Two-way slab design pdf

The dimensions of an interior bay are shown in figure 1. Here the ratio of longer span of slab to the shorter span of slab is less or equals to 2. However main reinforcement bar and distribution bar. How to design a two way slab free download as powerpoint presentation. Contains all design checks required by the american concrete institute code and all the conditions that must be met during the design process. Nov 30, 2018 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. Design of reinforced concrete structures ii twoway slabs 1 1. Reinforced concrete design 1 design of slab examples and. The following example illustrates the design methods presented in the pca book simplified design reinforced concrete buildings of moderate size and height third edition. Design of twoway floor slab system comparison of oneway and. Chapter 3 design of rectangular beams and oneway slabs. 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. The same is true for a two way slab or any other floor system.

Design the slab, following the provisions of the ack code. Flat slab system is an important division of concrete floor system. Bending will take place in the two directions in a dishlike form. How to design a twoway slab free download as powerpoint presentation. A combination of these values will determine the slab stresses at the time of stressing and at service loads. Chapter 3 design of rectangular beams and oneway slabs 12 h a 12 strip in a simply supported one way sl ab h. Twoway concrete slab with beams spanning between supports. 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. In two way slabs, load will be carried in both the directions. Design of two way slab example pdf flat slab design pdf bs 8110 concrete design for slab beam and slab bridge how to calculate formwork for slab slab on grade foundation how to pour a concrete slab beam and slab bridge uk 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, activity. The same is true for a two way slab or any other floor system where.

Oneway and twoway slabs oneway slabs transfer the imposed. Accordingly, main reinforcement is required in the two directions. Interior bay dimensions 20 24 this example is to be used for educational purposes only. Load transfer in a one way slab, b two way slab nilson fig. 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. Reinforced concrete design 1 design of slab examples. Twoway slabs structural engineering forum of india, sefi. Basic steps in two way slab design choose layout and type of slab. Aug 23, 2017 two way slab is a slab in which the ratio of longer side to the shorter side is less than or equal to two. The design bending moment of twoway restrained slab can be calculated as follows. The two classifications are oneway slab and twoway slab. Slab is one of the most famous part of a construction project.

A rectangular reinforced concrete slab is simply supported on two masonry walls 250 mm thick and. There are two types of slab classification based on the direction of bending occurs in these slabs. For uniformly distributed loads of w per square foot of the slab, each strip acts approximately like a simple beam uniformly loaded by its share of w. Design of a two way rcc slab structural engineering.

The same is true for a twoway slab or any other floor system where. Member design reinforced concrete two way spanning. Design the slab system shown in figure 1 for an intermediate floor where the. May 02, 2017 chajjas and verandahs are an practical example of one way slab. A civil engineer must know all the aspects regarding the flat floor system. However main reinforcement bar and distribution bar in transverse direction.

The following example illustrates the design methods presented in the pca book simplified designreinforced concrete buildings of moderate size and height third edition. Chapter 3 design of rectangular beams and oneway slabs 12. Download two way slab design excel sheet template for free. I have developed a microssoft excel software for design of a two way rcc slab. Slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs, bridges, and other types of structures. Design of rectangular beams and oneway slabs continued. The slab may be supported by walls, by reinforced concrete beams usually cast monolithically with the slab, by s. They may be supported on two opposite sides only fig. Twoway slab action is assumed in a ribbed floor made of the doubletee section. Distribute moments transverse at critical sections to column and middlestrip and if.

Twoway slabs have two way bending unlike oneway slab. Flat slab analysis, design and detailing pdf civil. The same is true for a twoway slab or any other floor system. The parameter used to define the relative stiffness of the beam and slab spanning in. This spreadsheet performs an analysis and design of twoway spanning reinforced concrete slab. Two way slabs have two way bending unlike one way slab. The twoway waffle slab is economical when it is used in the modular or prefabricated form. Flat slab analysis, design and detailing pdf civil engineering. Use the aci 318 direct design method to design an interior bay of a flat plate slab system of multi bay building. Find the following parameters for design moments in step 2 per unit width step 4 note. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. Determine moments at critical sections in each direction, normally the negative moments at.

Two way slab being supported on four sides the load will be carried in both the directions. Two way slab design spreadsheets to eurocode 2 14 march 2018 off by the engineering community twoway spanning slabs for rectangular slabs with standard edge conditions and subject to uniformly distributed loads, normally the bending moments are obtained using tabulated coefficients. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types. Two way slab design by direct design method as per aci 318 11, step by step procedure and limitations of direct design method for two way. 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. The lateral loads are independently resisted by shear walls. Pdf historical perspective on the evolution of twoway slab design. Mention the parameters governing slab moment coefficients and explain their effects on moment. In this video deisgn of two way slabs has been covered using is 456. The program covers wide range of two way slab systems and can be used for more complex slab layouts. Two way slab design by direct design method as per aci 31811.

Unless otherwise noted, all referenced table, figure, and equation. 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. Member design reinforced concrete two way spanning slab bs8110 v2015. The slab has to carry a distributed permanent action of 1. Oneway and twoway slabs oneway slabs transfer the imposed loads in one direction only. The output of the program for the slab in the example is shown in the following pages. Design of two way slab example pdf flat slab design pdf bs 8110 concrete design for slab beam and slab bridge how to calculate formwork for slab slab on grade foundation how to pour a concrete slab beam and slab bridge uk 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. Design procedure steps for one way slab slab design steps. A reinforced concrete slab is a broad, flat plate, usually horizontal, with top and bottom surfaces parallel or nearly so. This condition occur when the slabs are connected monolithically with support.

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. In this article, i will discuss how to design one way slab with example. Twoway concrete slab on beams floor analysis and design. Design of two way slabs is 456 limit state method youtube. Type of slab is strongly affected by architectural and construction considerations. Two way slab a bending of center strip, b grid model figure. Basic steps in twoway slab design choose layout and type of slab.

Sep 03, 2011 reinforced concrete sk 33 section through slab showing stress due to moment. The following example illustrates the example building. Introduction in reinforced concrete construction, slabs are used to provide flat, useful surfaces. Slabs are usually used in floor and roof construction. Here, we have tried to gather various reading materials available in the web about flat slab floor system in one place. Simply supported one way slab a rectangular reinforced concrete slab is simplysupported on two masonry walls 250 mm thick and 3. Member design reinforced concrete two way spanning slab. Slab shear strength twoway shear check the adequacy of slab thickness for punching shear twoway shear at an interior column figure 4.

In twoway slabs shorter direction strip carry greater %age of load. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan. 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 a two way slabs for punching shear resistance. Two way slab design spreadsheet the engineering community. Equivalent frame method use elastic frame analysis to compute. A reinforced concrete slab is built integrally with its supports and consists of two equal spans, each with a clear span of 15 ft. 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. One way and two way slab reinforcement in detail at. When a rectangular slab is supported on all the sides and the lengthtobreadth ratio is less than two, it is considered to be. Analysis and design of twoway slabs page 1 chapter 3. These materials are originally located at different websites. 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. Mar 14, 2018 two way slab design spreadsheets to eurocode 2 14 march 2018 off by the engineering community two way spanning slabs for rectangular slabs with standard edge conditions and subject to uniformly distributed loads, normally the bending moments are obtained using tabulated coefficients.

Two way slab is a slab in which the ratio of longer side to the shorter side is less than or equal to two. Analysis of two way ribbed and waffle slabs with hidden beams. Twoway slab design static equilibrium of twoway slabs analogy of twoway slab to plank and beam floor section aa. The pca computer program pcaslab can be used to expedite the design of different slab systems. Scribd is the worlds largest social reading and publishing site. The basic design procedure of a twoway slab system has five steps. Design of reinforced concrete structures ii two way slabs 1 1.

The other ways of analysis of twoway slabs are the direct design method and the equivalent frame method. In two way slabs shorter direction strip carry greater %age of load. Two way slab design panel select boundary condition of slab for upliftment of corners. Twoway concrete floor slab with beams design and detailing. Load transfer in a oneway slab, b twoway slab nilson fig. Design of slab for flexure 067 m unit width of slab. Pdf reinforced concrete twoway slabs have evolved in the past century from simple solid slabs supported on beams on all sides to a.

Reinforced concrete sk 33 section through slab showing stress due to moment. Design of reinforced concrete structures ii twoway slabs. When a slab is supported on all four sides and the ratio of long span to short span is equal or greater than two, it will be considered as one way slab. Moment variations of a uniformly loaded slab with simple supports on four sides. The basic design procedure of a two way slab system has five steps. This method was provided in the american concrete institute aci in 1963 to design twoway slabs carried by steel beams, deep beam, or walls. Slab being the first element to be designed has pretty much importance as the whole structural design is based on the design of slab. For those who do not know what are the des ign requirements of a slab. Generally, there are two types of slab which are one way and two way slabs. Design of two way slabs by coefficient method slab is one of the basic parts of a building. Jul 02, 2010 lecture series on design of reinforced concrete structures by prof. An optimal plan geometry with all same supports is a square, based on load distribution into both directions. The oneway slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. Preliminary design of slab thickness thickness design depends on boundary conditions supports.

Twoway joist concrete slab floor waffle slab system. 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 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. It can be used by both practicing engineers and students. Please read the lauses mentioned in the video while solving the problem. Analysis and design of slabs two way civil engineers pk. 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. 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. In two way slab, the ratio of longer span l to shorter span b is less than 2.

Here are the steps for the design procedure for one way slab in steps. 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. 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. This is because its length to width ratio is longshort not big enough for loads to travel in the short direction onl. Apr 18, 2019 this spreadsheet performs an analysis and design of two way spanning reinforced concrete slab. The program covers wide range of twoway slab systems and can be used for more complex slab layouts. A twoway slab tws is simply a slab carrying loads in both directions length and width to its supports beams or columns. The load on the slab is carried by the short span in one direction. Dhang, department of civil engineering, iit kharagpur. Design of slab examples and tutorials by sharifah maszura syed mohsin example 1. Simply supported slab upliftment of corners continuous slab no upliftment. One way slab design how to design one way slab daily civil. Two way concretefloor slab withbeams design detailing. Twoway slab design panel select boundary condition of slab for upliftment of corners.