Design of reinforced concrete structures ii twoway slabs 1 1. Both methods use the same procedure to divide the moments so found between the middle strip and column strips of the slab and the beams if any. For this reason, some supplemental design guidance is provided when practical and technically justified. Asce, secb course content slab on grades construction. Design of one way slabs as per is 456 worked step by step. Reinforced concrete design 1 design of slab examples and. The bearing capacity increased by combining all individual footings in to one mat since bearing capacity. The integral wearing surface is considered in the weight calculations.
The second alternate procedure for determining reinforcement is the computation of the percent. Pdf design procedure of column footings foundation design. What should be the design procedure for designing a flat. Reinforced concrete slab design using the empirical method bridgesight solutions for the aashto lrfd bridge design specifications bridgesight software tm creators of effective and reliable solutions for the worlds bridge engineers 2688 venado way rescue, ca 95672 phone. Manual for design and detailing of reinforced concrete to the september 20 code of practice for structural use of concrete 20 2. Pdf design procedure of column footings foundation. Here are the steps for the design procedure for one way slab in steps.
Design of masonry short and long walls, columns and retaining walls. Calculate aspect ratio aspect ratio 2 longer spanshorter span 2. How to design a flat slab, step by step explained in this video. Flat slab system is an important division of concrete floor system.
At ground floor, slabs are not provided and the floor will directly rest on ground. What are the design requirements of concrete slab design. Draw maximumminimum ultimate load bending moment envelope after redistribution. It is recommended that for culverts with spans over 3. Determine the thickness of the slab panel using previous article. Floor slabs can range from a simple residential basement slab to a heavyduty industrial floor. Rectangular beams and oneway slabs page 5 of 9 maximum permissible steel ratio, max an overreinforced beam will fail in a brittle manner while an underreinforced beam will. Twoway slab analysis and design using elastic frame method efm efm as known as equivalent frame method in the aci 318 is the most comprehensive and detailed procedure provided by the csa a23. Design of one way slabs as per is 456 worked step by. Before going to this topic, please read it there are two types of slab. Oneway and twoway slabs oneway slabs transfer the imposed.
In general, the design of slab become more simpler because compression reinforcement are often not required and the shear stress are usually low except when there are heavy concentrated load. Thus, the maximum reinforcement ratio corresponds to a net tensile strain in the. Manual for design and detailing of reinforced concrete to the. Must watch basics of flat slab for better understanding from the link given below. Design of slab examples and tutorials by sharifah maszura syed mohsin. A civil engineer must know all the aspects regarding the flat floor system. A procedure for carrying out the detailed design of slabs is shown in table 1.
Design step 4 design of deck prestressed concrete bridge design example task order dtfh6102t63032 43 for this example, a slab thickness of 8 in. Manual for design and detailing of reinforced concrete to. It is used where the supporting soil has low bearing capacity. A slab strip of unit width is analysed using simple beam theory. Carry out analysis step 2 moment envelope sk 29 typical moment envelope of a continuous beam.
Assume partitions cannot be damaged by deflections. Select representative 1 m wide design stripstrips to span in the short direction, as shown in figure 8. Twoway joist concrete slab floor waffle slab system. Following are the rcc slab design and detailing guidelines. Flat slab analysis, design and detailing pdf civil engineering. The construction and design of concrete slabs on grade d. Before going to this topic, please read it there are two types of slab classification based on the direction of bending occurs in these slabs. The procedure of the design of oneway slab is the same as that of beams. Design procedure of twoway slabs using aci moment coefficients. Mat or raft foundation is a large concrete slab supporting several columns in two or more rows. The two classifications are oneway slab and twoway slab. The results of the study show that the slab can be successfully used for residential buildings as it meets all the requirements and demands fewer materials.
Reinforced concrete slab design and detailing guidelines for depth of slab, loads on slab, reinforcement guide for oneway and twoway. One way slab being supported on two opposite sides only leads to the structural action in single direction. Here, we have tried to gather various reading materials available in the web about flat slab floor system in one place. These materials are originally located at different websites. We are goings to learn what are design requirements of concrete slab design as per standard is codes. Oneway solid slabs are designed as rectangular sections subjected to shear and moment. Concrete design procedures generally follow the strength design method contained in aci318, although certain aspects of the procedures may be considered conservative relative to conventional residential foundation applications.
Dec 14, 2017 design of one way slab is covered in this video. Bending will take place in the two directions in a dishlike form. Chapter 3 design of rectangular beams and oneway slabs. Reinforced concrete slab design using the empirical method. The lateral loads are independently resisted by shear walls. Figure 1 illustration of sub slab probe design components of the subslab probe. Accordingly, main reinforcement is required in the two directions. Design procedure steps for one way slab slab design steps.
Pdf 3 analysis and design of deck slab satya narayana. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan. Chapter 18 concrete slab structures january 2019 188 18. How to design concrete structures using eurocode 2. Chapter 3 design of rectangular beams and oneway slabs 12. Step 3 shear envelope max sk 210 typical shear envelope of.
Chapter 3 design of rectangular beams and oneway slabs 12 h a 12 strip in a simply supported one way sl ab h. Design of reinforced concrete structures ii twoway slabs. After this publication, it was subsequently adopted by the uniform building. Design of short and long columns with axial and eccentric loading, design of isolated column footing. A flat slab is a reinforced concrete slab supported directly by concrete columns without the. Therefore, only ground beams passing through columns are provided as tie beams. A design procedure for carrying out detail design of slab may be list out as follows. Distribute moments transverse at critical sections to. Distribute moments transverse at critical sections to column and middlestrip and if.
Design is defined as the decisionmaking process of planning, sizing, detailing, and developing specifications preceding construction of slabs onground. Flat slab analysis, design and detailing pdf civil. Reinforced concrete design 1 design of slab examples. The slab has to carry a distributed permanent action of 1. The concrete floor slab system shown below is for an intermediate floor to be designed. The design procedure set forth in that publication had at that time been in use by the author for about 15 years. Reinforced concrete slab design and detailing guidelines for depth of slab, loads on slab, reinforcement guide for oneway and twoway slabs as per is 456. Example design combinations for deflection quasipermanent derived for.
Use i wsd, ii usd to design the twoway slab shown below, carrying floor finish 30 psf, random wall 50 psf and live load 60 psf given. For those who do not know what are the des ign requirements of a slab. Information on other aspects, su ch as materials, construction methods, placement of concrete, and finishing techniques, is. Design of rectangular beams and oneway slabs continued. Design example of a six storey building iit kanpur. Analysis and design of continuous slab and beam footing ubani obinna u. Twoway concrete floor slab with beams design and detailing. In any span, the max cable sag, zd depends on the concrete cover requirements and the tendon dimensions. The intent of this handbook is to provide a design procedure which could be used in. Design of slab examples and tutorials by sharifah maszura syed mohsin example 1. Designing of slabs depends upon whether it is a oneway or a two way slab, the end conditions and the loading.
A combination of these values will determine the slab stresses at the time of stressing and at service loads. The bearing capacity increased by combining all individual footings in to one mat since bearing capacity is proportional to width and depth of foundations. The construction and design of concrete slabs on grade. Design procedure the basic design procedure of a twoway slab system has five steps.
For the design of slabs, there are some requirements or precautions taken before starting the design procedure as per the is code. One way slab design how to design one way slab daily civil. The main objective of this project is to analyze and design a multistory building 3ddimensional reinforce concrete frame, the design of reinforced concrete slabs, beams, columns, footings and. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types. Reinforced concrete slab design and detailing guide is456.
M ed is that part of the unbalanced slab bending moments that is transferred into the column at the support. Introduction concrete slabs on grade are a very common type of concrete construction. Oneway slabs normally design as a beam with cables running in the direction of the span at uniform centres. Therefore, the objective of this report was to develop and document the procedures for designing flat slab structures. Twoway flat plate concrete floor system design structurepoint. Step 2 design forces draw panel of slab and indicate maximum design moments, shears and in. There are two types of slab classification based on the direction of bending occurs in these slabs. Find depth of slab using deflection control criteria. The following limitations apply to the slab system. There must be at least 3 continuous spans in each direction viz column strip, middle strip, column strip the panels should be rectangular and the ratio of longer. Basic procedure of structural design the structural world. Oneway spanning slabs should be treated as beams of unit width and chapter 2 should be followed except for minimum shear reinforcement. Calculation of approximate depth from deflection criteria cl 23. A2 slab thickness design by wri method a3 design examples using coe charts a4 slab design using posttensioning a5shrinkagecompensatingconcreteexamples chapter lintroduction l.
Twoway joist concrete slab floor waffle slab system analysis and design design the concrete floor slab system shown below for an intermediate floor with partition weight of 50 psf, and unfactored live load of 100 psf. Simply supported one way slab a rectangular reinforced concrete slab is simplysupported on two masonry walls 250 mm thick and 3. A2slab thickness design by wri method a3design examples using coe charts a4slab design using posttensioning a5shrinkagecompensatingconcreteexamples chapter lintroduction l. Slabs are usually used in floor and roof construction.
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