This document discusses reinforcement development length, which is the minimum length required for bond stress to develop between steel reinforcement and concrete. It provides formulas to calculate development length based on factors like bar diameter, yield strength, concrete strength, and transverse reinforcement. The development length must be sufficient to prevent bar pullout under load. Standards like ACI Code specify minimum development lengths empirically related to these factors to ensure the bond can develop adequately.
multistorey building design by sap and autocadRazes Dhakal
This document summarizes the structural analysis and design of a 7-storey commercial building in Bhaktapur, Nepal. The project members modeled the building in SAP 2000 and designed the structural components including slabs, beams, columns, staircases, basement walls, lifts, and raft foundation. The structural design followed codes IS456, IS875, IS1893, and considered seismic and gravity loads. The building has RCC framing with raft foundation. Structural elements were designed for strength and serviceability requirements then detailed.
This document discusses guidelines for anchorage and development length of reinforcement in concrete structures. It addresses factors that modify development length for tension and compression reinforcement. It also covers standard hook development lengths and requirements for reinforcement layout at points of maximum moment, zero moment, and where reinforcement is stopped in a tension zone. Critical points on reinforcement are defined based on bar layout and code requirements.
Factors to consider in foundation designMushtaq Zaib
Factors to consider in foundation design include: footing depth and spacing, location of spread footings, soil pressures, erosion risks for structures near water, corrosion protection, water table fluctuations, and properties of soil types like sand, silt, loess, clays, and expansive soils. Designs must account for frost depth, moisture changes, unsuitable subsurface materials, adjacent existing structures, net versus gross pressures, predicted scour depths, corrosion risks, drainage, and consolidation settlements.
information on types of beams, different methods to calculate beam stress, design for shear, analysis for SRB flexure, design for flexure, Design procedure for doubly reinforced beam,
This document discusses bearing capacity of shallow foundations. It defines bearing capacity as the ability of soil to safely carry pressure without shear failure. Terzaghi's bearing capacity theory from 1943 is described, including his assumptions of three soil zones and equations for calculating ultimate bearing capacity. The effects of foundation shape, inclined loads, soil type (clay vs. sand), and water table are explained. Settlement analysis is also important to determine allowable bearing capacity. An example problem demonstrates calculating the net allowable bearing capacity of a footing in clay.
This document discusses earthwork and provides definitions and classifications for different types of soils and rocks encountered during excavation. It describes the measurement and payment terms for earthwork, including lead, lift, and disposal. Safety protocols for excavation works and protections for existing structures and utilities are also outlined. The document provides classifications for different types of soils, rocks, and hard rocks. It describes the process for site clearance, setting out profiles, and taking ground measurements before starting earthwork. Blasting procedures for hard rocks are also summarized.
Hi everyone thanks for you to see our report again, and our report contains every single information about deep foundation just like advantages and disadvantages and types and here again just like the shallow foundation report we compared both with each other.
And from this link you read about shallow foundation
https://www.slideshare.net/mobile/AliRizgar/shallow-foundation-full-information
And from this email you can ask any thing to us
Alirizgar234@gmail.com
This document provides details on the design of staircases, including:
1. It describes the typical components of a staircase like flights, landings, risers, treads, nosings, waist slabs, and soffits.
2. It discusses different types of staircases like straight, quarter turn, dog-legged, open well, spiral and helicoidal.
3. It classifies staircases structurally into those with stair slabs spanning transversely or longitudinally and provides examples of each type.
4. It provides an example calculation for the design of a waist slab spanning longitudinally, including loading, bending moment calculation, reinforcement design and checks.
multistorey building design by sap and autocadRazes Dhakal
This document summarizes the structural analysis and design of a 7-storey commercial building in Bhaktapur, Nepal. The project members modeled the building in SAP 2000 and designed the structural components including slabs, beams, columns, staircases, basement walls, lifts, and raft foundation. The structural design followed codes IS456, IS875, IS1893, and considered seismic and gravity loads. The building has RCC framing with raft foundation. Structural elements were designed for strength and serviceability requirements then detailed.
This document discusses guidelines for anchorage and development length of reinforcement in concrete structures. It addresses factors that modify development length for tension and compression reinforcement. It also covers standard hook development lengths and requirements for reinforcement layout at points of maximum moment, zero moment, and where reinforcement is stopped in a tension zone. Critical points on reinforcement are defined based on bar layout and code requirements.
Factors to consider in foundation designMushtaq Zaib
Factors to consider in foundation design include: footing depth and spacing, location of spread footings, soil pressures, erosion risks for structures near water, corrosion protection, water table fluctuations, and properties of soil types like sand, silt, loess, clays, and expansive soils. Designs must account for frost depth, moisture changes, unsuitable subsurface materials, adjacent existing structures, net versus gross pressures, predicted scour depths, corrosion risks, drainage, and consolidation settlements.
information on types of beams, different methods to calculate beam stress, design for shear, analysis for SRB flexure, design for flexure, Design procedure for doubly reinforced beam,
This document discusses bearing capacity of shallow foundations. It defines bearing capacity as the ability of soil to safely carry pressure without shear failure. Terzaghi's bearing capacity theory from 1943 is described, including his assumptions of three soil zones and equations for calculating ultimate bearing capacity. The effects of foundation shape, inclined loads, soil type (clay vs. sand), and water table are explained. Settlement analysis is also important to determine allowable bearing capacity. An example problem demonstrates calculating the net allowable bearing capacity of a footing in clay.
This document discusses earthwork and provides definitions and classifications for different types of soils and rocks encountered during excavation. It describes the measurement and payment terms for earthwork, including lead, lift, and disposal. Safety protocols for excavation works and protections for existing structures and utilities are also outlined. The document provides classifications for different types of soils, rocks, and hard rocks. It describes the process for site clearance, setting out profiles, and taking ground measurements before starting earthwork. Blasting procedures for hard rocks are also summarized.
Hi everyone thanks for you to see our report again, and our report contains every single information about deep foundation just like advantages and disadvantages and types and here again just like the shallow foundation report we compared both with each other.
And from this link you read about shallow foundation
https://www.slideshare.net/mobile/AliRizgar/shallow-foundation-full-information
And from this email you can ask any thing to us
Alirizgar234@gmail.com
This document provides details on the design of staircases, including:
1. It describes the typical components of a staircase like flights, landings, risers, treads, nosings, waist slabs, and soffits.
2. It discusses different types of staircases like straight, quarter turn, dog-legged, open well, spiral and helicoidal.
3. It classifies staircases structurally into those with stair slabs spanning transversely or longitudinally and provides examples of each type.
4. It provides an example calculation for the design of a waist slab spanning longitudinally, including loading, bending moment calculation, reinforcement design and checks.
Structural engineering involves relating physical forces to structural elements that resist them. Analysis determines forces in each element of a defined structure, while design configures elements to resist known forces. The process iterates between analysis and design until complete. Structures resist vertical and horizontal loads, and include large items like bridges as well as everyday items. Structural design requires data on the structure type, site conditions like soil properties, and loading conditions from dead and live loads, wind, and earthquakes as defined by codes. Design methods are selected based on local practices.
This document discusses shear force and bending moment diagrams. It explains the concepts of shear force and bending moment and how to draw shear force and bending moment diagrams for beams subjected to different types of loading. The document is intended as a guide for students to understand shear force and bending moment diagrams.
This document discusses using quality assurance tests to identify defects in large diameter bored piles for two construction projects. For the first project, pile load tests, integrity tests, and coring identified necking, bulging, and a weak pile toe, likely due to a "soft toe" condition. The pile capacities were reduced and additional piles were added. For the second project, integrity and load tests found impedance reductions and doubtful pile integrity below certain depths. Load capacities were de-rated based on the test results. The conclusion emphasizes the importance of a comprehensive quality assurance program to ensure foundation safety and performance.
This document summarizes different types of piles used in construction foundations including friction piles, end bearing piles, sheet piles, load piles, and more. It describes how piles can be made of timber, steel, concrete, or composites. The document also outlines various pile driving methods such as drop hammers, single/double acting steam hammers, diesel hammers, vibratory drivers, and safety procedures for pile driving operations.
This document provides design aids for reinforced concrete structures based on Indian Standard IS: 456-1978 Code of Practice for Plain and Reinforced Concrete.
The design aids cover material strength and stress-strain relationships, flexural members, compression members, shear and torsion, development length and anchorage, working stress design, deflection calculation, and general tables. Charts and tables are provided for preliminary and final design of beams, slabs, and columns. Assumptions made in developing the design aids are explained. An example illustrates the use of the design aids. Important points regarding the use and limitations of the charts and tables are noted.
The design aids were prepared based on examination of international handbooks and consultation with Indian
This document is the sixth edition of the National Structural Code of the Philippines (NSCP) Volume I, which provides requirements for designing buildings, towers, and other vertical structures. It was published in 2010 by the Association of Structural Engineers of the Philippines. The code contains chapters on minimum design loads, materials, and other topics to guide structural design in compliance with the latest standards. The foreword expresses pride in the publication and updates to the code to regulate structural design for safety.
This contains methods of exploration in rock. How the rock samplers are taken. Quality of rock samples and its reporting. Along with the laboratory tests conducting on these rock samples.
The document describes a student project that aims to prepare design aids in the form of interaction curves for column design. The design aids in SP-16 only provide 12 charts each for rectangular and circular column sections, with d'/D ratios in intervals of 0.05. However, in practice d'/D varies from 0.035 to 0.25. The project will prepare 57 charts each for the column sections, with d'/D ratios in intervals of 0.01, to minimize approximation errors. This will result in preparing a total of 2394 interaction curves covering different grades of steel and p/fck ratios, to aid in more accurate column design and analysis.
This document provides information about a steel structures design course. It includes the course objectives to expose students to steel design concepts and skills. It also outlines the typical stages of an engineering project including planning, design, construction, and operation/maintenance. Additionally, it defines common loads considered in steel design like dead loads, live loads, and wind loads. Finally, it describes common steel sections, grades of steel, and types of steel bolts used in construction.
This document contains lecture notes on mechanics of solids and structures from the University of Manchester. It covers topics related to centroids, moments of area, beams, and bending theory. Specifically, it provides definitions and examples of centroids, first and second moments of area, and introduces beam supports and equilibrium, beam shear forces and bending moments, and bending theory. The contact information for the lecturer, Dr. D.A. Bond, is also provided at the top.
This document discusses the need for raft foundations. Raft foundations are recommended when:
1) Building loads are heavy or soil capacity is low, so individual footings would cover too much area.
2) Soil contains weak lenses or cavities, making differential settlement hard to predict.
3) Structures are sensitive to differential settlement.
4) Structures like silos naturally suit raft foundations.
5) Floating foundations are needed over very weak soil.
6) Buildings require basements or underground pits.
7) Individual footings would experience large bending stresses.
Raft foundations increase capacity, decrease settlement, and equalize differential settlement compared to individual footings. However,
If both the ends of a beam are supported by end supports then the beam is known as Simply Supported Beam. One end of the beam is supported by roller support and the other end is supported by a hinged or pinned support. Copy the link given below and paste it in new browser window to get more information on Simply Supported Beam Examples:- http://www.transtutors.com/homework-help/mechanical-engineering/bending-moment-and-shear-force/simply-supported-beam-examples.aspx
Seismic design and construction of retaining wallAhmedEwis13
This document discusses seismic design considerations for retaining walls. It describes the common types of retaining walls, including gravity, cantilever, reinforced soil, and anchored bulkhead walls. Static lateral earth pressures are calculated using Rankine and Coulomb theories, with the Mononobe-Okabe method extending Coulomb theory to account for seismic inertial forces. Dynamic response of retaining walls is complex, with wall movement, pressures, and permanent displacements dependent on the response of the wall, backfill soil, and foundation soil to ground shaking.
Presentation1 integrity problems of concrete piles-emergencySuper Arc Consultant
This document discusses integrity problems that can occur in concrete piles. It begins by outlining common defective construction practices for bored piles, such as boring problems, improper drilling procedures, inadequate base cleaning, improper reinforcement cage fabrication, and poor concreting techniques. The document then discusses how pile testing can be used to identify anomalies, flaws, and defects in piles. It provides examples of anomalies that are not flaws, anomalies that are flaws, flaws that are not defects, and anomalies that are defects. The goal of pile testing is to evaluate pile integrity and ensure piles are constructed properly.
The document provides an overview of structural systems and principles. It discusses the early shelters people used, the history of structural engineering from ancient structures like pyramids to modern advances. Key concepts covered include load paths, types of loads (static, dynamic), supports, materials used in construction, and the structural design process. The role of structural engineering is to safely resist all loads on a structure through appropriate analysis and design.
The document provides details on the design of a reinforced concrete column footing to support a column load of 1100kN from a 400mm square column. It describes the design process which includes determining the footing size, calculating bending moment, reinforcement requirements, checking shear capacity and development length. The design example shows a 3.5m x 3.5m square footing with 12mm diameter bars at 100mm c/c is adequate to support the given load based on the specified material properties and design codes. Reinforcement and footing details are also provided.
Contours show lines connecting points of equal elevation on a map, with the lines usually shown at intervals of 5 or 10 meters. They are created by joining points of the same height on a map. Contours allow important information to be gathered like finding level land for construction or agriculture, or designing infrastructure like pipelines that require following the terrain.
3414 code of practice for joints in buildingssatejkeche
This standard provides guidance on designing and installing joints in masonry and concrete buildings. It defines various types of joints like expansion joints, construction joints, contraction joints, sliding joints, joint fillers, and waterbars. The standard outlines important considerations for joint design like evaluating dimensional changes due to temperature variations and moisture movement. Joints need to accommodate expansion and contraction of building materials to prevent cracking. The standard aims to minimize cracking by avoiding over-restraining materials' movement.
Anchorage and lap splicing Detailing of slabs, columns, beams, footingskarthickcivic
This document discusses Eurocode 2 and provides details on anchorage and lap splicing of reinforcement in slabs, columns, beams and footings according to Eurocode 2. It covers general provisions for anchorage length, including tables of minimum anchorage lengths for different bar diameters. It also discusses lap splicing requirements, including tables of minimum lap splice lengths. The document is intended to provide guidance on reinforcement detailing according to Eurocode 2.
This document discusses fundamentals of flexural bond including:
1. Bond strength and development length requirements for tension reinforcement according to the ACI code.
2. Simplified equations and factors that influence development length calculations.
3. Anchorage requirements including standard dimensions for bar hooks, development lengths for hooked bars, and transverse reinforcement requirements.
4. Additional topics on anchorage of web reinforcement, development bars in compression, bundled bars, bar cutoffs in beams, and bar splices. Diagrams and examples are provided to illustrate key concepts.
Structural engineering involves relating physical forces to structural elements that resist them. Analysis determines forces in each element of a defined structure, while design configures elements to resist known forces. The process iterates between analysis and design until complete. Structures resist vertical and horizontal loads, and include large items like bridges as well as everyday items. Structural design requires data on the structure type, site conditions like soil properties, and loading conditions from dead and live loads, wind, and earthquakes as defined by codes. Design methods are selected based on local practices.
This document discusses shear force and bending moment diagrams. It explains the concepts of shear force and bending moment and how to draw shear force and bending moment diagrams for beams subjected to different types of loading. The document is intended as a guide for students to understand shear force and bending moment diagrams.
This document discusses using quality assurance tests to identify defects in large diameter bored piles for two construction projects. For the first project, pile load tests, integrity tests, and coring identified necking, bulging, and a weak pile toe, likely due to a "soft toe" condition. The pile capacities were reduced and additional piles were added. For the second project, integrity and load tests found impedance reductions and doubtful pile integrity below certain depths. Load capacities were de-rated based on the test results. The conclusion emphasizes the importance of a comprehensive quality assurance program to ensure foundation safety and performance.
This document summarizes different types of piles used in construction foundations including friction piles, end bearing piles, sheet piles, load piles, and more. It describes how piles can be made of timber, steel, concrete, or composites. The document also outlines various pile driving methods such as drop hammers, single/double acting steam hammers, diesel hammers, vibratory drivers, and safety procedures for pile driving operations.
This document provides design aids for reinforced concrete structures based on Indian Standard IS: 456-1978 Code of Practice for Plain and Reinforced Concrete.
The design aids cover material strength and stress-strain relationships, flexural members, compression members, shear and torsion, development length and anchorage, working stress design, deflection calculation, and general tables. Charts and tables are provided for preliminary and final design of beams, slabs, and columns. Assumptions made in developing the design aids are explained. An example illustrates the use of the design aids. Important points regarding the use and limitations of the charts and tables are noted.
The design aids were prepared based on examination of international handbooks and consultation with Indian
This document is the sixth edition of the National Structural Code of the Philippines (NSCP) Volume I, which provides requirements for designing buildings, towers, and other vertical structures. It was published in 2010 by the Association of Structural Engineers of the Philippines. The code contains chapters on minimum design loads, materials, and other topics to guide structural design in compliance with the latest standards. The foreword expresses pride in the publication and updates to the code to regulate structural design for safety.
This contains methods of exploration in rock. How the rock samplers are taken. Quality of rock samples and its reporting. Along with the laboratory tests conducting on these rock samples.
The document describes a student project that aims to prepare design aids in the form of interaction curves for column design. The design aids in SP-16 only provide 12 charts each for rectangular and circular column sections, with d'/D ratios in intervals of 0.05. However, in practice d'/D varies from 0.035 to 0.25. The project will prepare 57 charts each for the column sections, with d'/D ratios in intervals of 0.01, to minimize approximation errors. This will result in preparing a total of 2394 interaction curves covering different grades of steel and p/fck ratios, to aid in more accurate column design and analysis.
This document provides information about a steel structures design course. It includes the course objectives to expose students to steel design concepts and skills. It also outlines the typical stages of an engineering project including planning, design, construction, and operation/maintenance. Additionally, it defines common loads considered in steel design like dead loads, live loads, and wind loads. Finally, it describes common steel sections, grades of steel, and types of steel bolts used in construction.
This document contains lecture notes on mechanics of solids and structures from the University of Manchester. It covers topics related to centroids, moments of area, beams, and bending theory. Specifically, it provides definitions and examples of centroids, first and second moments of area, and introduces beam supports and equilibrium, beam shear forces and bending moments, and bending theory. The contact information for the lecturer, Dr. D.A. Bond, is also provided at the top.
This document discusses the need for raft foundations. Raft foundations are recommended when:
1) Building loads are heavy or soil capacity is low, so individual footings would cover too much area.
2) Soil contains weak lenses or cavities, making differential settlement hard to predict.
3) Structures are sensitive to differential settlement.
4) Structures like silos naturally suit raft foundations.
5) Floating foundations are needed over very weak soil.
6) Buildings require basements or underground pits.
7) Individual footings would experience large bending stresses.
Raft foundations increase capacity, decrease settlement, and equalize differential settlement compared to individual footings. However,
If both the ends of a beam are supported by end supports then the beam is known as Simply Supported Beam. One end of the beam is supported by roller support and the other end is supported by a hinged or pinned support. Copy the link given below and paste it in new browser window to get more information on Simply Supported Beam Examples:- http://www.transtutors.com/homework-help/mechanical-engineering/bending-moment-and-shear-force/simply-supported-beam-examples.aspx
Seismic design and construction of retaining wallAhmedEwis13
This document discusses seismic design considerations for retaining walls. It describes the common types of retaining walls, including gravity, cantilever, reinforced soil, and anchored bulkhead walls. Static lateral earth pressures are calculated using Rankine and Coulomb theories, with the Mononobe-Okabe method extending Coulomb theory to account for seismic inertial forces. Dynamic response of retaining walls is complex, with wall movement, pressures, and permanent displacements dependent on the response of the wall, backfill soil, and foundation soil to ground shaking.
Presentation1 integrity problems of concrete piles-emergencySuper Arc Consultant
This document discusses integrity problems that can occur in concrete piles. It begins by outlining common defective construction practices for bored piles, such as boring problems, improper drilling procedures, inadequate base cleaning, improper reinforcement cage fabrication, and poor concreting techniques. The document then discusses how pile testing can be used to identify anomalies, flaws, and defects in piles. It provides examples of anomalies that are not flaws, anomalies that are flaws, flaws that are not defects, and anomalies that are defects. The goal of pile testing is to evaluate pile integrity and ensure piles are constructed properly.
The document provides an overview of structural systems and principles. It discusses the early shelters people used, the history of structural engineering from ancient structures like pyramids to modern advances. Key concepts covered include load paths, types of loads (static, dynamic), supports, materials used in construction, and the structural design process. The role of structural engineering is to safely resist all loads on a structure through appropriate analysis and design.
The document provides details on the design of a reinforced concrete column footing to support a column load of 1100kN from a 400mm square column. It describes the design process which includes determining the footing size, calculating bending moment, reinforcement requirements, checking shear capacity and development length. The design example shows a 3.5m x 3.5m square footing with 12mm diameter bars at 100mm c/c is adequate to support the given load based on the specified material properties and design codes. Reinforcement and footing details are also provided.
Contours show lines connecting points of equal elevation on a map, with the lines usually shown at intervals of 5 or 10 meters. They are created by joining points of the same height on a map. Contours allow important information to be gathered like finding level land for construction or agriculture, or designing infrastructure like pipelines that require following the terrain.
3414 code of practice for joints in buildingssatejkeche
This standard provides guidance on designing and installing joints in masonry and concrete buildings. It defines various types of joints like expansion joints, construction joints, contraction joints, sliding joints, joint fillers, and waterbars. The standard outlines important considerations for joint design like evaluating dimensional changes due to temperature variations and moisture movement. Joints need to accommodate expansion and contraction of building materials to prevent cracking. The standard aims to minimize cracking by avoiding over-restraining materials' movement.
Anchorage and lap splicing Detailing of slabs, columns, beams, footingskarthickcivic
This document discusses Eurocode 2 and provides details on anchorage and lap splicing of reinforcement in slabs, columns, beams and footings according to Eurocode 2. It covers general provisions for anchorage length, including tables of minimum anchorage lengths for different bar diameters. It also discusses lap splicing requirements, including tables of minimum lap splice lengths. The document is intended to provide guidance on reinforcement detailing according to Eurocode 2.
This document discusses fundamentals of flexural bond including:
1. Bond strength and development length requirements for tension reinforcement according to the ACI code.
2. Simplified equations and factors that influence development length calculations.
3. Anchorage requirements including standard dimensions for bar hooks, development lengths for hooked bars, and transverse reinforcement requirements.
4. Additional topics on anchorage of web reinforcement, development bars in compression, bundled bars, bar cutoffs in beams, and bar splices. Diagrams and examples are provided to illustrate key concepts.
Sp 34-1987 handbook on reinforcement and detailingjemmabarsby
This document is a handbook on reinforcement and detailing published by the Bureau of Indian Standards. It provides information on different types of steel used for reinforcement in concrete, including mild steel, medium tensile steel, high strength deformed steel bars, and hard-drawn steel wire fabric. It specifies the requirements for each type of steel in terms of chemical composition, mechanical properties, dimensions and tolerances. The handbook also covers detailing functions, structural drawings, general detailing requirements, bar bending schedules, and detailing of different structural elements like foundations, columns, beams etc.
Bar Bending Schedule (BBS) is a chart which gives a clear picture of bar length, diameter of bar ,bar mark ,location of bar.
It allow workers to place steel properly.
The superstructure of a building consists of elements above the foundation like beams, columns, lintels, roofing and flooring. Beams are horizontal members that carry loads and transfer them to columns or walls. Reinforced concrete beams are designed to resist both bending moments and shear forces from loads. There are different types of beams like simply supported, fixed, cantilever, continuous and overhanging beams which are designed based on how they are supported. Columns are vertical load bearing members that transfer loads from beams and slabs to the foundation. Common column types include long, short and intermediate columns. Lintels are short horizontal members that span small openings like doors and windows and transfer loads to masonry, steel or reinforced concrete
The document discusses proper detailing of reinforced concrete structures, which is essential for safety and structural performance. It provides guidelines and examples of good and bad detailing practices for common reinforced concrete elements like slabs, beams, columns, and foundations. Proper detailing is important to avoid construction errors and ensure the structural design works as intended under gravity and seismic loads.
Deduction of opening , Number of bars and Bar Bending SchedulingYash Patel
This document provides information about the quantities required for reinforced concrete beam. It includes:
(a) The reinforced concrete quantity is 1.14 cubic meters and formwork quantity is 10 square meters.
(b) The total weight of steel is calculated as 158.68 kilograms which includes straight bars, bent up bars, anchor bars and stirrups.
(c) A bar bending schedule is prepared listing the bar details like diameter, shape, length, number, total length and weight.
(d) The percentage of steel with respect to concrete is calculated as 12.08%
In 3 sentences, this summary covers the key aspects of the document which are the quantities of concrete and
This document provides standards of practice for architects/engineers and reinforcing steel detailers in detailing reinforced concrete structures. It defines the responsibilities of both parties in developing structural drawings and placing drawings. The document is divided into three parts: Part A addresses the responsibilities of the architect/engineer in providing structural drawings; Part B covers the responsibilities of detailers in developing placing drawings based on the structural drawings; and Part C contains reference tables and figures. The goal is to establish clear responsibilities for each party and ensure complex modern designs can be accurately detailed and constructed.
This document provides details about reinforcing concrete columns and footings. It discusses that columns are vertical members that support loads and transmit them downward. Reinforcement is added to reduce column size and resist compression and bending forces. The main reinforcement runs longitudinally and is arranged in square, rectangular, or circular patterns. Minimum and maximum longitudinal steel requirements are specified. Transverse reinforcement is also included to help position longitudinal bars and confine the concrete.
This document provides details on the design of a continuous one-way reinforced concrete slab. It includes minimum thickness requirements, equations for calculating moments and shear, maximum reinforcement ratios, and minimum reinforcement ratios. An example is then provided to demonstrate the design process. The slab is designed to have a thickness of 6 inches with 0.39 in2/ft of tension reinforcement in the negative moment region and 0.33 in2/ft in the positive moment region.
The document summarizes the design of beam-and-slab systems. It describes how the one-way slab is designed as a continuous slab spanning the beam supports using moment distribution methods or a simplified coefficient method. Interior beams are designed as T-beams and edge beams as L-beams, which provide greater flexural strength than conventional beams. The beam and slab must be securely connected to transfer shear forces between them. The slab is reinforced as a one-way system and the beams are designed as simply supported beams spanning their supports.
This presentation summarizes the key aspects of one-way slab design. It defines one-way slabs as having an aspect ratio of 2:1 or greater, with bending primarily along the long axis. The presentation discusses the types of one-way slabs including solid, hollow, and ribbed. It also outlines the design considerations for one-way slabs according to the ACI code, including minimum thickness, reinforcement ratios, and bar spacing. An example problem demonstrates how to design a one-way slab for a given set of loading and dimensional conditions.
Simplified design of reinforced concrete buildings Sarmed Shukur
This document provides an overview of a publication titled "Simplified Design of Reinforced Concrete Buildings" which outlines simplified design methods for reinforced concrete structures. The publication aims to reduce design time by providing timesaving procedures and aids for experienced designers. It focuses on conventional reinforced concrete buildings between 3-5 stories tall with typical framing systems. The document discusses loading calculations, frame analysis techniques using coefficients or analytical methods, and preliminary sizing of structural elements like floors, columns, shear walls and footings.
This document provides the full text of the Indian Standard IS 456:2000 Code of Practice for Plain and Reinforced Concrete. Some key details include:
- It establishes standards and guidelines for the design, materials, workmanship, construction, and testing of plain and reinforced concrete structures.
- Major revisions from previous versions include expanded guidance on durability requirements, modified acceptance criteria for concrete, and the inclusion of higher strength concrete grades.
- It contains sections on materials, design considerations, structural design principles, and testing/inspection. The limit state and working stress methods for structural design are both included.
This paper identifies genes required for accurate chromosome segregation through systematic yeast screens. The researchers performed genome-wide synthetic lethal and synthetic dosage lethal screens using kinetochore mutants as starting points. They identified 211 nonessential gene deletions that were unable to tolerate defects in kinetochore function. A secondary screen then assessed defects in chromosome segregation. Genes identified were enriched for those with known roles in chromosome segregation. They also uncovered genes with diverse functions, like RCS1, which encodes an iron transcription factor. RCS1 was identified in all three screens and was confirmed to play a role in chromosome stability. The screens revealed genes important for chromosome maintenance that may not have been found through other approaches.
Development Length In Recycled Steel Bar ReinforcementCSCJournals
Reinforcing concrete with steel introduces a component of ductility that is impossible to attain in concrete alone due to its inherently fragile nature. This presupposes that there is such bonding between the two materials that at the moment of failure of concrete, steel holds onto the concrete and simultaneously yields to facilitate an overall ductile deformation. The tendency for steel bars to possess excessive strength makes it impossible for timely permanent deformation to occur, leading to failure in concrete long before the steel reinforcement yields. Steel bars normally have a yield stress range around which the concrete-steel composite is designed. Due to the unpredictable nature of recycled steel composition however, the resulting steel bar strength values are hard to guarantee even in the same production batch. In this paper, the tendency for steel bars to have higher than predicted yield stress levels is studied using a statistical-probabilistic approach. The batch of 72 recycled steel bars subjected to monotonic loading to failure and spark spectroscopy in this study shows a normal distribution of steel yield stresses. The cumulative distribution function P(X ≥ χ) was subsequently evaluated for 550Mpa. Over 20% of the samples were found to be above the 550Mpa design value and therefore the development length, which is directly proportional to the steel bar yield ends up with the same probability stretch. Direct proportionality between the growing yield values and the boron content has also been graphically demonstrated.
This document provides a bar bending schedule summary for a bridge project in Thailand. It includes details of reinforcement bars needed for the Deck D2 section, including bar marks, quantities in pieces and meters, and total weights in tons for different bar sizes and bend configurations (e.g. one bend side, two bend side, three bend above). The total bar mark count is 79, total bar quantity is 2,278 pieces, and total linear length is 11,741 meters.
This document discusses the key materials used in reinforced concrete, including cement made from limestone, clay, and shale and fused in a kiln with gypsum added. Concrete consists of cement, coarse and fine aggregates like stone chips and sand, and water, with admixtures sometimes added to improve properties. Reinforcement is also discussed, including reinforcing bars and prestressing steel that bond strongly to the concrete.
This document provides an overview of earthquake safety for educational buildings in Nepal. It discusses the seismicity of Nepal and failure mechanisms of buildings during earthquakes. Guidelines are provided on site selection, building forms, materials, and construction quality to improve earthquake resistance. Techniques for assessing safety of masonry buildings and retrofitting existing buildings are also described. The document aims to help designers and builders construct new earthquake-resistant educational facilities and strengthen existing vulnerable buildings.
This document provides information on the design of reinforced concrete beams, including:
1. It outlines the three basic design stages: preliminary analysis and sizing, detailed analysis of reinforcement, and serviceability calculations.
2. It describes how to calculate the lever arm, depth of the neutral axis, and required area of tension and compression reinforcement for singly and doubly reinforced beams.
3. It discusses considerations for preliminary sizing of beams, including required cover, breadth, effective depth, shear stress limits, and span-depth ratios. Trial calculations are suggested to determine suitable beam dimensions.
This document discusses the limit state method for designing reinforced concrete beams. It describes key concepts like limit states, stress-strain curves for concrete and steel, and the parameters used to calculate the depth of the neutral axis and moment of resistance. There are three main types of reinforced concrete beams discussed: singly reinforced, doubly reinforced, and singly or doubly reinforced flanged beams. The document focuses on the design and analysis of singly reinforced beams, providing examples of determining the moment of resistance of a given cross-section, as well as designing a beam to resist a specific bending moment.
The document discusses different methods of concrete design including working stress method, limit state method, ultimate load method, and probabilistic method. It then focuses on explaining the limit state method. Key points include:
- The limit state method aims to achieve an acceptable probability that a structure will not reach an unsafe limit state during its lifetime.
- Structures must withstand all reliably expected loads over lifetime and satisfy serviceability requirements like deflection and cracking limits.
- Important limit states to consider in design are flexure, compression, shear, and torsion failure modes.
- Examples are given of analyzing and designing reinforced concrete beam sections using the limit state method. Design calculations for moment of resistance are shown.
This document provides instructional objectives and content on bond, anchorage, development length, and splicing of reinforcement. It discusses:
- The importance of bond between steel and concrete to allow them to act together without slip.
- Development length, which is the length required to develop full bond.
- Design bond stress, which is the average shear stress along the reinforcement.
- Values of design bond stress in tension and compression for plain and deformed bars.
- Equations to calculate the development length of a single bar or bundled bars.
- Requirements for checking development lengths of bars in tension.
1. Reinforced masonry working stress design of flexural members uses assumptions including plane sections remaining plane after bending and neglecting all masonry in tension.
2. The balanced condition occurs when the extreme fiber stress in the masonry equals the allowable compressive stress and the tensile stress in reinforcement equals the allowable tensile stress.
3. Shear design of reinforced masonry considers mechanisms such as dowel action and the ability of shear reinforcement to restrict crack growth and resist tensile stresses. Allowable shear stresses depend on the presence of shear reinforcement.
This document summarizes key concepts in rigid pavement design as outlined by Westergaard. It describes:
1) Westergaard's definition of modulus of subgrade reaction and radius of relative stiffness, which characterize the interaction between the rigid pavement slab and underlying soil.
2) Westergaard's stress equations which calculate critical stresses at interior, edge, and corner regions due to wheel loads and temperature variations.
3) Considerations for joint design including expansion joints, contraction joints, dowel bars, and tie bars to allow for movement while transferring loads between panels.
Reinforced concrete slabs are used in floors, roofs, and walls. They can span in one or two directions and be supported by beams, walls, or columns. This document discusses the design of reinforced concrete slabs, including types of slabs, load analysis, shear design, reinforcement details, and provides examples of designing solid slabs spanning in one direction. The goal is to teach students to properly design and analyze reinforced concrete slabs according to code.
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.
The document discusses different methods of designing concrete structures, focusing on the limit state method. It describes the limit state method's goal of achieving an acceptable probability that a structure will not become unsuitable for its intended use during its lifetime. The document then discusses stress-strain curves for concrete and steel. It covers stress block parameters and equations for calculating the depth of the neutral axis and moment of resistance for singly reinforced concrete beams. The document concludes by providing examples of analyzing an existing beam section and designing a new beam section.
This document provides instructions and questions for a structural design exam. It consists of 4 questions. Students must answer question 1 and any other two questions. Question 1 involves calculating bending moments, designing reinforcement, and determining shear capacity for concrete beams. Question 2 involves checking the adequacy of steel sections and designing a bolt connection. Question 3 uses force methods to determine reactions and draws shear and bending moment diagrams. Question 4 analyzes a frame under vertical and lateral loads to determine reactions and internal forces at specific points. The document also includes relevant design formulas and appendices on load combinations, bending moment coefficients, and steel design strengths.
This document discusses the design of drillstrings and bottom hole assemblies (BHAs). It covers the components of drillstrings including drill pipe, drill collars, heavy weight drill pipe, and stabilizers. It also discusses BHA configurations and the purpose and components of BHAs. The document provides information on selecting drill collars and drill pipe grades. It covers criteria for drillstring design including collapse pressure, tension loading, and dogleg severity analysis.
Predictive model of moment of resistance for rectangular reinforced concrete ...Alexander Decker
This document presents a predictive model for calculating the moment of resistance (MR) for rectangular reinforced concrete sections. The model is developed based on stress-strain analysis of a singly reinforced concrete beam. The governing equation relates MR to the concrete compressive strength (fcu), breadth (b), and effective depth (d). Simulation results show that MR increases with larger b and d values. MR also increases at a higher rate with greater d due to its quadratic relationship in the equation, whereas the increase is linear with b. The model allows accurate selection of section dimensions for structural design based on required resistance.
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.
Unit 5 Approximate method of analysis (1).pdfSathyaPrabha20
The document discusses approximate analysis methods for structural analysis. It introduces the substitute frame method where a multi-storey frame is simplified to study internal forces in individual members. Portal and cantilever methods are described to analyze frames under lateral loads. The objectives are to understand approximate methods and compute internal forces using substitute frame, portal and cantilever techniques. Key steps involve selecting a substitute frame, determining loads, calculating distribution factors, and analyzing to obtain shear and moment diagrams.
Abstract (Dutch)
Samengestelde betonnen liggers vervaardigd van prefab voorgespannen- en/of gewapende elementen zijn zeer populair in de huidige praktijk van de civiele techniek. Twee betonnen, samengestelde delen van de ligger worden gestort op verschillende tijdstippen. Verschillende elasticiteitsmoduli, opeenvolgende belastingaanbrenging, en verschillend krimp en kruip veroorzaken een herverdeling van de normaalspanning en ongelijke rekken en spanningen in twee aansluitende vezels in het aansluitvlak.
Dit seminar richt zich op de berekening volgens de EN 1992-1-1 en EN 1992-2. De aannames met betrekking tot de berekening en de controle van de gewapende en/of voorgespannen samengestelde liggers en doorsnedes zal worden toegelicht.
Ook wordt er ingegaan op:
• De spanning/rek respons van de doorsnede belast door normaalkracht en buigende momenten,
• De principes van het gebruik van de “initiële toestand” in berekeningen van de uiterste grenstoestand en de bruikbaarheidsgrenstoestand,
• De controle van dwarskracht en wringing,
• De interactie tussen alle snedekrachten,
• De principes van de controles van de spanningbeperking,
• De achtergrond van de scheurwijdtecontrole
Speciale aandacht zal er worden gegeven aan de berekening van de schuifspanning in het aansluitvlak, en de beschouwing van de invloed van de verschillende leeftijd van de betonnen delen met betrekking tot de schuifspanningen. Een alternatieve berekeningsmethode ten opzichte van de Eurocode 2 zal worden voorgesteld en worden getest.
De praktische voorbeelden volgens de Eurocode 2 zullen worden uitgevoerd met behulp van de IDEA StatiCa software.
The document discusses crack width calculations and limits for reinforced concrete structures according to BS5400-4. It provides equations to calculate the crack width based on factors like steel and concrete properties, bar location and diameter, moment, and concrete cover thickness. The calculated crack width should not exceed limits in the standard which depend on the structure's exposure environment, with more severe environments requiring narrower crack widths.
This document discusses the design of drillstrings and bottom hole assemblies (BHAs). It covers the components of drillstrings including drill pipe, drill collars, heavy weight drill pipe, stabilizers, and directional control equipment. It provides information on drill pipe and tool joint selection, as well as how to calculate the approximate weight of drill pipe and tool joint assemblies. The document also discusses bottom hole assembly design considerations such as configuration types, bending strength ratios, and stiffness ratios. Additional topics covered include drill collar selection, drillstring design criteria such as collapse, tension, and dogleg severity analysis.
This document discusses casing design considerations and methodology. It covers key factors that influence casing design like loading conditions, formation strength, and costs. It also describes the graphical method for casing design which involves plotting burst, collapse, and tensile loads on a pressure-depth graph and selecting appropriate casing grades that exceed these loads. Safety factors are also discussed. The document provides detailed steps for constructing the graphical design including calculating burst, collapse, and tensile lines and selecting suitable casing grades based on the intersections.
The document discusses casing design considerations. It begins by outlining the general criteria considered in casing design, including loading conditions, formation strength, availability/cost of casing strings, and expected deterioration over time. It then describes how casing is designed to withstand burst, collapse, tension, and biaxial stresses using safety factors. Graphical and mathematical methods are presented for designing casing strings to meet differential pressure requirements at varying depths. Considerations like centralizer spacing and stretch are also covered. The document provides a detailed overview of the factors and calculations involved in optimizing casing design.
Similar to Development Length Hook Splice Of Reinforcements (20)
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CHAPTER
DEVELOPMENT LENGTH,
23 HOOK
REINFORCEMENTS
& SPLICE OF
23.1 INTRODUCTION
The failure of the reinforced concrete structure commonly caused by incorrect reinforcements detail.
Reinforcement detail includes the development length, hook (anchorage) and splice between
reinforcements.
The strength of reinforcing bar is based on the bond strength between steel reinforcement and
concrete material. Due to external load the bond stress between steel reinforcement and concrete can
be exceeded and cause crushing and splitting of the surrounding concrete.
The followings are the major factors of the bond strength, as follows :
Adhesion between concrete and steel reinforcement.
Gripping effect from drying shrinkage of the surrounding concrete.
Shear interlock of bar deformation and surrounding concrete.
Concrete quality.
Diameter of the steel reinforcement.
This chapter describes the analysis of development length, standard hook, development of flexural
reinforcement, bar cut off and splice of reinforcements.
23.2 DEVELOPMENT OF BOND STRESS
23.2.1 GENERAL
Bond stress is the primary result of the shear interlock between the steel reinforcement and
surrounding concrete. Bond stress can be defined as local shearing stress per unit area of the bar
surface. Three types of test can be used to determine the bond quality which is pull-out test,
embedded rod test and beam test.
23.2.2 PULL OUT BOND
The pull out bond is determined based on the pull out force applied to the embedded steel
reinforcement with prescribed embedded length.
The pull out bond strength can be calculated based on the average bond stress μ, as follows :
Tnb = μ(πdb )ld [23.1]
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where :
Tnb = bond strength of embedded reinforcement
μ = average bond stress per unit area of bar surface
db = diameter of reinforcement
ld = embedded length (development length)
The tensile force at the bar cross section is :
1 2
T= πdb fs [23.2]
4
where :
T = tensile force at bar cross section
db = diameter of reinforcement
fs = stress of bar
The two variables above must be in static horizontal equilibrium, as follows :
μ(πdb )ld =
1 2
πdb fs [23.3]
4
So the development length is derived as :
db fs
ld = [23.4]
4μ
23.3 DEVELOPMENT LENGTH
23.3.1 GENERAL
Development length is defined as minimum length of bar in which the bar stress can increase
from zero to the yield strength. If the distance is less than the development length the bar will pull
out the concrete. The development length is a function of yield stress, bar diameter and average
bond stress at surrounding concrete.
23.3.2 BASIC DEVELOPMENT LENGTH
ACI code uses the concept of development length rather than average bond stress. The average bond
stress is determined based on the test result and function of the concrete compressive strength.
Empirically the average bond stress is calculated, as follows :
9.5 f 'c lb
μ= ≤ 800 [23.5]
db in2
where :
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μ = average bond stress per unit area of bar surface
f’c = concrete compressive strength
db = diameter of reinforcement
or can be simply written as :
μ = k f 'c [23.6]
Rewritten the above condition we can obtain the basic development length, as follows :
μ(πdb )ld = A b fy
k f 'c (πdb )ld = A b fy
[23.7]
⎛ A b fy ⎞
ldb = k1⎜ ⎟
⎜ f' ⎟
⎝ c ⎠
23.3.3 DEVELOPMENT LENGTH OF TENSION BAR
A. Original Development Length
The basic development length of tension bar is :
TABLE 23.1 DEVELOPMENT LENGTH OF TENSION BAR
SI psi
ld 15fy αβγλ ld 3fy αβγλ
= =
db ⎛ c + K tr ⎞ db ⎛ c + K tr ⎞
16 f 'c ⎜
⎜ d
⎟
⎟ 40 f 'c ⎜
⎜ d
⎟
⎟
⎝ b ⎠ ⎝ b ⎠
⎛ c + K tr ⎞
≤ 1.5⎜
⎜ d
⎟ ≤ 2. 5
⎟
⎝ b ⎠
The transverse reinforcement index is defined as :
TABLE 23.2 KTR
SI psi
A tr fyt A tr fyt
K tr = K tr =
260sn 1500sn
where :
Ktr = transverse reinforcement index
Atr = area of transverse reinforcement through the
longitudinal bar being developed
fyt = yield strength of transverse reinforcement
Ktr can be used conservatively = 0.
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B. α, β, γ, λ & c Factor
The α factor is bar location factor determined, as follows :
TABLE 23.3 BAR LOCATION FACTOR α
LOCATION α
Horizontal reinforcement placed more than 12” (300 mm) fresh concrete 1.3
Other Reinforcement 1.0
The β factor is coating factor determined, as follows :
TABLE 23.4 COATING FACTOR β
COATING β
Epoxy coated bar with cover less than 3db / clear spacing less than 6db 1.5
All epoxy coated bar 1.2
Uncoated reinforcement 1.0
The product of αβ must not exceed 1.7.
The γ factor is bar size factor determined, as follows :
TABLE 23.5 BAR SIZE FACTOR γ
BAR SIZE γ
< 20 mm 0.8
> 25 mm 1.0
The c factor is spacing / cover dimension factor determined as the smaller of :
Distance from center of bar to the nearest concrete surface.
0.5 of center to center spacing of the bar being developed.
C. Simplified Development Length
For the design purpose the simplified development length formula is often used, as follows :
TABLE 23.6 SIMPLIFIED DEVELOPMENT LENGTH OF TENSION BAR – PSI UNIT
≤ NO. 6
CASE > NO. 7
(DEFORMED BAR)
Clear spacing of developed bar
> db, stirrup not less than the
ld fy αβλ ld fy αβλ
code minimum requirement = =
db 25 f 'c db 20 f 'c
Clear spacing of developed bar
> 2db, clear cover > db
ld 3fy αβλ ld 3fy αβλ
Other = =
db 50 f 'c db 40 f 'c
The development length ld must be greater than 12 inch.
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TABLE 23.7 SIMPLIFIED DEVELOPMENT LENGTH OF TENSION BAR – SI UNIT
≤ NO. 6
CASE > NO. 7
(DEFORMED BAR)
Clear spacing of developed bar
> db, stirrup not less than the
ld 12fy αβλ ld 12fy αβλ
code minimum requirement = =
db 25 f 'c db 20 f 'c
Clear spacing of developed bar
> 2db, clear cover > db
ld 18 fy αβλ ld 18 fy αβλ
Other = =
db 25 f 'c db 20 f 'c
The development length ld must be greater than 300 mm.
23.3.4 DEVELOPMENT LENGTH OF COMPRESSION BAR
The development length for compression bar is shorter than in the tension bar, because there is no
concrete cracking occurs.
The development length of compression bar is :
TABLE 23.8 DEVELOPMENT LENGTH OF COMPRESSION BAR
psi SI
0.02fy db fy db
ld = ≥ 0.0003 fy db ld = ≥ 0.044 fy db
f 'c 4 f 'c
The development length of compression bar ld must be greater than 8 inch / 200 mm.
23.3.5 DEVELOPMENT LENGTH OF BUNDLED BAR
The development length of bundled bar either in tension or compression is greater than development
length of single bar, because the bundled bar reduce the surface area surrounding concrete.
TABLE 23.9 DEVELOPMENT LENGTH OF BUNDLED BAR
3 BUNDLED 4 BUNDLED
1.2ld 1.33ld
ld is calculated based on the equivalent single bar area having the same area of bundled bar.
23.3.6 DEVELOPMENT LENGTH OF WELDED WIRE FABRIC
The development length of plain welded wire fabric in tension is :
⎛ A w fy λ ⎞
ld = 0.27⎜ ⎟
⎜ s f' ⎟ [23.8]
⎝ w c ⎠
where :
Aw = cross section area of wire
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sw = spacing of wire
fy = yield strength of wire (psi)
f’c = concrete compressive strength (psi)
The development length must be greater than 6 inch or (sw + 2 inch).
23.3.7 DEVELOPMENT LENGTH OF WEB REINFORCEMENT
The following figure shows the development length of double U stirrup, as follows :
FIGURE 23.1 DOUBLE U STIRRUP
If the development length above can not fit the depth of the member, the development length
can be extended to full depth of member.
23.4 STANDARD HOOK
23.4.1 GENERAL
When the insufficient length can not be provided to develop a bar then the bar needed to be
anchorage. Two type of standard hooks can be used which is 90o hook and 180o hook.
23.4.2 EMBEDMENT LENGTH OF HOOK
The hook development length is obtained from the basic development length for standard hook lhb
multiplied with factor.
The basic development length for standard hook is :
TABLE 23.10 BASIC DEVELOPMENT LENGTH OF STANDARD HOOK
psi SI
1200 db 100db
lhb = lhb =
f 'c f 'c
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The hook development length then calculated as follows :
ldh = λlhb [23.9]
where :
ldh = hook development length
λ = multiplier factor
lhb = basic development length of standard hook
The following is the multiplier factor λ, as follows :
TABLE 23.11 MULTIPLIER FACTOR OF HOOK DEVELOPMENT LENGTH
CONDITION λ
fy
λ=
400
fy different from 400 MPa / 60000 psi
fy
λ=
60000
o
For 90 hook cover not less than 2”
λ = 0 .7
No. 11 bar and smaller cover not less than 2.5”
No. 11 bar and smaller stirrup spacing less than 3d
b
λ = 0 .8
Light weight concrete λ = 1 .3
Epoxy coating λ = 1 .2
23.4.3 90O HOOK AND 180O HOOK
The figure below is the standard hook for 90o hook and 180o hook.
FIGURE 23.2 STANDARD HOOK
The diameter of the bend of hook is :
TABLE 23.12 BEND DIAMETER OF HOOK
NO. 3 – 8 NO. 9, 10, 11 NO. 14 & 18
D = 6db D = 8db D = 10db
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The figure below is the hook for No. 3 bar stirrup.
FIGURE 23.3 HOOK FOR STIRRUP NO. 3
The diameter of the bend of stirrup is :
TABLE 23.13 BEND DIAMETER OF STIRRUP
NO. 3 – 5 NO. 6 – 8
D = 4db D = 6db
23.5 DEVELOPMENT OF FLEXURAL REINFORCEMENT & CUT OFF POINT
23.5.1 GENERAL
Flexural reinforcement has different treatment of development length. The flexural reinforcement in one
span may designed due to different value of bending moment so the reinforcement is different.
We have to determine the location where the bar can be cut and the development length from the point
of maximum moment.
23.5.2 DEVELOPMENT LENGTH OF FLEXURAL REINFORCEMENT
A. General
The flexural reinforcements are designed using the maximum bending moment value such as at
mid span (positive moment) and at support (negative moment). To ensure the full development the
flexural reinforcement must be extended at least development length ld from the point of maximum
bending moment.
B. Rules of Positive Moment Reinforcement
The followings are the rules of the development length of flexural reinforcement for positive moment, as
follows :
The reinforcement must be extended at least development length ld from the point of
maximum bending moment.
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In simple beam structure, at least 1/3 of positive moment reinforcement must be extended at
least 6 inch into support without bending.
In continuous beam, at least ¼ of positive moment reinforcement must be extended at least
6 inch into support without bending.
Interior continuous beam without closed stirrup, at least ¼ of positive moment
reinforcement shall be spliced with spliced class A.
C. Rules of Negative Moment Reinforcement
The followings are the rules of the development length of flexural reinforcement for negative moment,
as follows :
The reinforcement must be extended at least development length ld from the point of
maximum bending moment.
Negative moment reinforcement must be anchored to the supporting column or member.
At least 1/3 of total reinforcement for negative moment must be extended beyond the
inflection point > d or 12 db or 1/16 of clear span the larger value is taken.
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23.5.3 BAR CUT OFF POINT
A. General
The critical location of the flexural reinforcement is where there is rapid drop in the bending moment
such as inflection point (zero moment). To ensure the full development length the flexural
reinforcement must be extended beyond the inflection point with a distance 12db or d which is
greater.
B. Rules for All Reinforcements
The followings are the rules of the bar cut off for all reinforcements, as follows :
Bars must be extended d or 12 db beyond the theoretical flexural cut off points except at
support / end of cantilever.
Bars must be extended ld from the theoretical flexural cut off point of adjacent bar.
23.5.4 SKETCH OF FLEXURAL DEVELOPMENT LENGTH
A. General
This section shows the flexural development sketch of positive moment reinforcement and negative
moment reinforcement based on the all rules at previous section.
B. Positive Moment Reinforcement
The figure below shows the flexural development length of positive moment reinforcement.
FIGURE 23.4 FLEXURAL DEVELOPMENT LENGTH – POSITIVE MOMENT REINFORCEMENT
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C. Negative Moment Reinforcement
The figure below shows the flexural development length of negative moment reinforcement.
FIGURE 23.5 FLEXURAL DEVELOPMENT LENGTH – NEGATIVE MOMENT REINFORCEMENT
23.6 SPLICE OF REINFORCEMENTS
23.6.1 GENERAL
The bars are produced in standard length so sometime it is needed to be spliced. The splice of the
reinforcement must ensure that it can develop yield stress along the splice length.
There are three types of splice, as follows :
Lap Splice, lapping of two bars with determined splice length (< bar No. 11).
Mechanical Connecting, splice of reinforcement using the connector / coupler.
Welding, splice by weld the two reinforcements (> bar No. 11).
23.6.2 LAP SPLICE OF TENSION BAR
There are two types of lap splice of tension bar according to ACI code, as follows :
Class A.
Class B.
The splice length of splice class A is :
ls = 1.0ld ≥ 12" [23.10]
where :
ls = splice length
ld = development length
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The splice length of splice class B is :
ls = 1.3ld ≥ 12" [23.11]
where :
ls = splice length
ld = development length
The following table shows the conditions of tension lap splice, as follows :
TABLE 23.14 TENSION LAP SPLICE
MAXIMUM % OF SPLICED BAR
As PROVIDED / As REQUIRED
50% 100%
≥2 Class A Class B
<2 Class A Class B
23.6.3 LAP SPLICE OF COMPRESSION BAR
The lap splice of compression bar is :
TABLE 23.15 COMPRESSION LAP SPLICE
fy psi SI
≤ 60000 psi / 400 MPa ls ≥ 0.0005 fy db ls ≥ 0.07 fy db
> 60000 psi / 400 MPa (
ls ≥ 0.0009fy − 24 db ) (
ls ≥ 0.13fy − 24 db )
23.7 DETAIL OF REINFORCEMENTS
23.7.1 GENERAL
The most important thing in the reinforced concrete structure is the reinforcement detail. After the
reinforced concrete member is analyzed and designed a structural engineer must make a
reinforcement detail, splice of reinforcement, bar bending schedule because the engineer is the
only person who knows the location of critical section of the member, these information then used by
the contractor when they build the structure.
23.7.2 SPACING LIMITS
A. General
For ensure the workability of the concrete the spacing of the reinforcement must be limited so the
spacing is not o small compared to the size of the coarse aggregate.
B. Minimum Spacing
Minimum clear spacing of between bars is :
db ≥ 1" [23.12]
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where :
db = diameter of bar
Minimum clear spacing of bar more than one layers is :
1" [23.13]
Minimum clear spacing of longitudinal reinforcement in compression member with tied and spiral
transverse reinforcement is :
(1 − 1.5)db ≥ 1"−1.5" [23.13]
where :
db = diameter of bar
C. Maximum Spacing
Maximum spacing between bars must not spaced greater than :
3hf ≤ 18" [23.14]
where :
hf = slab thickness
23.7.3 END SPAN OF CONTINUOUS BEAM
The figure below shows the typical detail of reinforcement for end span in continuous reinforced
concrete structure.
FIGURE 23.6 END SPAN OF CONTINUOUS BEAM
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23.7.4 INTERIOR SPAN OF CONTINUOUS BEAM
The figure below shows the typical detail of reinforcement for interior span in continuous reinforced
concrete structure.
FIGURE 23.7 INTERIOR SPAN OF CONTINUOUS BEAM
23.7.5 COLUMN
The figure below shows the typical detail of reinforcement for column.
FIGURE 23.8 COLUMN
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