A rectangular reinforced concrete slab is simply supported on two masonry walls 250 mm thick and. Corners of the twoway slab lift up if the slab is not cast monolithically with the supports wallsbeams. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan. How to design a twoway slab free download as powerpoint presentation. Design of twoway slab by coefficient method the constructor.
The design shear force of twoway restrained slab can be calculated as follows. Useful illustration example is presented in this study according to the. A discreteelement method of multipleloading analysis for twoway bridge floor slabs by john j. Design of a two way rcc slab structural engineering. Two way slabs have two way bending unlike one way slab. Design of a two way slabs for punching shear resistance. Aci in 1963 to design twoway slabs carried by steel beams, deep beam, or walls. Design of two way slabs is 456 limit state method youtube. All methods are viable provided that the safety and serviceability of the elements are within the acceptable limits. Distribute moments transverse at critical sections to column and middlestrip and if. Bending will take place in the two directions in a dishlike form. In this video deisgn of two way slabs has been covered using is 456.
The twoway waffle slab is provided with a bigger span as compared to the solid slab. Two way slab design 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. The unit weight of reinforced concrete is assumed to be 24 knm3. Chapter 3 design of rectangular beams and oneway slabs. There are several methods by which twoway slabs can be designed. Two way reinforced concrete slab design spreadsheet working. Tn342 design example 2way mondada 093090 adapt corporation. For designing two way slab refer is code 4562000 and sp16. The twoway waffle slab is economical when it is used in the modular or prefabricated form. Collection of civil engineering design spreadsheet. Direct design method ddm twoway slabs satisfying the limits in aci 31814 8. Concrete mix design calculation for m20, m25, m30 concrete with. Time saving design aids twoway slabs page 1 of 14 the following example illustrates the design methods presented in the article timesaving design aids for reinforced concrete, part 2.
Difference between one way slab and two way slab simple. Reinforced concrete design 1 design of slab examples. The execution of the design will be explained with reference to an example. Existing twoway slab design procedures the example structure.
Two way slab design to aci free download and software. Founded in 1904 and headquartered in farmington hills, michigan, usa, the american concrete institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensusbased standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design. Efm is the most comprehensive and detailed procedure provided by the aci 318 for the analysis and design of twoway slab systems where the structure is modeled by a series of equivalent frames interior and exterior on. Rectangular beams and oneway slabs page 2 of 9 two methods. This can be used in conjunction with a structural analysis program such as our slab analysis tool. For economical design of similar structures a smaller slab thickness leading to values between 60% to 80% of balanced selfweight is generally selected. The one way slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. This spreadsheet is an extremely efficient tool and allows to quickly design two way slabs to aci code. Twoway 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. This example goes through the design of a simplysupported oneway slab on beams. Notes author staff bridgesight software sponsor bridgesight software. Two way slab design spreadsheet the engineering community.
Two way slab design based on aci 31811 using finite element method. The coefficient method may be the simplest, easiest and the quickest approach for the design of twoway slab supported by edge beam on all slab sides. Therefore, the slab can be reinforced with shear reinforcement complying with detailing rules defined in subclause 7. Slabs are generally designed on the assumption that they consists of a number of beams of breadth one meter. 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. What is the formula for taking load from two way slab for.
How can you design a 2 way spanning slab and be able to know the reinforcement size to be used in your slab as well as the spacing needed when tieing your reinforcements. Design of reinforced concrete structures ii twoway slabs 1 1. Hello, today i am introducing to you an excel spreadsheet program specially created to help design one way continuous reinforced concrete slabs. The same is true for a two way slab or any other floor system where. The construction and design of concrete slabs on grade 2012 instructor. 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. Design of a two way rcc slab structural engineering forum.
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. The same is true for a twoway slab or any other floor system where. Example calculations for this and all other example problems the following data from the canam united steel deck design manual and catalog of steel deck products will be used and are worked using lrfd methodology. It shows possible solutions of twoway prestressed floors depending on different factors. This spreadsheet allows user to design a two way spanning reinforced concrete slab in accordance with the british standard bs 8110. The two classifications are oneway slab and twoway slab. I have developed a microssoft excel software for design of a two way rcc slab. 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. Two way slab design by direct design method as per aci 31811. Beams of width and depth are provided on all column lines. Design procedure steps for one way slab slab design steps. Analysis and design of slabs two way civil engineers pk. Download our free two way slab design spreadsheet only from samotech.
Determine moments at critical sections in each direction, normally the negative. Allowable stress design or working stress design wsd 2. Pdf design of reinforced concrete circular slabs by twoway. Calculate quantities of materials for concrete design of retaining wall excel sheet construction quantities of materials estimate earthwork calculation. Reinforced concrete slab design using the empirical method. Title reinforced concrete slab design using the empirical method publication no. Design of two way slab example pdf flat slab design pdf bs 8110 concrete design for slab how to pour a concrete slab how to calculate formwork for slab slab on grade foundation post tension slab concrete beam and slab bridge how to pour a 26x36 concrwte concrete slab operation management 9th edition myomlb nigel slab usercentered design, activitycentered design, and goaldirected design.
Shear force at short span, shear force at long span, where. Twoway slab analysis and design using equivalent frame method efm. There are important differences between designbuild and the more traditional method of designbidbuild. The basic design procedure of a twoway slab system has five steps. Steps in the design of a 2way spanning slab with bs8110 lets talk about slab design. However, a slab with length breadth ratio of not less than 1. Accordingly, main reinforcement is required in the two directions. Slab is one of the most famous part of a construction project. Simplified design to bs 5400 bridge design to the eurocodes in part d.
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. In two way slab, the ratio of longer span l to shorter span b is less than 2. Bss090119991 abstract this design example illustrates the empirical design method for composite concrete bridge decks specified in article 9. This paper focuses on analysis of two way ribbed and waffle slabs with hidden beams. Two way rcc slab designing excel sheet civil engineering. Brick masonry building materials building tips formworkshuttering. Twoway slab action is assumed in a ribbed floor made of the doubletee section precast, in the ribbed floor with integral beams.
Fanella, which appeared in the october 2001 edition of structural engineer magazine. Slabs are primarily categorized as either one way or two ways. Here ratio of longer span of slab to the shorter span of slab is greater than 2. Design of two way ribbed slab 18 x 25 m clear span 1. Design of slabtwo way excel sheet online civilforum.
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. Department of transportation federal high way administration bridge deck design. Posttensioning with or without bonding of tendons 3 1. This data is good for know the difference between one way slab and two way slab but if u provide to how to reinforcement design in one way and two way slab so its very helpfull. They may be supported on two opposite sides only fig. Foreword this spreadsheet performs an analysis and design of twoway spanning reinforced concrete slab. The construction and design of concrete slabs on grade. Example design of two way edgesupported solid slab. The following example illustrates the example building. A one way slab is a slab in which its length divided by its breadth is greater than or equal to 2. Rectangular beams and one way slabs page 2 of 9 two methods. The following example illustrates the design methods presented in the pca book simplified design reinforced concrete buildings of moderate size and height third edition.
If the proportion of longer dimension of the slab panel to the shorter dimension is more than or equivalent to 2 then it is defined as one way slab. The ratio lb which is less than 2 is known as two way slab. If, it is below 2 then it is described as two way slab. A single slab with oneway reinforcement rebars will be analyzed with rcsolver. Analysis of two way ribbed and waffle slabs with hidden beams. Foreword the reinforced concrete design manual sp1711 is intended to provide guidance and assistance to professionals engaged in the design of castinplace reinforced concrete structures. Getting the details right in the contracts can make the difference between success or failure. The oneway slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. But rectangular slabs often have such proportions and supports e. A monolithic reinforced concrete floor is to be composed of rectangular bays measuring, as shown.
Effective depth d span ldbasic x modification factor for obtaining modification factor, the percentage of steel for slab can be assumed from 0. Jul 10, 2017 this example goes through the design of a simplysupported oneway slab on beams. Flat plate concrete floor system does not use beams between columns or. Oneway and twoway slabs university of asia pacific. In twoway slabs shorter direction strip carry greater %age of load. A copy of the tables is provided in the appendix and also. Chapter 3 design of rectangular beams and oneway slabs 12. Design of reinforced concrete structures ii twoway slabs. The k value used for floor slab design reflects the response of the subgrade under temporary elastic conditions and small deflections, usually 0. Twoway slab design static equilibrium of twoway slabs total moment in both beams full load was transferred eastwest by the planks and then was transferred northsouth by the beams. Example the floor system consists of solid slabs and beams in two directions. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. In two way slabs shorter direction strip carry greater %age of load.
Closed form equations have been driven by author for the purposes of analysis. The slab is supported on beams of size 225 x 500 mm spaced at 4. Chajjas and verandahs are an practical example of one way slab. Aci318 code provides two design procedures for slab systems. Serviceability limit state 11 41 crack limitation 11 42. There are many methods that are used to analyze two way slabs and the precision of these methods vary depending. Download two way slab design excel sheet template for free. Twoway slabs have two way bending unlike oneway slab. Two way rcc slab designing tool in microsoft excel developed by shankar tayal a 3rd year student of school of infrastructure, indian institute of technology, bhubaneswar this is a part of his project economic design of two way rcc slabs under prof s.
Several residential and office buildings which contain rooms have two way slab. The twoway slab is designed for both the directions as it bends in both directions. The design shear force v d is below the maximum punching strength v rd,max. One way and two way slabs one way slabs transfer the imposed loads in one direction only. His analysis suggested that the current slab design. Firstly, one has to check if the design shear force v d is smaller than the maximum punching strength v rd,max. Slabs and flat slabs lecture 5 19 th october 2016 contents lecture 5 designing for shear in slabs including punching shear detailing solid slabs flat slab design includes flexure worked example exercise punching shear. For those who do not know what are the des ign requirements of a slab. Hi bro, do you have design example of rectangular manhole. 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. The twoway slab will deflect in a dish or saucerlike form under the action of loads. Assume partitions cannot be damaged by deflections. One way slab is supported by two parallel beams or walls.
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. Jul 22, 2015 design of two way ribbed slab 18 x 25 m clear span 1. Pdf the article is about design of prestressed slabs. Design of slab examples and tutorials by sharifah maszura syed mohsin example 2. Continuous one way slab figure 1 shows a clear area of 12 m x 8. Two way reinforced concrete slab design spreadsheet working stress design coefficient method. Generally, there are two types of slab which are one way and two way slabs. Oneway and twoway slabs oneway slabs transfer the imposed loads in one direction only. Twoway slab design based on aci 31811 using finite element method. The specified design strength of the concrete, is 25 mpa and the specified yield strength of the reinforcement, fy, is 400 mpa. Oneway and twoway slabs oneway slabs transfer the imposed. Figure 2 top view of continuous rc circular twoway ribbed slab.
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