Download two way slab design excel sheet template for free. The coefficient method may be the simplest, easiest and the quickest approach for the design of two way slab supported by edge beam on all slab sides. The solution per ddm can be found in the twoway plate concrete floor system design example. The proposed slab system must meet the current code. A oneway slab has momentresisting reinforcement only in its short axis, and is used. A civil engineer must know all the aspects regarding the flat floor system. They may be supported on two opposite sides only fig. View test prep concrete 3 design of concrete beam and slab twoway slab part 22 from engineerin 101 at royal melbourne institute of technology. Designing of slabs depends upon whether it is a oneway or a two way slab, the end conditions and the loading. No redistribution is allowed when method 1 or method 2 of analysis in section 3. 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.
Chapter 3 design of rectangular beams and oneway slabs 12. A civil engineer should study these lectures and materials for structural engineering acumen. The slab has to carry a distributed permanent action of 1. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems. Two way slab design based on aci 31811 using finite element method. Two way flat plate concrete floor system analysis and design the concrete floor slab system shown below is for an intermediate floor to be designed considering partition weight 20 psf, and unfactored live load 40 psf. Posttensioned oneway slab pennsylvania state university. Here, we have tried to gather various reading materials available in the web about flat slab floor system in one place.
Pdf analysis of two way ribbed and waffle slabs with. This document was uploaded by user and they confirmed that they have the. The redesign of the residences compared a two way concrete slab twcs design to a one way concrete slab owcs design. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. The reinforced concrete design manual sp1711 is intended to provide guidance and assistance to professionals engaged in the design of castinplace reinforced concrete structures. In two way slab, the ratio of longer span l to shorter span b is less than 2. Flat slab analysis, design and detailing pdf civil. If the ratio of longer dimension of the slab panel to the shorter dimension is greater than or equal to 2 then it is designed as one way slab. Two way edgesupported slabs two way edgesupported slabs.
Two layers of steel bar reinforcement are needed for secondary containment floors because tank loads induce both positive and negative bending moments in the floor. Example design of two way edgesupported solid slab. The explicit transverse torsional member method is found to give good results for drifts and slab beam actions, and is recommended for analysis and design of two way slab systems under combined. Design of slab two way excel sheet design spreadsheets the specified design strength of the concrete, is 25 mpa and the specified yield strength of the reinforcement, fy, is 400 mpa. Panel edge conditions analysis and design of slabs two way. Such a grid of beams reduces the span of the slab and thus permits the designer to reduce the slab thickness. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Design of one way slabs as per is 456 worked step by step limit state design.
Waffle slab analysis and design is similar to the procedure used with flat plates except that special considerations need to be taken into account to reduce the complexity of calculations needed when using exact geometry of the twoway joists. Slab moments calculated by various slab analysis methods are compared with each other for idealized flatplate and two way slab onbeam structures. Design of a two way rcc slab structural engineering. Beams of width and depth are provided on all column lines. Ce 433, fall 2006 slab design example 1 6 design a one way slab for an exterior bay of a multistory office building using the information specified below. At ground level, the floor beams fb are not provided, since the floor directly rests on ground earth filling and 1. Load paths, one and two way slabs structural concepts and design duration. Two way concrete floor slab with beams design and detailing design the slab system shown in figure 1 for an intermediate floor where the story height 12 ft, column crosssectional dimensions 18 in. The basic design procedure of a two way slab system has five steps. The two classifications are one way slab and two way slab. Member design reinforced concrete two way spanning slab bs8110 v2015. Best practices of concrete pavement transition design and construction by youn su jung graduate assistant research texas transportation institute dan g.
Time saving design aids two way slabs page 1 of 14 the following example illustrates the design methods presented in the article timesaving design aids for reinforced concrete, part 2. This condition occur when the slabs are connected monolithically with support. Bending will take place in the two directions in a dishlike fo. Design of reinforced concrete structures ii two way slabs 1 1.
The owcs was able to be integrated with the existing architectural design with minor architectural impact. All available load test results indicated that the flat plate or flat slab was a most efficient design with an adequate safety factor. The program is developed around the robust computational core of two popular programs ptdata. However, the design example in chapter 10 includes calculations. That means at any point the slab is curved in both direction. Twoway slabs structural engineering forum of india, sefi. Two way slab design by direct design method as per aci 31811. Design of a two way rcc slab structural engineering forum. A monolithic reinforced concrete floor is to be composed of rectangular bays measuring, as shown. Oneway and twoway slabs university of asia pacific. My graduation project with my mate ghassan faris, a two way ribbed slab of clear span of 18 x 25 m was designed by safe 2014, the building is 3storey concrete. The numbering of the members is explained as below.
Here are the steps for the design procedure for one way slab in steps. In case of one ways slabs, the aci approximate analysis is applicable to one way slab system where a one way slab is continuous with a one way slab. Each cad and any associated text, image or data is in no way sponsored by or affiliated with any company, organization or realworld item, product, or good it may purport to portray. The floor is to be designed to carry a service live load and a dead load on the slab due to selfweight plus weight of. Two way joist slab often called two way ribbed slab or waffle slab is an economical floor system when the spans are long andor loads are high. Two way concrete slabs with openings the static system and the design of reinforcement.
The program covers wide range of two way slab systems and can be used for more complex slab layouts. Structural consideration in design of reinforced concrete slabs with openings asaph kamau tayebwa1 and michael kyakula2. Pt designer is a computer program for the design and analysis of linear posttensioned concrete floor systems. Slab is one of the most famous part of a construction project. The first reinforced concrete design manual formerly titled aci design handbook was developed in accordance with the design provisions of 1963 aci 318 building code by aci committee 340, design aids for building codes, whose mission was to develop handbook editions in accordance with the aci 318 building code. Design of slab examples and tutorials by sharifah maszura syed mohsin example 1. Slabs can be designed by direct design method known as ddm and another method for design is coefficient method which is the easier one. Two way slab is a slab supported by beams on all the four sides and the loads are carried by the supports along both directions, it is known as two way slab. Distribute moments transverse at critical sections to column and middlestrip and if. This is relatively high when compared to other materials, for example the. Step 2 design forces draw panel of slab and indicate maximum design moments, shears and in plane loads, if any, per unit width of slab. Flat slab analysis, design and detailing pdf civil engineering. Twoway concrete slab with beams spanning between supports.
The other ways of analysis of twoway slabs are the direct design method and the equivalent frame method. Concrete slabs are commonly divided into the following types. The pca computer program pcaslab can be used to expedite the design of different slab systems. The oneway slab is deflected in one way direction and primary reinforcement is placed in one direction whereas the twoway slab deflect in two directions and primary reinforcement placement is in two directions. Redistribution of 10% may be allowed when method 3 or method 4 is adopted.
Strength design or ultimatestrength design usd strength design or ultimatestrength design usd with strength design method, the working dead load dl and live load ll are. In flatplate floors, slab column connections are subjected to high shear stresses produced by the transfer of axial loads and bending moments between slab and columns. Rectangular beams and one way slabs page 2 of 9 two methods. Design examples look at example 7 design of a flat plate floor without spandrel beams direct design method look at example 9 design of a two way slab with beams in both directions. Oneway and twoway slabs oneway slabs transfer the imposed.
There are several methods by which two way slabs can be designed. Reinforced concrete design 1 design of slab examples. Bending will take place in the two directions in a dishlike form. Twoway concrete floor slab with beams design and detailing. This paper focuses on analysis of two way ribbed and waffle slabs with hidden beams. Reinforced concrete design in accordance with as3600 ccaa. Jul 22, 2015 design of two way ribbed slab 18 x 25 m clear span 1. In this video deisgn of two way slabs has been covered using is 456.
The proposed slab system must be able to be constructed at a reasonable cost. In a two way slab the slab has to resist the following forces. That is, the load factor at which the uls moment equals the moment capacity. Here the slab or slab panel is supported along its four edges by relatively deep, stiff, monolithic concrete beams or walls or steel girders.
Allowable stress design or working stress design wsd 2. Analysis and design of slabs two way two way edge supported slabs two way slabs. In case of one way slab we all know that,when loaded such slabs bend into cylindrical surface. Aci 31811 code provides two methods for two way slab design one of which is direct design method. The first reinforced concrete design manual formerly titled aci design handbook was developed in. Two way columnsupported slabs two way columnsupported slabs. Member design reinforced concrete two way spanning.
If items found in this document are desired by the architectengineer to be a part of the contract documents, they shall be restated in mandatory language for incorporation by the architectengineer. The output of the program for the slab in the example is shown in the following pages. Two way slabs have two way bending unlike one way slab. The document is intended primarily for design engineers, but we shall be very pleased if it is also of use. Design of a structural member is governed by what kind of forces it has to resist. When a rectangular slab is supported on all the sides and the lengthtobreadth ratio is less than two, it is considered to be a two way slab. Best practices of concrete pavement transition design and. Concrete 3 design of concrete beam and slab twoway slab. Chapter 3 design of rectangular beams and oneway slabs. Basic steps in two way slab design choose layout and type of slab. The design bending moment of two way restrained slab can be calculated as follows.
The slab thickness for the owcs was determined to be 5 and was 10 for the twcs. Tayabji regional manager ctl group report 053201 project 05320. Therefore, primary reinforcement is presented in both directions for resisting the loads. One way and two way slabs one way slabs transfer the imposed loads in one direction only. 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 distribution of floor loads on floor beams is based on the geometric configuration of the beams forming the grid. Flat slab analysis, design and detailing pdf flat slab system is an important division of concrete floor system. Analysis and design of slabs one way civil engineers pk. Flat plate concrete floor system does not use beams between columns or. Design the 4 marked slab panels of an ordinary house. Sci p300, composite slabs and beams using steel decking. Design of slabtwo way excel sheet online civilforum. Analysis and design of slabs two way civil engineers pk. The codes governing the design of the one way slab will be aci 31802 and ibc 2003.
The following example illustrates the design methods presented in the pca book. Zollinger program manager, rigid pavements texas transportation institute and shiraz d. Beamless slabs beamless slabs are supported only on columns and are applied mostly in large industrial and public. Two way restrained slab if the slabs consist more than one panel or corner of the slab are prevent against lifting it is define as two way restrained slab. Please read the lauses mentioned in the video while solving the problem. Ce 433, fall 2006 slab design example 1 6 design a oneway slab for an exterior bay of a multistory office building using the information specified below. Twoway slab analysis and design using equivalent frame method efm. Structural consideration in design of reinforced concrete. Multi storey, post tension, two way, design, comparison. One way and twoway slabs one way slabs transfer the imposed loads in one direction only. Assume partitions cannot be damaged by deflections. Twoway slab design based on aci 31811 using finite element method.
Accordingly, main reinforcement is required in the two directions. In two way slab, load is delivered in both the directions. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan. Simply supported one way slab a rectangular reinforced concrete slab is simplysupported on two masonry walls 250 mm thick and 3.
Generally, there are two types of slab which are one way and two way slabs. The basic design procedure of a twoway slab system has five steps. Reinforced concrete design 1 design of slab examples and. For those who do not know what are the des ign requirements of a slab. Static equilibrium of two way slabs total moment in both beams full load was transferred eastwest by the planks and then was transferred northsouth by the beams. A slab is a concrete structure constructed to provide a flat surface. When the ratio of long span to short span is less than 2, then the slab is known as a slab spanning in two directions or two way slab. Aug 03, 2016 the design steps have been presented in the following question how do i degisn two way slab. Tributary areas many floor systems consist of a reinforced concrete slab supported on a rectangular grid of beams. Pdf slabs are the flooring systems of most structures including office. Pt designer design of posttensioned concrete floors. Two way slab design spreadsheet 6ngejq6yg2lv idocpub. Flat slab analysis and design pdf flat slab design pdf 1.
Twoway joist waffle slab design approach and methodology. Ultimate behavior of one way spanning slab linear elastic analysis methods such as moment distribution are linear elastic methods. Design criteria there are three criteria which must be considered for the design of a conventional one way slab system. From the study it is considered that post tension slab is more economical than two way slab.
Waffle slab analysis and design is similar to the procedure used with flat plates except that special considerations need to be taken into account to reduce the complexity of calculations needed when. These materials are originally located at different websites. Dissatisfaction with results of previously required procedures of analysis and design for two way slab beam systems was the original reason for the massive research upon two way slab systems begun about 1955. It is recommended to create the design of slab with the use of excel sheet as the process will be very simple and lots of time will be saved. Plan view of floor system assume partitions will not be damaged by deflections. The building is located in seismic zone iii on a site with medium soil. To see their result for this slab we will find the load factor. Design procedure steps for one way slab slab design steps. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. There are many methods that are used to analyze two way slabs and the precision of these methods vary depending.
All methods are viable provided that the safety and serviceability of the elements are within the acceptable limits. Twoway concrete slab on beams floor analysis and design. I have developed a microssoft excel software for design of a two way rcc slab. A concrete slab is a common structural element of modern buildings, consisting of a flat. Twoway slabs supported on beams the critical location is found at d distance from the column, where the supporting beams are stiff and are capable of transmitting floor loads to the columns. The following example illustrates the example building. The general layout of the building is shown in figure 1. Slab resting on walls or sufficiently deep and rigid beams on all sides. Twoway joist slab often called twoway ribbed slab or waffle slab is an economical floor system when the spans are long andor loads are high. A six storey building for a commercial complex has plan dimensions as shown in figure 1. Two way slab design by direct design method as per aci 31811, step by step procedure and limitations of direct design method for two way slab is presented. Design of slab examples and tutorials by sharifah maszura syed mohsin example 2. One way spanning slabs should be treated as beams of unit width and chapter 2 should be followed except for minimum shear reinforcement. But in case of two way slab when loaded such slabs bend into a dished surface rather than a cylindrical surface.
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