This document provides guidance on designing reinforced concrete slab systems, including one-way and two-way slabs, using web-based software. It introduces common slab types, design methods, assumptions, and considerations. The document then gives step-by-step examples of designing a one-way continuous slab and a simply supported two-way slab. It demonstrates the software's input/output interface by guiding the user through the full design process for each example slab. The guidance concludes by listing additional slab design examples available on the web-based software.
- The document describes the design and detailing of flat slabs, which are concrete slabs supported directly by columns without beams.
- Key aspects covered include dimensional considerations, analysis methods, design for bending moments including division of panels and limiting negative moments, shear design and punching shear, deflection and crack control, and design procedures.
- An example problem is provided to illustrate the full design process for an internal panel with drops adjacent to edge 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 summarizes a lecture on flat slab design and analysis. It discusses key topics such as:
1. Definitions of flat slabs and their components like column strips and middle strips.
2. Methods of analyzing flat slabs including numerical methods and manual methods like the method of substitutive beams.
3. Design considerations for flat slabs including steel distribution above columns, welded mesh reinforcement, loading schemes, and punching shear design.
4. Different types of shear reinforcement that can be used at column heads like links, cages, and bent-up bars.
This document discusses the design of two-way slabs. It defines a two-way slab as having a ratio of long to short spans less than 2, spanning in two directions. The types of two-way slabs described include flat slabs with drop panels, slabs with two-way beams, flat plates, and waffle slabs. The basic steps of two-way slab design are outlined, including choosing the slab type and thickness, the design method, calculating moments, determining reinforcement, and checking shear strength. Methods of determining maximum bending moments and slab reinforcement are also summarized.
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.
1) Two-way slabs are slabs that require reinforcement in two directions because bending occurs in both the longitudinal and transverse directions when the ratio of longest span to shortest span is less than 2.
2) The document discusses various types of two-way slabs and design methods, focusing on the direct design method (DDM).
3) Using the DDM, the total factored load is first calculated, then the total factored moment is distributed to positive and negative moments. The moments are further distributed to column and middle strips using factors that consider the slab and beam properties.
Guide to the design and construction of reinforced concrete flat slabs (1)abbdou001
This document provides guidance on the design and construction of reinforced concrete flat slabs according to Eurocode standards. It discusses factors that influence flat slab design and construction such as the type of structure, client requirements, planning rules, ground conditions, and contractor preferences. It also covers typical flat slab behavior, design considerations, construction methods, detailing, and analysis techniques. The document aims to help designers understand flat slab structural behavior and best practices for design and construction.
This document summarizes the key aspects of flat slab construction and design according to Indian code IS 456-2000. It defines flat slabs as slabs that are directly supported by columns without beams, and describes four common types based on whether drops and column heads are used. The main topics covered include guidelines for proportioning slabs and drops, methods for determining bending moments and shear forces, requirements for slab reinforcement, and an example problem demonstrating the design of an interior flat slab panel.
- The document describes the design and detailing of flat slabs, which are concrete slabs supported directly by columns without beams.
- Key aspects covered include dimensional considerations, analysis methods, design for bending moments including division of panels and limiting negative moments, shear design and punching shear, deflection and crack control, and design procedures.
- An example problem is provided to illustrate the full design process for an internal panel with drops adjacent to edge 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 summarizes a lecture on flat slab design and analysis. It discusses key topics such as:
1. Definitions of flat slabs and their components like column strips and middle strips.
2. Methods of analyzing flat slabs including numerical methods and manual methods like the method of substitutive beams.
3. Design considerations for flat slabs including steel distribution above columns, welded mesh reinforcement, loading schemes, and punching shear design.
4. Different types of shear reinforcement that can be used at column heads like links, cages, and bent-up bars.
This document discusses the design of two-way slabs. It defines a two-way slab as having a ratio of long to short spans less than 2, spanning in two directions. The types of two-way slabs described include flat slabs with drop panels, slabs with two-way beams, flat plates, and waffle slabs. The basic steps of two-way slab design are outlined, including choosing the slab type and thickness, the design method, calculating moments, determining reinforcement, and checking shear strength. Methods of determining maximum bending moments and slab reinforcement are also summarized.
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.
1) Two-way slabs are slabs that require reinforcement in two directions because bending occurs in both the longitudinal and transverse directions when the ratio of longest span to shortest span is less than 2.
2) The document discusses various types of two-way slabs and design methods, focusing on the direct design method (DDM).
3) Using the DDM, the total factored load is first calculated, then the total factored moment is distributed to positive and negative moments. The moments are further distributed to column and middle strips using factors that consider the slab and beam properties.
Guide to the design and construction of reinforced concrete flat slabs (1)abbdou001
This document provides guidance on the design and construction of reinforced concrete flat slabs according to Eurocode standards. It discusses factors that influence flat slab design and construction such as the type of structure, client requirements, planning rules, ground conditions, and contractor preferences. It also covers typical flat slab behavior, design considerations, construction methods, detailing, and analysis techniques. The document aims to help designers understand flat slab structural behavior and best practices for design and construction.
This document summarizes the key aspects of flat slab construction and design according to Indian code IS 456-2000. It defines flat slabs as slabs that are directly supported by columns without beams, and describes four common types based on whether drops and column heads are used. The main topics covered include guidelines for proportioning slabs and drops, methods for determining bending moments and shear forces, requirements for slab reinforcement, and an example problem demonstrating the design of an interior flat slab panel.
Design of flat plate slab and its Punching Shear Reinf.MD.MAHBUB UL ALAM
This document provides design considerations and an example problem for designing a flat plate slab using the Direct Design Method (DDM). It discusses slab thickness, load calculations, moment distribution, and reinforcement design for a sample four-story building with 16'x20' panels supported by 12" square columns. The design of panel S-4 is shown in detail, calculating loads, moments, and reinforcement requirements for the column and middle strips in both the long and short directions.
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.
This document discusses the design of two-way slabs. It defines a two-way slab as having a ratio of long to short spans of less than 2. The main types of two-way slabs described are flat slabs with drop panels, two-way slabs with beams, flat plates, and waffle slabs. The basic steps of two-way slab design are outlined, including choosing the slab type and thickness, the design method, calculating moments, determining reinforcement, and checking shear strength. Two common design methods are described: the direct design method which uses coefficients, and the equivalent frame method which analyzes frames cut between columns.
This document discusses the design of two-way floor slab systems. It compares the behavior of one-way and two-way slabs, describing how two-way slabs carry load in two directions versus one direction for one-way slabs. Different two-way slab systems like flat plates, waffle slabs, and ribbed slabs are described. Methods for analyzing two-way slabs include direct design, equivalent frame, elastic, plastic, and nonlinear analysis. Design considerations like minimum slab thickness are discussed along with examples calculating thickness.
This document discusses the design of floor slabs including one-way spanning slabs, two-way spanning slabs, continuous slabs, cantilever slabs, and restrained slabs. It covers slab types based on span ratios, bending moment coefficients, determining design load, reinforcement requirements, shear and deflection checks, crack control, and reinforcement curtailment details for different slab conditions. The document is authored by Eng. S. Kartheepan and is related to the design of floor slabs for a civil engineering project.
This report compares design codes for hollow block and ribbed slabs. It includes:
- A comparison of limitations between Egyptian, British, Euro and American codes on rib spacing, slab thickness, and other parameters.
- Solved examples for one-way and two-way slabs according to different codes, finding the Egyptian code most economical.
- Analysis of using one or two cross-ribs, determining one rib at midspan is sufficient.
- Different modeling methods for the slabs in structural analysis software, with minor differences in results.
- Case studies presented for one-way, cantilever, two-way hollow block slabs, and ribbed slabs using
The document discusses reinforcement in two-way slabs and footing design. It describes two types of shear failure in slabs: one-way shear and two-way shear. One-way shear results in inclined cracking and pull-out of negative reinforcement from the slab. Two-way shear can result in either inclined cracking or the slab sliding down the column. The critical perimeter for two-way shear is located at d/2 from the column face, where d is the effective depth of the slab. Formulas are provided to calculate the nominal shear resistance Vn of slabs under two-way shear with negligible moment transfer.
This presentation summarizes the key aspects of one-way slab design:
1) One-way slabs have an aspect ratio of 2:1 or greater, where bending occurs primarily along the long axis. They can be solid, hollow, or ribbed.
2) Design and analysis treats a unit strip of the slab as a rectangular beam of unit width and the slab thickness as the depth.
3) The ACI code specifies minimum slab thickness, concrete cover, span length, bar spacing, reinforcement ratios, and other design requirements.
4) An example problem demonstrates the design process, calculating loads, moments, minimum reinforcement, and checking the proposed slab thickness.
5) One-
This document discusses different types of two-way slabs, including edge-supported slabs, column-supported slabs, flat plates, and waffle slabs. It provides details on when a slab is considered a two-way slab and how it is reinforced in two directions to resist bending moments in both directions. The document also discusses analysis methods for two-way slab design.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
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 provides information on reinforcement detailing according to Eurocode 2 (EC2). It begins with an overview of the structural Eurocodes and the contents of EC2. Key topics covered in more detail include reinforcement properties, minimum cover requirements, crack control, bar spacing, bond stress calculations, and the design of anchorage and lap lengths. Worked examples are provided to demonstrate how to calculate the design anchorage length for tension reinforcement according to the equations and factors specified in EC2. In summary, the document outlines the main requirements for reinforcement detailing in concrete structures as defined by EC2.
This document discusses the design of one-way slabs. It begins by defining one-way slabs as slabs that are supported on two opposite sides and carry loads perpendicularly to the supporting beams. The document then outlines the design process, which involves analyzing representative strips of the slab as simple beams and determining reinforcement ratios. Key steps include checking deflection, calculating factored loads, drawing shear and moment diagrams, and selecting reinforcement sizes that satisfy the required ratios. Examples of one-way slab design and the minimum requirements for thickness, reinforcement ratios, and cover are also provided.
This document provides methods for designing reinforced concrete slabs using working stress design and ultimate strength design. It discusses one-way and two-way slab design, including defining characteristics, load calculations, moment calculations, depth checks, and steel calculations. Formulas are provided for slab thickness selection, elastic constant calculation, load calculations considering dead and live loads, moment determination using code coefficients, minimum steel requirements, and distribution steel spacing.
This document presents information on the design of one-way slabs. It defines one-way slabs as having a ratio of longer to shorter side of at least 2.0 and experiencing load distribution in the direction perpendicular to supports. The minimum thickness is specified in the ACI code based on span length and support conditions. Loads assigned include dead and live loads. Temperature and shrinkage reinforcement is also required perpendicular to main reinforcement to control cracking. The design procedure involves calculating minimum thickness, factored loads, moments, steel ratios, required depth and detailing of reinforcement.
This document provides an overview of design in reinforced concrete according to BS 8110. It discusses the basic materials used - concrete and steel reinforcement - and their properties. It describes two limit states for design: ultimate limit state considering failure, and serviceability limit state considering deflection and cracking. Key aspects of beam design are summarized, including types of beams, design for bending and shear resistance, and limiting deflection. Reinforcement detailing rules are also briefly covered.
Slabs are structural members that support transverse loads and transfer them to supports via bending. They are commonly used as floors and roofs. One-way slabs bend in only one direction across the shorter span like a wide beam, while two-way slabs bend in both directions if the ratio of longer to shorter span is less than or equal to 2. Design of one-way slabs involves calculating bending moment and shear force, selecting reinforcement ratio and bar size, and checking deflection, shear, and development length.
The document provides guidelines for properly detailing reinforced concrete structural elements. It discusses good detailing practices for slabs, beams, columns, and foundations to ensure structural safety and prevent failures. Proper detailing is emphasized as being essential for translating design calculations into actual construction and avoiding mistakes that could lead to collapse.
This document provides an overview of design in reinforced concrete according to BS 8110. It discusses the basic materials used - concrete and steel reinforcement - and their properties. It describes two limit states for design: ultimate limit state considering failure, and serviceability limit state considering deflection and cracking. Key aspects of beam design are summarized, including types of beams, design for bending and shear resistance, and limiting deflection. Reinforcement detailing rules are also briefly covered. Design examples are provided to illustrate bending and shear design of beams.
Designing and drawing of flat slab with the help of i.s code Sandeep Yadav
This document is a mini project report submitted by Sandeep Kumar to fulfill the requirements for a Bachelor of Technology degree in Civil Engineering. The report describes designing and drawing a flat slab structure using the Indian Standard Code. It provides an introduction to flat slab construction, advantages of flat slabs like flexibility in design and reduced building height. It also discusses code regulations, design steps, and concludes with designing a flat slab according to the IS code.
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.
Design of flat plate slab and its Punching Shear Reinf.MD.MAHBUB UL ALAM
This document provides design considerations and an example problem for designing a flat plate slab using the Direct Design Method (DDM). It discusses slab thickness, load calculations, moment distribution, and reinforcement design for a sample four-story building with 16'x20' panels supported by 12" square columns. The design of panel S-4 is shown in detail, calculating loads, moments, and reinforcement requirements for the column and middle strips in both the long and short directions.
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.
This document discusses the design of two-way slabs. It defines a two-way slab as having a ratio of long to short spans of less than 2. The main types of two-way slabs described are flat slabs with drop panels, two-way slabs with beams, flat plates, and waffle slabs. The basic steps of two-way slab design are outlined, including choosing the slab type and thickness, the design method, calculating moments, determining reinforcement, and checking shear strength. Two common design methods are described: the direct design method which uses coefficients, and the equivalent frame method which analyzes frames cut between columns.
This document discusses the design of two-way floor slab systems. It compares the behavior of one-way and two-way slabs, describing how two-way slabs carry load in two directions versus one direction for one-way slabs. Different two-way slab systems like flat plates, waffle slabs, and ribbed slabs are described. Methods for analyzing two-way slabs include direct design, equivalent frame, elastic, plastic, and nonlinear analysis. Design considerations like minimum slab thickness are discussed along with examples calculating thickness.
This document discusses the design of floor slabs including one-way spanning slabs, two-way spanning slabs, continuous slabs, cantilever slabs, and restrained slabs. It covers slab types based on span ratios, bending moment coefficients, determining design load, reinforcement requirements, shear and deflection checks, crack control, and reinforcement curtailment details for different slab conditions. The document is authored by Eng. S. Kartheepan and is related to the design of floor slabs for a civil engineering project.
This report compares design codes for hollow block and ribbed slabs. It includes:
- A comparison of limitations between Egyptian, British, Euro and American codes on rib spacing, slab thickness, and other parameters.
- Solved examples for one-way and two-way slabs according to different codes, finding the Egyptian code most economical.
- Analysis of using one or two cross-ribs, determining one rib at midspan is sufficient.
- Different modeling methods for the slabs in structural analysis software, with minor differences in results.
- Case studies presented for one-way, cantilever, two-way hollow block slabs, and ribbed slabs using
The document discusses reinforcement in two-way slabs and footing design. It describes two types of shear failure in slabs: one-way shear and two-way shear. One-way shear results in inclined cracking and pull-out of negative reinforcement from the slab. Two-way shear can result in either inclined cracking or the slab sliding down the column. The critical perimeter for two-way shear is located at d/2 from the column face, where d is the effective depth of the slab. Formulas are provided to calculate the nominal shear resistance Vn of slabs under two-way shear with negligible moment transfer.
This presentation summarizes the key aspects of one-way slab design:
1) One-way slabs have an aspect ratio of 2:1 or greater, where bending occurs primarily along the long axis. They can be solid, hollow, or ribbed.
2) Design and analysis treats a unit strip of the slab as a rectangular beam of unit width and the slab thickness as the depth.
3) The ACI code specifies minimum slab thickness, concrete cover, span length, bar spacing, reinforcement ratios, and other design requirements.
4) An example problem demonstrates the design process, calculating loads, moments, minimum reinforcement, and checking the proposed slab thickness.
5) One-
This document discusses different types of two-way slabs, including edge-supported slabs, column-supported slabs, flat plates, and waffle slabs. It provides details on when a slab is considered a two-way slab and how it is reinforced in two directions to resist bending moments in both directions. The document also discusses analysis methods for two-way slab design.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
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 provides information on reinforcement detailing according to Eurocode 2 (EC2). It begins with an overview of the structural Eurocodes and the contents of EC2. Key topics covered in more detail include reinforcement properties, minimum cover requirements, crack control, bar spacing, bond stress calculations, and the design of anchorage and lap lengths. Worked examples are provided to demonstrate how to calculate the design anchorage length for tension reinforcement according to the equations and factors specified in EC2. In summary, the document outlines the main requirements for reinforcement detailing in concrete structures as defined by EC2.
This document discusses the design of one-way slabs. It begins by defining one-way slabs as slabs that are supported on two opposite sides and carry loads perpendicularly to the supporting beams. The document then outlines the design process, which involves analyzing representative strips of the slab as simple beams and determining reinforcement ratios. Key steps include checking deflection, calculating factored loads, drawing shear and moment diagrams, and selecting reinforcement sizes that satisfy the required ratios. Examples of one-way slab design and the minimum requirements for thickness, reinforcement ratios, and cover are also provided.
This document provides methods for designing reinforced concrete slabs using working stress design and ultimate strength design. It discusses one-way and two-way slab design, including defining characteristics, load calculations, moment calculations, depth checks, and steel calculations. Formulas are provided for slab thickness selection, elastic constant calculation, load calculations considering dead and live loads, moment determination using code coefficients, minimum steel requirements, and distribution steel spacing.
This document presents information on the design of one-way slabs. It defines one-way slabs as having a ratio of longer to shorter side of at least 2.0 and experiencing load distribution in the direction perpendicular to supports. The minimum thickness is specified in the ACI code based on span length and support conditions. Loads assigned include dead and live loads. Temperature and shrinkage reinforcement is also required perpendicular to main reinforcement to control cracking. The design procedure involves calculating minimum thickness, factored loads, moments, steel ratios, required depth and detailing of reinforcement.
This document provides an overview of design in reinforced concrete according to BS 8110. It discusses the basic materials used - concrete and steel reinforcement - and their properties. It describes two limit states for design: ultimate limit state considering failure, and serviceability limit state considering deflection and cracking. Key aspects of beam design are summarized, including types of beams, design for bending and shear resistance, and limiting deflection. Reinforcement detailing rules are also briefly covered.
Slabs are structural members that support transverse loads and transfer them to supports via bending. They are commonly used as floors and roofs. One-way slabs bend in only one direction across the shorter span like a wide beam, while two-way slabs bend in both directions if the ratio of longer to shorter span is less than or equal to 2. Design of one-way slabs involves calculating bending moment and shear force, selecting reinforcement ratio and bar size, and checking deflection, shear, and development length.
The document provides guidelines for properly detailing reinforced concrete structural elements. It discusses good detailing practices for slabs, beams, columns, and foundations to ensure structural safety and prevent failures. Proper detailing is emphasized as being essential for translating design calculations into actual construction and avoiding mistakes that could lead to collapse.
This document provides an overview of design in reinforced concrete according to BS 8110. It discusses the basic materials used - concrete and steel reinforcement - and their properties. It describes two limit states for design: ultimate limit state considering failure, and serviceability limit state considering deflection and cracking. Key aspects of beam design are summarized, including types of beams, design for bending and shear resistance, and limiting deflection. Reinforcement detailing rules are also briefly covered. Design examples are provided to illustrate bending and shear design of beams.
Designing and drawing of flat slab with the help of i.s code Sandeep Yadav
This document is a mini project report submitted by Sandeep Kumar to fulfill the requirements for a Bachelor of Technology degree in Civil Engineering. The report describes designing and drawing a flat slab structure using the Indian Standard Code. It provides an introduction to flat slab construction, advantages of flat slabs like flexibility in design and reduced building height. It also discusses code regulations, design steps, and concludes with designing a flat slab according to the IS code.
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.
Experimental investigation on studying the flexural behaviour of geopolymer c...eSAT Journals
This document describes an experimental investigation on studying the flexural behavior of geopolymer concrete slabs under fixed boundary conditions. Geopolymer concrete is evaluated as an alternative to conventional cement concrete that produces lower CO2 emissions. Slabs made with geopolymer concrete were cast and tested to determine their flexural behavior under loading. Yield line theory was used to calculate the moment of resistance and maximum deflection, and test results for load-deflection behavior were compared to theoretical computations. The crack patterns from experimental testing were also compared to predicted yield line patterns for reinforced concrete slabs. Test results showed that the flexural behavior of geopolymer concrete slabs was similar to conventional concrete slabs.
The document discusses the design of two-way slabs and staircases. It provides guidance on initial proportioning of slab thickness, analysis of bending moments using code provided coefficients, design of flexural reinforcement, checking for deflection and shear limits, and detailing of reinforcement. Specific examples are presented to demonstrate the design of simply supported and torsionally restrained slab panels with reinforcement calculated and laid out. Staircases are also briefly mentioned including different types like waist slab and folded plate.
Design of reinforced flat slabs to bs 8110 (ciria 110)bmxforu
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms for those who already suffer from conditions like anxiety and depression.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
This document discusses the analysis and design of one-way and two-way concrete slabs. It describes how one-way slabs transfer loads in one direction while two-way slabs transfer loads in two perpendicular directions. The coefficient method is presented for analyzing bending moments in two-way slabs using moment coefficients from tables based on support conditions and span ratios. An example is provided to calculate moment coefficients and design a two-way slab using working stress and ultimate strength design methods.
The document provides guidelines for the design of reinforced concrete slab structures, including:
1) The effective span of a slab is the lesser of the clear span plus depth or the center-to-center distance between supports.
2) The depth of the slab depends on bending moment and deflection criteria, and can be estimated using provided formulas accounting for steel percentage and load class.
3) Loads on the slab include dead load from thickness, floor finish, and live loads ranging from 3 to 5 kN/m^2 depending on building occupancy.
This document discusses load calculation methods for building structures. It describes different types of loads including dead loads from structural elements, live loads from movable objects, and lateral loads from wind and earthquakes. It provides details on calculating dead loads for reinforced concrete slabs, including slab thickness determination using span length. An example calculation is given for the dead load per meter of a ribbed one-way slab based on the thickness, material densities, and weights of slab components like tiles, mortar, fill, and hollow blocks. The total calculated dead load for this example slab is 10.33 kN/m2.
This document discusses different types of pipes used for water conveyance, including their materials, advantages, disadvantages, and suitability. The main pipes discussed are cast iron, wrought iron, steel, galvanized iron, concrete, asbestos cement, plastic, and lead/copper pipes. Plastic pipes are now most commonly used due to being lightweight, corrosion resistant, electrically insulating, and economical. Proper laying of pipes involves preparing maps, locating the alignment, dewatering trenches, joining pipes, testing, and disinfection before use.
The document discusses the moment coefficient method for analyzing statically indeterminate structures. It provides definitions of statically indeterminate structures as those where there are more unknown reactions or internal forces than available equilibrium equations. The moment coefficient method uses coefficients provided in the ACI code that are based on elastic analysis but account for inelastic redistribution. The coefficients are multiplied by the total factored load and span length to determine bending moments. The method was first included in the 1963 ACI code and remains permissible for analyzing two-way slabs supported on all sides. Advantages include providing a more exact analysis and potential cost savings through more precise design.
This document provides information about the Structural Analysis-II course CEE-317, including the instructor details, syllabus, evaluation process, references, and an overview of exact structural analysis methods like the Moment Distribution Method. The Moment Distribution Method distributes internal forces in an indeterminate structure by satisfying equilibrium equations. It was developed in 1932 by Hardy Cross and is still widely used due to its simplicity. The document also covers structural idealization, sign convention, fixed-end moments, and the basics of stiffness and carryover factors in the Moment Distribution Method.
Urbanisation refers to the increasing proportion of people living in cities and urban areas. It began rapidly in poor countries in the mid-20th century as people migrated from rural areas to cities at a rate of 20% per year, driven by difficult rural living conditions and the concentration of jobs and services in urban centers. In rich countries, urbanisation accelerated during the Industrial Revolution as new factory and shipyard jobs drew people to towns and cities, while mechanized farming led to rural job losses. More recently, urbanisation has slowed in rich nations and some have experienced counter-urbanization, though cities are now attracting residents back to redeveloped inner areas.
This document discusses different types of intake structures used to withdraw water from sources for treatment. It describes intake structures as structures constructed at the entrance of withdrawal pipes to safely withdraw water from sources while protecting the pipes from debris. The main types discussed are submerged intakes, intake towers, structures for medium rivers, canal intakes, and intakes for dam sluice ways. Key factors in selecting intake locations like access, water quality, and flooding are also outlined.
Caissons are prefabricated hollow structures that are sunk into the ground and filled with concrete to form deep foundations. They are commonly used for bridge piers and structures over bodies of water. The process involves sinking a caisson to the desired depth using excavation methods and then filling it with concrete. Caissons carry structural loads through bell-shaped bottoms that spread the load over a wider area of soil or bedrock.
The document discusses the behavior and design of beam-columns, which are structural elements that experience both axial loads and bending moments. It covers topics such as moment connections for columns, eccentric loads on columns, interaction of axial and bending forces, and moment amplification due to axial loads. Design considerations discussed include checking for adequate strength, using interaction formulas, and verifying sufficient resistance to local buckling. The document appears to be lecture materials on structural steel beam-column design based on Canadian standards.
Caissons are large, box-like foundations that are sunk into the ground or water to transfer structural loads to deeper, stronger soil layers. There are three main types: box caissons, which are enclosed boxes opened at the top; open or well caissons, which are open at the top and bottom; and pneumatic caissons, which use compressed air to allow construction under water. Caissons are made of materials like concrete, steel, or timber and are used as foundations for bridges, dams, and other structures. Workers inside pneumatic caissons can experience health issues if not properly managed during decompression.
Fixed end moments are moments that occur at the ends of beams or other structural elements. These moments are caused by external forces or reactions that are applied at or very near the ends of the beam. Fixed end moments directly influence the maximum bending stress that will occur within the beam based on the applied loads and how they are transferred into or out of the ends of the beam.
Urbanisation (problems and suggested solutions) In ZimbabweDumisani Nhliziyo
This document discusses urbanization, including definitions, global trends, causes in Africa, and problems associated with urbanization. The major causes of urbanization in Africa are natural population increase and rural-to-urban migration driven by poverty and lack of opportunities in rural areas. Problems include unemployment, pollution, poor sanitation, disease outbreaks, traffic congestion, and increased crime. Suggested solutions are promoting rural development, improving public transportation, providing low-cost housing, encouraging the informal sector, controlling vehicle traffic, and involving communities in infrastructure planning.
Effect of modulus of masonry on initial lateral stiffness of infilled frames ...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Determination of load transfer in reinforced concrete solid slabs by finite e...IOSR Journals
This document analyzes load transfer in reinforced concrete solid slabs using finite element analysis. It models two types of slabs in SAP2000: 1) slabs with pin supports on all four edges and 2) slabs with pin supports at corners and beams along edges. For type 1, stresses are higher in the short direction but still significant in the long direction, showing load is transferred two-way. For type 2, stresses in the short direction increase with stiffer beams while stresses in the long direction decrease. The analysis concludes all concrete solid slabs behave as two-way slabs, transferring load in both directions regardless of dimensions or support conditions.
Seismic Behaviour of Reinforced Concrete Flat Plate SystemsIRJET Journal
This document summarizes a study on the seismic behavior of reinforced concrete flat plate systems compared to traditional slab structures. A six-story building located in seismic zone II is modeled in ETABS software using both flat slab and conventional slab structures. Linear static and response spectrum analyses are performed to analyze storey displacements, shears, and overturning moments under earthquake loading based on Indian standards. The results are compared to determine how each structure type performs seismically, with findings showing the flat slab structure performs better in earthquakes than the traditional slab.
This document provides a 5 PDH course on the design of folded plates. It begins with introductions and background on folded plate structures and the responsibilities of engineers. It then covers structural idealization of folded plates, the 10 step procedural analysis process, derivations of relevant formulas, preparatory work before analysis, and includes examples and figures to illustrate concepts. The document aims to describe how to analyze and design folded plates through simple hand calculations using basic principles of statics, moment distribution, and flexural theory.
1. It discusses the advantages and disadvantages of reinforced concrete as a structural material and its wide use in structures.
2. It outlines key design assumptions used in reinforced concrete design including strain compatibility between concrete and steel, stress-strain relationships of materials, and failure conditions.
3. It describes the behavior of reinforced concrete beams under increasing loads and how cracking occurs initially in the tension side before steel reinforcement engages to resist bending.
The document summarizes the planning, analysis, and design of a multispecialty hospital building. It includes the objectives to prepare architectural drawings, analyze the G+2 building using STAAD Pro, and design the building according to IS 456:2000 using the working stress method. It describes analyzing the building's ability to resist lateral loads. Maximum bending moments in beams and columns will depend on their relative rigidity. Structural elements like slabs, beams, columns, footings, and staircases will be designed according to code specifications using the working stress method.
seismic response of multi storey building equipped with steel bracingINFOGAIN PUBLICATION
1) The document analyzes the seismic response of a multi-storey reinforced concrete building equipped with different steel bracing systems.
2) A 7-storey building model was created and linear analysis was conducted to compare the responses of an unbraced building model and models with X, V, and inverted V bracing systems.
3) The results showed that all bracing systems reduced displacement, drift, shear forces, and bending moments compared to the unbraced building, with the X bracing system providing the largest reductions in structural response.
Flat slabs were originally invented in the U.S. in 1906 and load tested between 1910-1920. They are reinforced concrete slabs supported by columns without beams. Flat slabs offer advantages like reduced construction costs, faster construction, and greater architectural freedom. They are classified as solid flat slab, solid flat slab with drop panels, solid flat slab with column heads, or banded flat slab. Analysis and design of flat slabs involves distributing moments from equivalent frame analysis to slab components and checking shear and punching resistance.
IRJET- Effect of Relative Stiffness of Beam-Column Joint on Internal Forces i...IRJET Journal
This document discusses the effect of relative stiffness of beam-column joints in reinforced concrete structures. It presents research analyzing the behavior of partially restrained beam-column connections using the STAAD.Pro software. The study varies the grade of concrete to change the relative stiffness of the joint and observes the impact on internal forces. It calculates section properties and compares results from two methods - considering the full cross-sectional area versus accounting for the moment of inertia of steel reinforcement. The objectives are to study how relative joint stiffness and concrete/steel properties affect flexural and compressive strengths.
Evaluation of rigid pavements by deflection approacheSAT Journals
This document discusses using the Benkelman Beam Deflection (BBD) technique to evaluate rigid pavements by measuring load transfer efficiency (LTE) across joints. The BBD technique involves using two Benkelman beams placed on adjacent slabs - one loaded and one unloaded - to measure deflections when a load passes over. LTE is calculated as the ratio of the unloaded slab deflection to loaded slab deflection. The document applies this method to a rigid pavement in Pune, India, finding LTE values ranging from 31-43% across slabs, with a characteristic LTE of 37.11%. It concludes the BBD technique can provide information on dowel bar performance in rigid pavements.
1. Seismic design involves careful planning, analysis, detailing, and construction to create earthquake-resistant structures.
2. Key steps in planning include making the building symmetrical, avoiding weak stories, selecting good materials, and following code provisions.
3. Design considerations are analyzing structural elements, avoiding weak columns and strong beams, using shear walls and bracing, and designing for increased forces in soft stories. Ductility is increased through design and material choices.
1. Seismic design involves careful planning, analysis, detailing, and construction to create earthquake-resistant structures.
2. Key steps in planning include making the building symmetrical, avoiding weak stories, selecting good materials, and following code provisions.
3. Design considerations are analyzing structural elements, avoiding weak columns and strong beams, using shear walls and bracing, and designing for increased forces in soft stories. Ductility is increased through design and material choices.
1. Seismic design involves careful planning, analysis, detailing, and construction to create earthquake-resistant structures.
2. Key steps in planning include making the building symmetrical, avoiding weak stories, selecting good materials, and following code provisions.
3. Important aspects of design are analyzing structural elements to resist seismic forces, using techniques like shear walls and bracing, and ductile detailing of reinforcement.
4. Careful construction with quality materials and workmanship is also vital for seismic resistance.
This document discusses the course CV706 Advanced Design of Concrete Structures. The course covers the analysis and design of various reinforced concrete structural elements including continuous beams and frames, slabs, grid slabs, folded plates, bunkers, silos, deep beams, corbels, and pile caps. Specifically, it will discuss the redistribution of moments in continuous beams and frames, yield line analysis for slab design, and the analysis and design of elements like grid slabs, filler slabs, folded plates, bunkers, silos, deep beams, corbels, and pile caps. The course will also review the limit state design method.
Analysis and Design of Composite Beams with Composite Deck Slab.docxAdnan Lazem
This document presents an overview of the theory and design of composite beams with steel decks according to the AISC Specification. It discusses general considerations for composite beam design including that it is most efficient for heavy loading and long spans. It also summarizes provisions for fully and partially composite beams, requirements for shored and unshored construction, and considerations for end reactions, deflection, use of different material strengths, and use of cover plates.
Analysis and Design of Mono-Rail Plate Girder Bridge_2023.docxadnan885140
This document provides an overview and summary of a graduation project analyzing and designing plate girders. It includes an abstract stating the objectives are to develop an understanding of plate girder analysis and design principles and incorporate them into a computer program. The project is divided into 5 chapters: introduction to plate girders, literature review, theoretical basis using stiffness matrix analysis, description of the computer program developed, and conclusions/recommendations. It also provides the table of contents and beginning of Chapter 1 which gives a general introduction to plate girders, their typical sections, and uses in construction.
Use of flat slabs in multi storey commercial building situated in high seismi...eSAT Publishing House
This document discusses a study that compares the behavior of multi-storey commercial buildings with flat slab construction and conventional reinforced concrete frame construction. Six building models are analyzed: conventional RC frame and flat slab buildings with heights of 4, 9, and 13 stories. The models are analyzed using ETABS software to study parameters like lateral displacement, storey drift, storey shear, column moments and axial forces, and time period under different load conditions. The analysis is done for Seismic Zone IV. The study aims to better understand the seismic behavior of flat slab buildings and identify design improvements needed for their performance in high seismic zones.
The document summarizes the analysis and design of a G+3 shopping complex. It includes the design of structural elements like slab, beams, columns, staircase and foundation. It describes the design methodology, software used for analysis (STAAD.Pro), and design of key structural components like the ground floor slab. The students have submitted this project to fulfill the requirements for their Bachelor of Technology degree in Civil Engineering.
The document summarizes the analysis and design of troughed floors according to Eurocode. It introduces troughed floors as slabs that combine the advantages of ribbed floors and flat slabs, providing efficient long-span floors up to 12m. It describes the components of troughed floors and provides equations to size the elements and estimate self-weight. The analysis is carried out using coefficients for one-way slabs and beams. The design considers flexure and shear of the ribs and beams according to Eurocode 2. A worked example is included to demonstrate the complete design of a troughed slab and supporting beam.
2. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
Abstract
Reinforced concrete slabs are used in floors, roofs and walls of buildings and as the decks of
bridges. The floor system of a structure can take many forms such as in-situ solid slab, ribbed
slabs or precast units. Slabs may span in one direction or in two directions and they may be
supported on monolithic concrete beams, steel beams, walls or directly by the structure’s
columns. In this user guide, some common design methods, general assumptions and
considerations for one-way slabs and two-way slabs will be introduced. Typical demonstrations
will be shown. It will illustrate the programs with some concrete examples. The basic input
requirements and output characteristics of programs will be also introduced in this user guide.
Table of Content
2.1 Introduction to Slab Systems ....................................................................................... 4
2.1.1 Types of slab................................................................................................ ...... 4
2.1.2 Design Methods ................................ ................................ ................................ . 5
2.1.3 General design considerations and assumptions.................................................. 6
2.1.4 Resistance Moment of Solid Slabs................................................................ ...... 7
2.1.5 Resistance Moment of Solid Slabs................................................................ .... 10
2.1.6 Design algorithm.............................................................................................. 11
2.2 R.C. Slab Systems Design Examples ................................ ................................ .......... 13
2.2.1 Design for One-way Slab ................................ ................................ ................. 14
2.2.2 Design for Two-way Slab................................ ................................ ................. 19
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3. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
Figures
Figure 1 - One-way slab on beams and girders ................................ ................................ .......... 7
Figure 2 - Design procedure for one-way slab design. ................................ ............................. 11
Figure 3 - Design procedures for two-way design................................................................ .... 12
Figure 4 - Loading input interface for slab systems design................................. ...................... 15
Figure 5 – Choose different location................................ ................................ ........................ 16
Figure 6 – Selection of distribution steel reinforcement ........................................................... 16
Figure 7 – Selection of tensile steel reinforcement................................ ................................... 17
Figure 8 - Results of moment resistance for one-way slab. ................................ ...................... 18
Figure 9 - Loading input interface for slab systems design................................. ...................... 20
Figure 10 – Choose different connection condition for two-way slab....................................... 21
Figure 11 - Selection of distribution steel reinforcement................................ .......................... 22
Figure 12 – Selection of tension steel reinforcement of resisting moment 1 ............................. 23
Figure 13 – Confirmation of reinforcements in different locations ........................................... 24
Figure 14 – View reinforcement for resisting moment in different locations ............................ 25
Figure 15 – Calculation of reinforcement for resisting moment 4................................ ............. 26
Tables
Table 1 – Comparison between one-way and two-way slab ....................................................... 4
Table 2 - Ultimate bending moment and shear forces in one-way spanning slab ........................ 7
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4. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.1 Introduction to Slab Systems
2.1.1 Types of slab
Slabs are plate elements forming floors and roofs in buildings which normally carry uniformly
distributed loads. Slab may be simply supported or continuous over one or more supports and are
classified according to the method of support as follows:
1. Spanning on way between beams or walls
2. Spanning two ways between the support beams or walls
3. Flat slabs carried on columns and edge beams or walls with no interior beams
Slabs may be solid of uniform thickness or ribbed with ribs running in one or two directions.
Slabs with varying depth are generally not used. In this application, one-way and two-way solid
slabs are discussed.
Determination of slab type depends on the ratio of length of longer side to that of shorter side.
The comparison between one-way and two-way slab is shown in Table 1.
One-way slab Two-way slab
Symbol
ly/lx >2 ≤2
Distribution of reactions
on to supports
Table 1 – Comparison between one-way and two-way slab
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5. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.1.2 Design Methods
Slabs may be analyzed using the following methods:-
1. Elastic methods
It covers three techniques.
a) Idealization into strips or beams spanning one way or a grid with the strips spanning two
ways.
b) Elastic plate analysis.
c) Finite element analysis. It is the best method for irregularly shaped slabs or slabs with
non-uniform loads.
2. Method of design coefficients
The moment and shear coefficients are selected from the code, which have been obtained from
yield line analysis
3. Yield line method
The yield line method is a powerful procedure for the design of slabs. It is an ultimate load
method of analysis that is based on plastic yielding of an under-reinforced concrete slab section.
For the details of the theory and yield line analysis, please refer to “MacGinley, T.J., and Choo,
B.S., Reinforced Concrete: Design Theory and Examples, 2nd edition, E & F N Spon, London,
1990.”
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6. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.1.3 General design considerations and assumptions
1) Uniformly loaded slabs
Slabs carrying predominantly uniform load are designed on the assumption that they consist of a
series of rectangular beams 1 m wide spanning between supporting beams or walls.
2) Arrangement of loads
Although the code states that in principle the slab should be designed to resist the most
unfavorable arrangement of loads, usually it is only necessary to design for the single-load case
of maximum design load on all spans or panels. Design load = 1.4G k + 1.6Q k This is permitted
subject to the following conditions:
• The area of each bay exceeds 30 m2.
• The ratio of characteristic imposed load to characteristic dead load does not exceed 1.25.
• The characteristic imposed load does not exceed 5kN/m2 excluding partitions.
3) Shear
Shear stresses are usually low, except where are heavy concentrated loads. But in my FYP, only
uniform distributed loads (including dead load and live load) are considered so that there is not
any shear reinforcement will be considered.
4) Distribution reinforcement
The functions of distribution reinforcement are typing the slab together, distributing non-uniform
loads through slabs and taking the possible bending moments in the long span.
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7. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.1.4 Resistance Moment of Solid Slabs
2.1.4.1 One-way Solid Slabs
The Figure 1 shows the typical one-way slab.
Figure 1 - One-way slab on beams and girders
Slabs behave primarily as flexural members and design of the cross-section is similar to beams.
Breadth is fixed since a unit value of one meter is normally used in calculations. The design
ultimate moment and shear force are given in Table 2 here.
One important note should be mentioned here is 20% redistribution is allowed when using the
table.
End support/slab connection
Simple Continuous At first Middle Interior
interior interior supports
At outer Near middle At outer Near middle
support spans
support of end span support of end
support
Moment 0 0.086FL -0.04FL 0.075FL -0.086FL 0.063FL -0.063FL
Shear 0.4F -- 0.46F -- 0.6F -- 0.5F
Note: F is the total design ultimate load ( 1.4G k + 1.6Qk )
L is the effective span
Table 2 - Ultimate bending moment and shear forces in one-way spanning slab
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8. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.1.4.2 Two-way Solid Slabs
The design of two-way slab presents varying degrees of difficulty depending on the boundary
conditions. General, there are two types of two-way slab:
• Simply supported slabs
• Restrained slabs
When a slab is supported on all four of its sides it effectively spans in both directions, and it is
sometimes more economical to design the slab on this basis. The amount of bending in each
direction will depend on the ratio of the two spans and the conditions of restraint at each support.
Moment in each direction of span are generally calculated using coefficients which are tabulated
in the codes of practice. Areas of reinforcement to resist the moments are determined
independently for each direction of span.
2.1.4.2.1 Simply supported slabs
A slab simply supported on its four sides will deflect about both axes under load and the corners
will tend to lift and curl up from the supports, causing torsional moments. When no provision
has been made to prevent this lifting or to resist the torsion then the moment coefficients
( α sx , α sy ) may be used and the maximum moments are given by:
m sx = α sx nl x
2
in direction of span l x
m sy = α sy nl y in direction of span l y
2
Where msx and msy are the moments at mid-span on strips of unit width with spans lx (the length
of longer side) and ly (the length of shorter side) respectively. And n is the total ultimate load per
unit area: n = (1.4G k + 1.6Qk )
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9. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
The value of the moment coefficients are derived from the following equations:
ly ly
( )4 ( )2
lx lx
α sx = α sy =
ly ly
81 + ( ) 4 81 + ( ) 4
lx lx
The area of reinforcement in direction l x and l y respectively are
m sx m sy
Asx = Asy = (per meter width)
0.95 f y z 0.95 f y z
2.1.4.2.2 Restrained slab spanning in two direction
When the slabs have fixity at the supports and reinforcement is added to resist the maximum
moments per unit width are given by
m sx = β sx nl x in direction of span l x
2
m sy = β sy nl y in direction of span l y
2
Where β sx and β sy are the moment coefficients and n is the total ultimate load per unit area:
n = (1.4G k + 1.6Qk ) .
β y = (24 + 2 N d + 1.5 N d )1000
2
Nd is the number of discontinuous edges
2 l
γ = {3 − 18 x [ β y + β 1 + β y + β 2 ]}
9 ly
γ = β x + β3 + β x + β4
Note: β 1 and β 2 take values of 4 / 3β y for continuous edges or zero for discontinuous edges.
β 3 and β 4 take values of 4 / 3β x for continuous edges or zero for discontinuous edges.
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10. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
The area of reinforcement in direction l x and l y respectively are
m sx m sy
Asx = Asy = (per meter width)
0.95 f y z 0.95 f y z
2.1.5 Resistance Moment of Solid Slabs
The theories and procedures regarding shear reinforcement design of the cross-section are
similar to beams. It would not repeat here. The maximum shear force per unit width are given by
v sx = β sx nl x in direction of span l x
v sy = β sy nl y in direction of span l y
Shear reinforcement ratio:
Asv bv (v − v c )
=
Sv 0.95 f yv
And the maximum spacing of stirrups in the direction of span is less that 0.75 times the depth of
the beam. It makes sure that at least one link intercepts a diagonal crack. The area of shear
reinforcement in slabs depends on the value of applied shear stress. For details, please refer to
BS8110: Part 1, Table 3.16 (Form and area of shear reinforcements in solid slabs).
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11. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.1.6 Design algorithm
This section will focus on the discussion of design algorithm for slab systems design including
design for one-way and two-way slab.
2.1.6.1 One-way Slab System Design
In one-way slab design, calculation of steel reinforcement for resisting bending moment is very
similar to the beam design. In the beam design, shear links arrangement was also considered. But
in one-way slab, we assume that there is no shear link in the slab system. Actually, we still check
the shear resistance. When the shear stress is larger than the concrete shear resistance, the slab
will fail in shear.
Figure 2 - Design procedure for one-way slab design.
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12. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.1.6.2 Two-way Slab System Design
In two-way slab analysis, the support condition will affect loading and bending factors. In order
to find the ratio, a database should be set up which contain those values. Computer will find out
the ratio from the database. After the ratio is determined, the calculation is very much similar to
the beam design. So the design procedure will follow the beam design.
Figure 3 - Design procedures for two-way design
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13. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.2 R.C. Slab Systems Design Examples
The user guide provides a few typical examples for slab systems design. More concrete examples
with different slab types, such as one-way and two-way slab, and assumptions are available at:
http://bccw.cityu.edu.hk/rc.design/example.asp. The completed list of examples is listed as
follows.
R.C. Slab Systems Design Examples
Example Assumptions/Situations
• One-way spanning solid slab
• Continuous slab
1
• Equal spans
• Two-way spanning solid slab
• Simply supported
2
• No provision to resist torsion at the corners
• Two-way spanning solid slab
• Restrained edge
3
• Corner portion
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14. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.2.1 Design for One-way Slab
2.2.1.1 Input
In this section, a typical example for one-way slab design is shown. Reader may follow the
detailed procedures.
Example 1
A continuous one-way slab has three equal
spans of 3.5 meter each. The slab depth is
assumed to be 140mm. The loading is as
3.5m
followings:
Dead load (including self-weight, screed, finish,
10m
partitions, ceiling) = 5.2 kN/m2
Imposed load = 3.0 kN/m2
The construction materials are Grade 30
concrete and Grade 460 reinforcement. The
conditions of exposure are mild and the cover
required is 25mm. Design the reinforcement for
the positions of near middle point end span
and middle interior span.
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15. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
Detail Procedures
1. Input basic parameters, such as include loads, sections properties, etc.
2. Chick “Submit” when you finish inputting basic parameters. (See Figure 4)
3. Select different location of slab connection. (See Figure 5)
4. Select an appropriate value of distribution reinforcement. In this example, 223mm2 is
chosen. (See Figure 6)
5. Select an appropriate value of tension/compression reinforcement. In this example,
335mm2 of tension reinforcement is chosen.
6. Chick “Submit” when you finish choosing areas of reinforcement. (See Figure 7)
In this example, since the dead load includes self-weight, screed, finish, partitions and ceiling,
therefore, zero value should be inputted for the density of slab. After entering the design
parameters, click the “Submit” button to proceed to the next step – selection of slab connection.
Figure 4 - Loading input interface for slab systems design.
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16. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
Figure 5 – Choose different location
Users may assign appropriate area of reinforcement by selecting from the table in the “Areas of
groups of bars” section or defining at the “User Define” section. The required and maximum
areas of tension reinforcement are shown at the top of the window as shown in Figure 6. In this
example, 182mm2 is required and 223mm2 is chosen. After selecting distribution reinforcements,
then go to selection of tension / compression reinforcements.
Figure 6 – Selection of distribution steel reinforcement
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17. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
The required and maximum areas of tension reinforcement are shown at the top of the window as
shown in Figure 7. In this example, 243mm2 is required. After selecting reinforcements, then
chick the “Submit” bottom.
Figure 7 – Selection of tensile steel reinforcement
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18. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.2.1.1 Output
The application will show the results quickly. Numerical result and graphical output can be
shown in the output part. The section properties and design loadings are displayed at the top of
reinforcement calculation. The detailed calculations, including K value, tension and compression
reinforcement and checking of shear resistance are also displayed. A typical output is shown in
Figure 8.
Figure 8 - Results of moment resistance for one-way slab.
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19. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.2.2 Design for Two-way Slab
2.2.2.1 Input
In this section, a typical example for one-way slab design is shown. Reader may follow the
detailed procedures.
Example 2
A part floor plan for an office building measuring 6m
x 6m. (As shown in the right hand side) It consists of
restrained slabs poured monolithically with the edge
beams. The slab is 175mm thick and the loading is as
6m
follows:
Total dead load = 6.2 kN/m2
Imposed load = 2.5 kN/m2 6m
Design the corner slab using Grade 35 concrete and
Grade 460 steel reinforcement.
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20. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
Detail Procedures
1. Input basic parameters, such as include loads, sections properties, etc.
2. Chick “Submit” when you finish inputting basic parameters. (See Figure 9)
3. Select different location of slab connection. (See Figure 10)
4. Select an appropriate value of distribution reinforcement. In this example, 223mm2 is
chosen. (See Figure 11)
5. Chick “Submit” when you finish choosing areas of reinforcement.
6. Select an appropriate value of tension/compression reinforcement for resisting moment
1 (m1), moment 2 (m2), moment 3 (m3), moment 4 (m4), moment 5 (m5) and moment
6 (m6). (See Figure 12)
7. Chick “Confirm” when you finish choosing areas of reinforcement for different location.
In this example, since the dead load includes self-weight, screed, finish, partitions and ceiling,
therefore, zero value should be inputted for the density of slab. After entering the design
parameters, click the “Submit” button to proceed to the next step – selection of slab connection.
Figure 9 - Loading input interface for slab systems design.
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21. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
There are two types of two-way slab, which includes: simply supported slab and restrained slabs.
When considering restrained slabs, user may need to determine the continuity condition of the
four edges.
Figure 10 – Choose different connection condition for two-way slab
There are nine type of panel are considered:
• Interior panels
• One short edge discontinuous
• One long edge discontinuous
• Two adjacent edges discontinuous
• Two short edges discontinuous
• Two long edges discontinuous
• Three edges discontinuous (one long edge continuous)
• Three edges discontinuous (one short edge continuous)
• Four edges discontinuous
CITY UNIVERSITY OF HONG KONG 21
Department of Building and Construction
22. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
Selection of distribution steel reinforcement is shown in Figure 11. In this example, 251mm2 is
chosen., and then chick “Submit”.
Figure 11 - Selection of distribution steel reinforcement
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Department of Building and Construction
23. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
Users may assign appropriate area of reinforcement by selecting from the table or defining by
themselves. The required and maximum areas of tension reinforcement are shown at the top of
the table.
Figure 12 – Selection of tension steel reinforcement of resisting moment 1
CITY UNIVERSITY OF HONG KONG 23
Department of Building and Construction
24. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
Summary will be displayed after selection of steel reinforcement, please chick “Confirm” if there
is no any mistake.
Figure 13 – Confirmation of reinforcements in different locations
CITY UNIVERSITY OF HONG KONG 24
Department of Building and Construction
25. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
2.2.2.2 Output
After selecting reinforcements in different location, designer can view the detailed calculation of
reinforcement in each location. In this case, there are six locations, they are from m1 to m6
according to Figure 14.
For example, suppose that the user want to view the calculation for resisting moment 4, than
select “Moment 4” and then chick “View Detailed Calculation”. The detail calculation is
displayed the page. See Figure 14 and Figure 15.
Figure 14 – View reinforcement for resisting moment in different locations
CITY UNIVERSITY OF HONG KONG 25
Department of Building and Construction
26. Web-Based Reinforced Concrete Design (Part II): R.C. Slab Systems Design
Figure 15 – Calculation of reinforcement for resisting moment 4
CITY UNIVERSITY OF HONG KONG 26
Department of Building and Construction