
0
.
1
1
.
1
8
.
0
0
.
1
0
.
1
500
3
.
1 ×
+
×
×
×
×
×
×
=
b
d
7
.
43
mm
524 =
=
ACI 318‐08: (Simplified – Clause 12.2.2)
c
2
b
sy
3
1
sy.tb
sy.t.lap
5
.
0
25
.
1
f
k
d
f
k
k
L
L
′
=
=
25
2
.
1
12
500
90
.
0
0
.
1
5
.
0
25
.
1
×
×
×
×
×
×
=
b
d
9
.
46
mm
563 =
=
)
2001
3600
AS
in
7
.
30
mm
369
.
.
(
−
= b
d
f
c
29. Detailing of beams:
Anchorage of longitudinal reinforcement:
Favorable anchorage
Elevation Section
Unfavorable anchorage Transverse tension
Possible
cracks
Normal
pressure
C
C
T T
T
When bottom reinforcement is
terminated away from the support,
the diagonal compression in the web
improves the anchorage.
30. Current wording:
“The design for flexural strength and detailing of flexural reinforcement
and pretensioned tendons at termination shall be extended from the
theoretical cut‐off point, or debonding point, by a length of 1.0D + Lsy.t, or
1.0D + Lpt, where D is the member depth at the theoretical cut‐off point or
theoretical debonding point”
‐ Problem 1: The wording does not make sense
‐ Problem 2: The rule is incorrect – a bar does not have to develop
its yield stress at the theoretical cut‐off point
Amended wording:
“Where flexural reinforcement and pretensioned tendons are to be
terminated, the bars or tendons shall be extended from the theoretical cut‐
off point, or theoretical debonding point, by a length of at least 1.0D + Lst,
or 1.0D + Lpt, respectively, where D is the member depth at the theoretical
cut‐off point or theoretical debonding point”
AS3600-2009 Clause 8.1.10.1
31. Detailing of beams (ctd):
tilted anchorage near horizontal anchorage diagonal compression
Reaction pressure Reaction pressure
Sections and Elevations
Plan
The transverse tension that may cause splitting in
the plane of a hooked anchorage at a support can
be overcome at a beam support simply by tilting the
hook and exposing it to the normal reaction pressure.
32. Detailing of beams (ctd):
If the bearing length at a support is small and close to the free end of a
member, a sliding shear failure along a steep inclined crack may occur.
Additional small diameter bars may be required perpendicular to the
potential failure plane
Potential failure
surface
Inclined clamping
bars
33. Detailing of beams (ctd):
Where the length available for anchorage is small, mechanical
anchorages in the form of welded cross‐bars or end plates may be used.
Common in precast elements, corbels, brackets and at other support
points.
welded
cross‐bar
end plate
(a) (b) (c)
recessed
angle
34. Detailing of beams (ctd):
In short span members, where load is carried to the support by arch
action, it is essential that all bottom reinforcement (the tie of the arch)
is fully developed at each support. Closely spaced transverse stirrups
can be used to improve anchorage of the tie reinforcement.
Compressive strut
Tie
Do NOT terminate any bottom bars
Binding
reinforcement
Anchorage is
critical
Member
Centreline
35. Detailing of beams (ctd):
Concentrating top steel at a support in a beam within the web can lead
to crack control problems in the adjacent slab (Leonhardt et al.)
0
10
20
30
40
50
60
70
0 100 200 300 400 500
Load (kN)
Crack
width
(0.01
mm))
As = 1030 mm2
As = 1020 mm2
36. Detailing of beams (ctd):
Anchorage of Stirrups:
¾ Tension in stirrup is more or less constant over height of vertical leg.
Therefore, all points on vertical leg must be fully developed
¾ Stirrup anchorages should be located in the compressive zone and
be shown on the structural drawings.
¾ The area of shear reinforcement required at a particular cross‐
section should be provided for a distance D from that cross‐section
in the direction of decreasing shear (AS3600‐2009 – Clause 8.2.12.3).
Compressive top chord (concrete)
Vertical ties (stirrups)
Inclined web struts
(concrete)
Tensile bottom chord (Ast)
37. Detailing of beams (ctd):
Types of Stirrups:
(a) Incorrect
Inadequate anchorage
A 90° cog is ineffective if the
cover concrete is lost
Tensile lapped
splice
(c) Satisfactory
Compressive side
Tensile side
(b) Undesirable (but satisfactory)
In regions where ductility is required,
the open stirrups (commonly used in
post‐tensioned beams) do not confine the
compressive concrete
38. Detailing of beams (ctd):
Types of Stirrups:
cracks
Ts
Cd
Compression strut
Cd
Ts
Ts
Rigid Flexible
¾ Multi‐leg stirrups should be used in members with wide webs to
avoid the undesirable distribution of diagonal compression shown
¾ Multi‐leg sturrups better control shear cracking and help maintain
shear transfer though aggregate interlock
39. Detailing of beams (ctd):
Types of Stirrups:
¾ Multi‐leg stirrups are also far better for controlling the
longitudinal splitting cracks (known as dowel cracks) that
precipitate bond failure of the longitudinal bars in the shear span.
¾ Often this critical shear crack occurs where bottom bars are
terminated in the shear span. Additional shear reinforcement may
be required in this region (Clause 8.1.10.5 – AS3600‐2009).
Dowel crack
40. Detailing of beams (ctd):
Crack control provided by shear reinforcement (Leonhardt et al):
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 200 400 600
Load P (kN)
Maximum
crack
width
(mm)
1
2
3
4
(mm)
41. Detailing of beams (ctd):
Support and Loading Points:
¾ When the support is at the soffit of a beam or slab, the diagonal
compression passes directly into the support as shown
¾ When the support is at the top of the beam, the diagonal compression
must be carried back up to the support via an internal tie.
¾ It is essential that adequately anchored reinforcement be included
to act as the tension tie and the reinforcement must be anchored
into the support
(a) Support under
support
Internal
tie
(b) Support over
42. Detailing of beams (ctd):
Slab supported by upturned beam:
(a) Incorrect detail
¾ The vertical component of the diagonal compression in the slab
(i.e. the reaction from the slab) must be carried in tension up to the
top of the upturned beam.
¾ Don’t rely on the unreinforced surface to carry this tension
Unreinforced
surface
(b) Correct detail
43. Detailing of beams (ctd):
Beam‐to‐beam connection:
¾ The area of additional
suspension reinforcement
is
Primary
girder
R*
suspension
reinforcement
(a) Section
Secondary
beam
Compression strut in secondary beam
Suspension
reinforcement
(b) Primary girder ‐ Elevation
Stirrups
for shear
(c) Primary girder – Truss analogy
R*
sy
sr
f
R
A
φ
*
=
44. Detailing of beams (ctd):
Beam‐to‐beam connection:
¾ When a load is applied to the underside of a reinforced concrete
beam, some device must be used to transfer this hanging load to the
top of the beam
(b) Internal rods
45. Detailing of beams (ctd):
Half‐Joint or dapped‐end joint:
(a) Half joint
(b) Strut and tie model Reinforcement detail
Hairpin reinforcement
Suspension reinforcement
(c) Alternative strut and tie model Reinforcement detail
46. •
• Excessive cracking
Excessive cracking due to
due to restrained deformation
restrained deformation or
or external
external
loads
loads is a common cause of damage in reinforced concrete
is a common cause of damage in reinforced concrete
structures.
structures.
•
• Excessive cracking
Excessive cracking in the hardened concrete can be avoided
in the hardened concrete can be avoided
by including sufficient reinforcement at sufficien
by including sufficient reinforcement at sufficiently close
tly close
spacings
spacings.
.
•
• Shrinkage
Shrinkage causes a
causes a gradual widening of existing cracks
gradual widening of existing cracks and
and
time
time‐
‐dependent cracking
dependent cracking in previously uncracked regions.
in previously uncracked regions.
Detailing for Crack Control
Detailing for Crack Control
•
• The
The minimum quantities of reinforcement
minimum quantities of reinforcement specified for crack
specified for crack
control in AS3600 may not be what is actually requ
control in AS3600 may not be what is actually required in all
ired in all
circumstances.
circumstances.
47. •
• The
The width of a crack
width of a crack depends on
depends on
‐
‐ the quantity, orientation and distribution of the
the quantity, orientation and distribution of the
reinforcing steel crossing the crack;
reinforcing steel crossing the crack;
‐
‐ concrete cover and member size;
concrete cover and member size;
‐
‐ the bond between concrete and reinforcement
the bond between concrete and reinforcement
in the vicinity of the crack;
in the vicinity of the crack;
‐
‐ the deformation characteristics of concrete; and
the deformation characteristics of concrete; and
‐
‐ the shrinkage strain (and therefore the time after
the shrinkage strain (and therefore the time after
crack formation).
crack formation).
‐
‐ the cause of the crack
the cause of the crack
‐
‐ the degree of restraint
the degree of restraint
•
• Often significantly more reinforcement than the minimum
specified amount is required.
48. Crack spacing, s, varies between
0.5d and 1.5d and depends on
- steel area and distribution
- cover
Crack width, w, depends on
- steel stress
- bar diameter and bar spacing
- cover
- adjacent crack spacings
and the average crack spacing
decreases with time due to
shrinkage
and increases with time due to
shrinkage
d
Maximum crack widths
increase with time by a factor
of between 2 and 4
Service loads
Flexural cracks
Flexural cracking:
49. Simplified Approach for Flexural Crack Control in AS3600‐2009
(Clause 8.6.1 and 9.4.1):
For reinforced concrete beams and slabs, cracking is deemed to be controlled
(crack widths will be less than 0.3 mm) if each of the following is satisfied:
(a) the quantity of tensile reinforcement in a beam or slab provides an
ultimate strength at least 20% higher than the cracking moment
calculated assuming σcs = 0;
(b) the distance from the side or soffit of the member to the centre of the
nearest longitudinal bar shall not exceed 100 mm;
(c) The centre‐to‐centre spacing of bars near a tension face of a beam or
slab shall not exceed 300 mm for a beam and the lesser of two times
the slab thickness and 300 mm for a slab.
(d) The stress in the tensile steel is less than a limiting value (as follows):
50. Simplified Approach for Flexural Crack Control in AS3600‐2009
(Clause 8.6.1 and 9.4.1): Ctd
For members subject primarily to flexure, the calculated steel stress caused
by the serviceability design moment shall not exceed the larger of the
maximum steel stresses given in Tables 8.6.1(A) and 8.6.1(B) for beams
and Tables 9.4.1(A) and 9.4.1(B) for slabs.
Table 8.6.1(A): Maximum steel stress for Table 8.6.1(B): Maximum steel stress for
tension or flexure in r.c. beams. flexure in r.c. beams.
Nominal bar
diameter
(mm)
Maximum steel
stress
(MPa)
Centre-to-centre
spacing
(mm)
Maximum steel
stress
(MPa)
10 360 50 360
12 330 100 320
16 280 150 280
20 240 200 240
24 210 250 200
28 185 300 160
32 160
36 140
40 120
51. Simplified Approach for Flexural Crack Control in AS3600‐2009
(Clause 8.6.1 and 9.4.1): Ctd
For members subject primarily to tension, the calculated steel stress caused
by the serviceability design actions shall not exceed the maximum steel
stresses given in Tables 8.6.1(A) for beams and Tables 9.4.1(A) for slabs.
Table 9.4.1(A): Maximum steel stress for Table 9.4.1(B): Maximum steel stress for
flexure in r.c. slabs. flexure in r.c. slabs.
Maximum steel stress (MPa)
for overall depth Ds (mm)
Nominal bar
diameter
(mm) ≤ 300 > 300
Centre-to-centre
spacing
(mm)
Maximum steel
stress
(MPa)
6 375 450 50 360
8 345 400 100 320
10 320 360 150 280
12 300 330 200 240
16 265 280 250 200
20 240 300 160
24 210
52. Restrained Shrinkage Cracking in Slabs
Restrained Shrinkage Cracking in Slabs:
:
™
™ Provided that
Provided that bonded reinforcement
bonded reinforcement at
at reasonable spacing
reasonable spacing crosses
crosses
the crack and that the member does not
the crack and that the member does not deflect excessively, flexural
deflect excessively, flexural
cracks are usually well controlled in reinforced concrete
cracks are usually well controlled in reinforced concrete beams and
beams and
slabs.
slabs.
™
™ In contrast,
In contrast, direct tension cracks
direct tension cracks due to restrained shrinkage and
due to restrained shrinkage and
temperature changes frequently lead to serviceability prob
temperature changes frequently lead to serviceability problems,
lems,
particularly in regions of low moment.
particularly in regions of low moment.
™
™ Such cracks usually extend completely through the member and a
Such cracks usually extend completely through the member and are
re
more parallel sided than flexural cracks.
more parallel sided than flexural cracks.
™
™ If uncontrolled, these cracks can become very wide and lead to
If uncontrolled, these cracks can become very wide and lead to
waterproofing and corrosion problems.
waterproofing and corrosion problems.
™
™ They can also disrupt the integrity and the structural action
They can also disrupt the integrity and the structural action of the slab.
of the slab.
53. Flexural cracks
One‐way floor slab supported on beams
Full depth restrained shrinkage cracks
¾ Usually more steel is required to control the restrained shrinkage
cracks than is required to control the flexural cracks and provide
adequate strength.
The slab is restrained by beams and shrinkage induces tension
in the slab in the direction of the beams
54. Restrained Shrinkage Cracking in Slabs
Restrained Shrinkage Cracking in Slabs Ctd
Ctd:
:
™
™ In the primary direction, shrinkage will cause small increases in the
widths of the many fine flexural cracks and may cause additional
flexure type cracks in the previously uncracked regions.
™ However, in the secondary direction, which is in effect a direct
tension situation, shrinkage generally causes a few widely spaced
cracks which penetrate completely through the slab.
™ If the amount of reinforcement crossing a direct tension crack is
small, yielding of the steel will occur and a wide, unserviceable crack
will result. To avoid this eventuality, the minimum steel ratio, ρmin is
where . For 32 MPa concrete, ρmin = 0.0034.
™ For a serviceable crack width, significantly more steel than this is
required.
sy
ct
st
f
f
d
b
A 2
.
1
min
min =
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
=
ρ
'
25
.
0 c
ct f
f =
55. Crack Control in Slabs
Crack Control in Slabs –
–AS3600
AS3600‐
‐2009:
2009:
™ Where the ends of a slab are restrained and the slab is not free to
expand or contract in the secondary direction, the minimum area of
reinforcement in the restrained direction is given by either Eq. 1a,
1b or 1c, as appropriate (see below).
™ For a slab fully enclosed within a building except for a brief period of
weather exposure during construction:
(i) where a strong degree of control over cracking is required:
(ii) where a moderate degree of control over cracking is required:
(iii) where a minor degree of control over cracking is required:
( ) )
a
2
.
9
(
10
)
5
.
2
0
.
6
( 3
min
−
×
−
= D
b
A cp
s σ
( ) )
b
2
.
9
(
10
)
5
.
2
5
.
3
( 3
min
−
×
−
= D
b
A cp
s σ
( ) )
c
2
.
9
(
10
)
5
.
2
75
.
1
( 3
min
−
×
−
= D
b
A cp
s σ
(1a)
(1b)
(1c)
56. ™ For all other slab surface conditions in Exposure Classification A1
and for exposure classification A2, Eq. 1a applies where a strong
degree of control over cracking is required for appearance or where
cracks may reflect through finishes
and Eq. 1b applies where a moderate degree of control over cracking
is required and where cracks are inconsequential or hidden from view.
™ For Exposure Classifications B1, B2, C1 and C2, Eq. 1a always applies.
™ The minimum steel area given by Eq. 1c is appropriate in an
unrestrained direction where the slab is free to expand or contract.
™ In the primary direction of a one‐way slab or in each direction of a
two‐way slab, the minimum quantity of reinforcement is the greater of
the minimum quantity required for the strength limit state or 75% of
the minimum area required by Eqs. 1a, 1b or 1c, as appropriate.
( ) )
a
2
.
9
(
10
)
5
.
2
0
.
6
( 3
min
−
×
−
= D
b
A cp
s σ
( ) )
b
2
.
9
(
10
)
5
.
2
5
.
3
( 3
min
−
×
−
= D
b
A cp
s σ
(1a)
(1b)
57. Consider a slab restrained at each end.
With time, restrained shrinkage cracks occur at roughly regular centres
depending on the amount of reinforcement:
(a) Portion of restrained member after all cracking
(c) Steel stress after all shrinkage cracking
(b) Average concrete stress after all shrinkage
58. Typical values:
Consider a 140 mm thick, 4m long slab fully‐restrained at both ends
and symmetrically reinforced with N12 bars at 250 mm centres top
and bottom. Hence, As= 900 mm2/m and ρ = As/Ac = 0.00643.
L = 4 m
140 mm
For 25 MPa concrete with a final shrinkage strain of 0.0007 and
typical material properties, a shrinkage cracking analysis of this
restrained slab indicates 4 or 5 full depth cracks within the 4 m
length with the maximum final crack width about 0.3 mm.
59. If p = 0 :
p = As/Ac
2.8 mm
one large
unserviceable
crack
If p = 0.0035
≈ 0.6 – 0.7 mm
about three
unserviceable
(?) cracks
If p = 0.006
≈ 0.3 – 0.4 mm
Four or five
serviceable
(?) cracks
4 m
140 mm
60. Detailing of columns:
Lapped compressive splices:
Normal
fitment
spacing, s
Additional
fitment spacing,
s’ < 4c
R
Additional fitments at
compressive splice
Tension at
cranked bars
Unsatisfactory tension
splice in thin wall
61. Detailing of columns:
Typical tie arrangements in columns:
AS3600‐2009 requirements for restraining single longitudinal bars in columns:
(i) Every corner bar;
(ii) All bars ‐ where bars are spaced at centres > 150 mm;
(iii) At least every alternate bar ‐ where bar centres ≤ 150mm.
For bundled bars – each bundle must be restrained.
All longitudinal bars in
these columns are restrained
at
(i) a bend in a fitment of 135°
or less; or
(ii) at a fitment hooks with
included angle of 135° or
less, as shown.
62. Detailing of columns:
Minimum bar diameters for fitments (AS3600‐2009):
6
10
12
16
12
Single bars up to 20
Single bars 24 to 28
Single bars 28 to 36
Single bar 40
Bundled bars
Minimum bar diameter
for fitment and helix (mm)
Longitudinal bar diameter
(mm)
Maximum spacing of fitments (AS3600‐2009):
The spacing of fitments (or the pitch of a helix) should not exceed the
smaller of:
Dc and 15db for single bars
0.5Dc and 7.5db for bundled bars
64. Detailing of Beam‐column Connections:
Knee Connections under “Opening” Moment:
M
M
C
C
T
T
T
2
M
M
(a) Internal forces (b) Crack pattern
M
M
M
M
(a) Unsatisfactory (b) Unsatisfactory
M
M
(c) Potentially satisfactory
f
sy
sy
st
f
sy
sv
f
f
A
f
T
A
.
.
2
2
φ
φ
=
=
65. Detailing of Beam‐column Connections:
Knee Connections under “Opening” Moment – Suggested detail:
Diagonal flexural bars
Diagonal
stirrups
M
M
66. Detailing of Beam‐column Connections:
Knee Connections under “Closing” Moment:
M
M
T
T
C
C
T
2
M
M
(a) Internal forces (b) Crack pattern
M
M
(a) Wall or slab connection (when p ≤ fct.f /fsy) (b) Beam to column knee connection
M
M
67. Detailing of Beam‐column Connections:
Three‐member connections:
(a) Internal forces (b) Crack pattern
High bond stress
Poor anchorage
conditions
68. Detailing of Beam‐column Connections:
Three‐member connections – Reinforcement detail:
Larger diameter bar to distribute
bearing stresses in bend
Ties to carry diagonal tension, to
control vertical splitting and to
confine the concrete core
70. Detailing of Corbels:
(a) Strut-and-tie action (b) Reinforcement detail (c) Welded primary steel
Crack control steel
Main or primary tensile
reinforcement
Cross bar to
distribute bearing
stresses in bend
T
C
ℓweld=¾db
ℓweld=¾db
tweld=db/2
tweld=db/2
db
db
Primary tensile reinforcement
Anchor
bar
(d) Satisfactory weld details (17)
Welded
anchor bar
(see Fig 8.46d)
Primary
tension steel
71. Design of Corbels:
T
C
θ
d D
a
V*
Figure 8.47
≥ d/2
)
8
.
0
(
tan
*
=
=
= φ
φ
θ
sy
s f
A
V
T
θ
φ tan
*
sy
s
f
V
A =
∴
)
6
.
0
(
9
.
0 =
′
= st
c
c
s
st
u
st A
f
C φ
β
φ
φ
Tie:
Strut:
)
0
.
1
3
.
0
(
cot
66
.
0
0
.
1
1
2
≤
≤
+
= s
s β
θ
β
2
/
s
h A
A ≥
Park and Paulay suggest that a good first estimate of corbel dimensions
is obtained from:
and ACI318‐08 suggests
c
w f
d
b
V ′
≤ 56
.
0
/
*
sy
c
w
s
sy
c f
f
d
b
A
f
f
d
a /
2
.
0
/
/
04
.
0
and
0
.
1
/ ′
≤
≤
′
≤
72. Design of Corbels:
d D
400
mm
D/2
200
mm
T*
C*
(b)
θ
V*
dc=400/sinθ
= 541 mm
d D
400
mm
V*
= 500kN
D/2 200
mm
(a)
bw = 300 mm
MPa
32
=
′
c
f MPa
500
=
sy
f Cover = 30 mm
Bearing plate = 200 x 300 mm in plan
dc = 200/sinθ
= 270 mm
73. Design of Corbels:
From :
56
.
0
/
*
c
w f
d
b
V ′
≤ mm
526
32
56
.
0
300
10
500 3
=
×
×
×
≥
d
With D = d + cover + 0.5 bar dia and assuming 20 mm diameter bars,
take D = 570 mm and therefore d = 530 mm.
From the geometry:
and
Try 4 N20 bars (1240 mm2)
Now
The strut efficiency factor:
and
400
)
90
tan(
100
tan
θ
θ
−
−
=
d o
7
.
47
=
∴ θ
2
3
mm
1138
7
.
47
tan
500
8
.
0
10
500
=
×
×
×
=
s
A
OK
/
122
.
0
0078
.
0
/ ∴
′
=
= sy
c
w
s f
f
d
b
A
65
.
0
cot
66
.
0
0
.
1
1
2
=
+
=
θ
βs
kN
911
81150
32
9
.
0
65
.
0
6
.
0 =
×
×
×
×
=
u
stC
φ
OK
kN
743
cos
/
*
* ∴
=
=
> θ
V
C
74. Design of Corbels:
285
285
4 N20
3 N12
stirrups
ELEVATION
PLAN
285
285
4 N20
3 N12
Stirrups
N28 welded
cross-bar
ELEVATION
PLAN
N24 cross-bar
(welded to N20s)
75. JOINTS IN STRUCTURES:
Joints are introduced into concrete structures for two main reasons:
1) As stopping places in the concreting operation. The location of
these construction joints depends on the size and production
capacity of the construction site and work force;
2) To accommodate deformation (expansion, contraction, rotation,
settlement) without local distress or loss of integrity of the
structure. Such joints include:
control joints (contraction joints);
expansion joints;
structural joints (such as hinges, pin and roller joints);
shrinkage strips; and
isolation joints.
The location of these joints depends on the anticipated
movements of the structure during its lifetime and the resulting
effects on structural behaviour.
76. Construction Joints:
Steel dowels to improve shear strength
1st
pour 2nd
pour
Waterstop where water tightness is required
(a) Butt joint (b) Keyed joint
(c) Doweled joint
77. Control Joints (or Contraction Joints):
Debond dowel to ensure free contraction
Saw cut > 0.2 t and 20 mm ≈0.75 t
Discontinue every second bar if necessary so that p < 0.002
(a) Saw-cut joint in slab on ground (b) Wall (t < 200 mm)
(d) Wall (t ≥ 200 mm) (c) Doweled joint
t
≈0.75 t
Discontinue every second bar if necessary so that p < 0.002
78. Typical control joint locations:
Control joint locations
(a) Wall elevation
(b) Balcony plan