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. In two way slab, the ratio of longer span l to shorter span b is less than 2. Design of a two way rcc slab structural engineering forum. Design of two way slabs is 456 limit state method youtube. Pdf design calculation design of one way slab slab s1. This example is to be used for educational purposes only. Flat plate concrete floor system does not use beams between columns or. Posttensioned concrete design spreadsheet program a pdh. I would really appreciate it if somebody would post a link or a document that showcases an example of a complete waffle slab two way joist slab design. Redistribution of 10% may be allowed when method 3 or method 4 is adopted.
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. The service live load is 100 psf and 4000 psi concrete is specified for use with steel with a yield stress equal to 60000 psi. The high accuracy in design calculations of structures is undesirable because. I have found several links online but they almost all explain how to figure out the dimensions with little mention of the reinforcement. It is generally horizontal and contains lesser thickness with regards to. The program is divided into three separate screens, which correspond to the three major areas of concern in the design of a posttensioned member.
Twoway slabs structural engineering forum of india, sefi. A 2 2area 2 a c 2 2 posttensioned concrete design table 11 list of symbols used in the aci 31808 code cp area enclosed by the outside perimeter of the section, in a g gross area of concrete, in a 2 l total area of longitudinal reinforcement to resist torsion, in a o area enclosed by the shear flow path, sqin a oh area enclosed by the centerline of the outermost closed. This paper focuses on analysis of two way ribbed and waffle slabs with hidden beams. Ddm can be found in the twoway plate concrete floor system design example. 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. Waffle slab design example structural engineering general. Twoway flat plate concrete floor system analysis and design.
Design of reinforced concrete structures ii twoway slabs. The same is true for a two way slab or any other floor system. The steel fixers formwork drawing of a twoway slab for reasons regarding behaviour, safety and economical design, the twoway slab is far more efficient than the equivalent one way slab. Jul 22, 2015 design of two way ribbed slab 18 x 25 m clear span 1. Generally, there are two types of slab which are one way and two way slabs. Therefore, primary reinforcement is presented in both directions for resisting the loads. The dimensions of an interior bay are shown in figure 1. Reinforcement detailing of reinforced concrete slabs. The program is developed around the robust computational core of two popular programs ptdata. Example design of two way edgesupported solid slab. The 2012 edition of the reinforced concrete design manual sp1711 was developed in accordance with the design provisions of aci 31811, and is consistent with the format of sp1709.
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. The pca computer program pcaslab can be used to expedite the design of different slab systems. Flexural design of two way slabs following the direct design method and the equivalent frame method is shown, and the seminar concludes with a design example of a. Two way post tension slab design khmer language civil. In this video deisgn of two way slabs has been covered using is 456. The reinforced concrete design handbook now provides dozens of design examples of various reinforced concrete members, such as one and two way slabs, beams, columns, walls, diaphragms, footings, and retaining walls.
In 1965 the writer developed a complete, overall design system, later modified to conform, in format. Pdf analysis of two way ribbed and waffle slabs with. There are many methods that are used to analyze two way slabs and the precision of these methods vary depending. Accordingly, main reinforcement is required in the two directions. 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. A six storey building for a commercial complex has plan dimensions as shown in figure 1. This program is more effective for analysis the two way slab. Plan view of floor system assume partitions will not be damaged by deflections. 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. Ec2 webinar autumn 2016 lecture 52 designing for shear in slabs when shear reinforcement is not required e.
This spreadsheet is an extremely efficient tool and allows to quickly design two way slabs to aci code. 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. Pt designer is a computer program for the design and analysis of linear posttensioned concrete floor systems. Also the slab is supported four sides but the length breadth lylxration is greater than or equal to two, the slab is designed as one way slab. 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. 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.
Jul 02, 2018 difference between one way slab and two way slab learning technology official website. Reinforcement implementation, static and dynamic analysis for reasons regarding behaviour, safety and economical design, the two way slab is far more efficient than the equivalent one way slab. Designing of slabs depends upon whether it is a oneway or a two way slab, the end conditions and the loading. A reinforced concrete slab is built integrally with its supports and consists of two equal spans, each with a clear span of 15 ft. The same is true for a twoway slab or any other floor system where. To connect with me personally subscribe hinditalkwithmukesh. Detailing and design of earthquake resistant buildings made of reinforced concrete. 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 or panel is said to be two way slab if the ratio of longer span to the shorter span is not greater than 2 two. The other ways of analysis of twoway slabs are the direct design method and the equivalent frame method. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan. 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.
Basic steps in two way slab design choose layout and type of slab. One way and two way slabs one way slabs transfer the imposed loads in one direction only. The institution of structural engineers the institution of civil engineers march 2000 manual for the design of reinforced concrete building structures to ec2. This is a part of his project economic design of two way rcc slabs under prof s. The design bending moment of two way restrained slab can be calculated as follows. Design the slab following the provisions of the aci code. Chapter 3 design of rectangular beams and oneway slabs 12. Two types of shear failure mechanism in 2 way slabs. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types. The slab panel is part of the suspended floor slab and so the upper and lower surfaces of the slab are interior for durability cover and crack control purposes. 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. The following example illustrates the design methods presented in the pca book. In this example deflection will be calculated and checked to satisfy project deflection limits.
Difference between one way slab and two way slab learning. A subsequent report established the feasibility of using posttensioning in slabonground construction and verified many of the brab assumptions. May 07, 2009 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. The program covers wide range of two way slab systems and can be used for more complex slab layouts. Slab is one of the most famous part of a construction project. Bending will take place in the two directions in a dishlike fo. Twoway restrained slab if the slabs consist more than one panel or corner of the slab are prevent against lifting it is define as twoway restrained slab. Pt designer design of posttensioned concrete floors. Minimum depth of 2 way slab for deflection control. Analysis and design of slabs two way two way edge supported slabs two way slabs. Fanella, which appeared in the october 2001 edition of structural engineer magazine. Bending will take place in the two directions in a dishlike form. The service live load is 100 psf, and 4000 psi concrete is specified for use with steel with a yield stress equal to 60,000 psi. Twoway flat plate concrete floor system design structurepoint.
Reinforced concrete design 1 design of slab examples. They may be supported on two opposite sides only fig. Each single slabs are referred to as panels, if the slab is continuous over supports. The building is located in seismic zone iii on a site with medium soil. 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. 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. How to design a two way slab free download as powerpoint presentation. In two way slab, load is delivered in both the directions. This spreadsheet program provides for the design and analysis of posttensioned concrete one way beam and slab systems and two way flat plate slab systems. A reinforced concrete slab is built integrally with its supports and consists of equal span of 15 ft. Two way slab design by direct design method as per aci 31811. 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.
Design of slab examples and tutorials by sharifah maszura syed mohsin. In this article, it is assumed that slab thickness is determine but calculation of column and middle strips is explained in the. Design of reinforced concrete structures ii two way slabs 1 1. Use the aci 318 direct design method to design an interior bay of a flat plate slab system of multi bay building.
Design calculation design of one way slab slab s1 span of one way slab l 2m section provided d mm d 105 mm loads on slab self weight of slab 3. Jun 14, 2017 download two way slab design excel sheet template. Two way slab design based on aci 31811 using finite element method. Oneway and twoway slabs oneway slabs transfer the imposed. The slab is to be designed as a reinforced concrete two way slab supported on beams. Slab resting on walls or sufficiently deep and rigid beams on all sides. Continuous one way slab figure 1 shows a clear area of 12 m x 8. Shear failure occurs when inclined cracks form due to flexural and shearing stresses.
A subsequent report established the feasibility of using posttensioning in slab onground construction and verified many of the brab assumptions. Twoway concrete slab with beams spanning between supports. Beam and slab arrangement can be the best example for one way and two way slabs. What are the difference between tender and contract documents. Two way slab design to aci free download and software.
Unless otherwise noted, all referenced table, figure, and equation. For consistency, many of the numerical examples are based on a fictitious sevenstory reinforced concrete building. How to design two way slab with coefficient method in excel sheet slab refers to a common structural component of modern building. Oneway slabs transfer the imposed loads in one direction only. Summary and comparison of twoway slab design results.
Two way slabs have two way bending unlike one way slab. The basic design procedure of a two way slab system has five steps. Twoway concrete floor slab with beams design and detailing version. The following example illustrates the design methods presented in the pca book simplified design reinforced concrete buildings of moderate size and height third edition. The reinforced design manual concrete in accordance with aci 31811. Distribute moments transverse at critical sections to column and middlestrip and if. Manual for the design of reinforced concrete building. A slab is supported only one direction that is one way slab now tha loads are transferred only this two supports. Slabs can be designed by direct design method known as ddm and another method for design is coefficient method which is the easier one. Jul 10, 2017 this example goes through the design of a simplysupported oneway slab on beams. 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. When a rectangular slab is supported on all the sides and the lengthtobreadth ratio is less than two, it is considered to be a twoway slab.
No redistribution is allowed when method 1 or method 2 of analysis in section 3. Two way rcc slab designing excel sheet civil engineering. Design of a two way slabs for punching shear resistance. Framing dead load selfweight superrimposed dead load 25 psf partitions, me, misc. Design of two way continuous slabs including detailing is 456 step by step duration. In two way slabs, load will be carried in both the directions. Design the slab, following the provisions of the ack code.
The design bending moment of twoway restrained slab can be calculated as follows. Analysis and design of slabs two way civil engineers pk. One way slab design procedure with example design of one. Buildinghow team integrates all earthquake resistant building technologies. Tn342 design example 2way mondada 093090 adapt corporation. Reinforced concrete design 1 design of slab examples and. The example presented here is for twoway posttensioned design. Design of slabtwo way excel sheet online civilforum. Design the 4 marked slab panels of an ordinary house. Designing for shear in slabs including punching shear detailing solid slabs flat slab design includes flexure worked example exercise punching shear. Beams of width and depth are provided on all column lines. Slabs are usually used in floor and roof construction.
This method was provided in the american concrete institute aci in 1963 to design two way slabs carried by steel beams, deep beam, or walls. Assume partitions cannot be damaged by deflections. 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 output of the program for the slab in the example is shown in the following pages. Oneway and twoway slabs university of asia pacific. This earlier handbook format was a collection of design aids and illustrative examples, generated in the precalculator era. Please read the lauses mentioned in the video while solving the problem. Contains all design checks required by the american concrete institute code and all the conditions that must be met during the design process.
The following example illustrates the design methods presented in aci 31805 and ibc 2003. 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. Unless otherwise noted, all referenced table, figure, and equation numbers are from these books. This condition occur when the slabs are connected monolithically with support. Download two way slab design excel sheet template for free. 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. Rectangular beams and one way slabs page 2 of 9 two methods.
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. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. 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. I have developed a microssoft excel software for design of a two way rcc slab. Allowable stress design or working stress design wsd 2. What is the formula for taking load from two way slab for. The slab is supported on beams of size 225 x 500 mm spaced at 4. Aci 31811 code provides two methods for two way slab design one of which is direct design method. A monolithic reinforced concrete floor is to be composed of rectangular bays measuring, as shown. The following example illustrates the example building. Pdf slabs are the flooring systems of most structures including office, commercial.
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