Determine moments at critical sections in each direction, normally the negative. Design procedure steps for one way slab slab design steps. Reinforced concrete design to bs8110 structural design 1. Difference between one way slab and two way slab what is. In two way slabs shorter direction strip carry greater %age of load. Next, select the structural system as one way slab.
In this post, we are going to explain how to calculate steel quantity for the slab. Nominal distribution reinforcement is provided in cross direction. Plan view of floor system assume partitions will not be damaged by deflections. This will appear at the top of the first page of the output. Twoway joist waffle slab design approach and methodology.
Feb 24, 2019 continuous oneway solid slab last updated on sun, 24 feb 2019 concrete structures this calculation is intended to show in detail the provisions of designing a slab to eurocode 2 using essentially the same slab as used in example 3. Reinforced concrete design to bs8110 structural design 1 lesson 5 5 4. Deep ribs, the concrete and steel quantities are relative low expensive formwork expected. If you continue browsing the site, you agree to the use of cookies on this website. The most straightforward routine structural element for illustration of design provisions from the code is that the one way slab.
If the ratio of longer span to shorter span is more than two, the slab is considered as one way slab and the same is designed considering that only shorter span contributes the load and bending moments. They may be supported on two opposite sides only fig. 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. Oneway and twoway slabs university of asia pacific. One way slab is a slab which is supported by beams on the two opposite sides to carry the load along one direction. Fundamentals of posttensioned concrete design for buildings part one a suncam online continuing. Chapter 3 design of rectangular beams and oneway slabs. D mm d 105 mm loads on slab self weight of slab 3.
Example design of two way edgesupported solid slab. Rectangular beams and one way slabs page 5 of 9 maximum permissible steel ratio, max an overreinforced beam will fail in a brittle manner while an underreinforced beam will. Slab design reading assignment chapter 9 of text and, chapter of aci31802. If slab is supported on all four sides and r shorter side longer side one way slab. Or if someone hasknows of a one way slab design example pdf or url metric units, and hopefully one that follows the canadian code it would be great. Oneway and two way slabs one way slabs transfer the imposed loads in one direction only. Bending will take place in the two directions in a dishlike form. Total load is carried in the direction perpendicular to the supporting beam. Determine suitable dimensions for the effective depth and width of the beam. Bending will take place in the two directions in a dishlike fo. 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 output of the program for the slab in the example is shown in the following pages.
Define the term slab, one way slab, two way slab, shrinkage and temperature reinforcement, main reinforcement. Can be used for larger spans with relatively higher cost and higher deflections one way joist system suitable span 6 to 9m with ll 46knm2. In the customanimation task pane, expand the contents by clicking the double arrow under the zoom entrance effect. If the length to breadth ratio of the room is less than 2, the slab is designed as a two way reinforced slab. This paper presents an experimental and computational study on ribbed slabs with widebeam, two one way slabs and two two way slabs, with variable. In case of one way slab, the main reinforcement of the slab, span along the width of the room while the distribution bars, laid at right angles to the main reinforcement, lie parallel to the length of the room.
A single slab with oneway reinforcement rebars will be analyzed with rcsolver. Nov 27, 20 one way slab design criteria with design example according to aci code slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. This will appear at the top of the each subsequent page of the output. One way slabs are those supported continuously on the two opposite sides so that the load sare carried along one direction only. Difference between one way slab and two way slab system. Main reinforcement is provided in only one direction. The basic design procedure of a two way slab system has five steps. In reality, sandwich slabs are ribbed slabs with a slab placed both to their upper and lower surface. 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. Simply supported one way slab a rectangular reinforced concrete slab is simplysupported on two masonry walls 250 mm thick and 3. The two classifications are one way slab and two way slab.
Design of one way reinforced concrete slabs class notes and example notes on. Sandwich slabs may have the disadvantage of a larger weight compared to the ribbed ones but on the other hand, they have the advantage that their spans and supports behave in the same proper way. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types. The building is located in seismic zone iii on a site with medium soil.
One way slab is a set of rectangular beams side by side. One way slab what is one way slab design of one way. Slabs are usually used in floor and roof construction. Design the slab following the provisions of the aci code. Here are the steps for the design procedure for one way slab in steps. The slab has to carry a distributed permanent action of 1. The minimum thickness can be determined by many factors. In these slabs on in one direction, the main reinforcements were provided. The thickness of a floor slab must be determined early in design because the weight of the slab is an important part of the dead load of the structure. Design example of one way slab with detailing scribd. Two way slab design by direct design method as per aci 31811.
The program covers wide range of two way slab systems and can be used for more complex slab layouts. The one way slabs are economical up to the span of 3. Ce 433, summer 20 slab design example 1 5 design a one. Slabs may be simply supported or continuous over one or more supports and are classified according to the method of support.
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. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. One way slab is supported on two opposite side only thus structural action is only at one direction. Fundamentals of posttensioned concrete design for buildings part one. Generally, there are two types of slab which are one way and two way slabs. The one way slab floor will act like a beam supported floor distributing the loads onto the beams in onedirection.
Tests of one way posttensioned slabs with unbonded tendons ned h. A rectangular reinforced concrete slab is simply supported on two masonry walls 250 mm thick and. The slab in which is supported to the two opposite sides rcc beams which are responsible to carry the slab load along one direction. Design of slab examples and tutorials by sharifah maszura syed mohsin example 1. Beamless slabs beamless slabs are supported only on columns and are applied mostly in large industrial and public. 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. Two way joist waffle slab design approach and methodology 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. The one way slab is a simple wide shallow rectangular beam as. For better view, please read this post in landscape mode if you are on the mobile device.
Shear strength of beamless slabs usually a controlling factor. There are several methods by which two way slabs can be designed. One way slab design criteria with design example according to aci code. Two way concrete slabs with openings the static system and the design of reinforcement. 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.
A reinforced concrete slab is built integrally with its supports and consists of equal span of 15 ft. Pdf cost optimum design of reinforced concrete simply. The waffle slab is also sometimes termed as ribbed slab system but you would find it interesting to know that ribbed and waffle slab are somehow two different things. Analysis and design of slabs two way civil engineers pk. The paper presents the cost optimization of reinforced concrete simply supported oneway slabs under uniformly distributed load with the nonlinear programming approach. The one way and two way slab systems are the most commonly used floor system in the reinforced concrete structure. If a slab is supported on all the four sides but the ratio of longer span l to shorten span b is greater than 2, then the slab will be considered as one way slab. Pdf behavior of one way reinforced concrete slabs with styropor. All methods are viable provided that the safety and serviceability of the elements are within the acceptable limits. One way and two way slabs one way slabs transfer the imposed loads in one direction only. Slabs having supports on less than four sides can be designed as one way. However, a slab with length breadth ratio of not less than 1.
Pdf oneway slabs subjected to combination of loads failing in. Two way slabs have two way bending unlike one way slab. When one says ribbed slab it is actually a one way spanning system with ribs where as in waffle slab the joists form a two way system. Oneway and twoway slabs oneway slabs transfer the imposed. Design of two way floor slab system comparison of one way and two way slab behavior one way slabs. Comparison of one way and two way slab behavior economic choices one way slab on beams suitable span 3 to 6m with ll 35knm2. Design of reinforced concrete structures ii twoway slabs. The direction in which the load is carried in one way slab is called the span.
The one way slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. If playback doesnt begin shortly, try restarting your device. Design of twoway floor slab system comparison of oneway and twoway slab behavior oneway slabs carry load. The slab is part of an office building and the slab is supporting masonry wallspartitions that are sensitive to excessive deflections. Chapter 3 design of rectangular beams and oneway slabs 12. Pdf design calculation design of one way slab slab s1. Slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs, bridges, and other types of structures. Guide to design of simply supported slabs design of rcc. In one way sab the beams length difference is huge, thats is why the load will not transfer toward the shorter rcc beams. Mar 07, 2017 rcc slab design depends on the on the dimensions of the slab after which the slab is termed as a oneway slab or a twoway slab in the design of rcc structures, column design and beam design are to be done before we start with rcc slab design basic rules followed in the design of simply supported slab. The ratio of longer span l to shorter span b is equal or greater than 2, considered as one way slab because this slab will bend in one direction i. A one way slab is defined for functions of the book as a flexural member with thickness small relative to other dimensions, supporting gravity loads applied normal to and directly above its surface, a span in one direction between parallel supports.
Slab is a common term used to describe the structural elements such as floors and roofs where the thickness of the element is very small compared to the length and. Multistory buildings are very commonly seen in cities. One way concrete slab action is assumed in a ribbed slab with joist beams made of the precast doubletee section, in the ribbed floor with integral beams, and also in hollowblock or hollowcored slabs. Two way slabs are normally supported from four sides. Reinforced concrete design 1 design of slab examples and.
Guidelines for a oneway concrete flooring system brewer. The paper presents the cost optimization of reinforced concrete simply supported one way slabs under uniformly distributed load with the nonlinear programming approach. Although the major reinforcement in one way slab span is in the short direction, yet at the corner, the moment is actual supported by beams at both directions. The slab is 150 mm thick, the beams are 400 mm wide and 600 mm deep and the joists are 300 mm wide and 500 mm deep. For those who do not know what are the des ign requirements of a slab. A one way slab is supported on two opposite sides, so structural action is only ever in one direction. Concrete slabs are commonly divided into the following types. The following example illustrates the example building. Fundamentals of posttensioned concrete design for buildings. Two way slabs page 6 of 14 the pca computer program pcaslab can be used to expedite the design of different slab systems. These slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs or other types of structures. Part two is an example intensive course, with key concepts introduced along.
One way concrete slab metric canada jayrod12 structural 6 jun 14 11. One way slabs are available on concrete slab floors risafloor es. 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. Assume partitions cannot be damaged by deflections. 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. The thickness of one way slab varies between 100mm to 150mm or even more depending upon the span and based on the deflection considerations. For the purpose of this tutorial, enter the general title as sixspan, one way slab. Beams of width and depth are provided on all column lines. Similarly, we can take say, for let us be specific simply supported. One way slab is supported by two parallel beams or walls. Difference between one way slab and two way slab simple.
Download full text pdf download full text pdf download full text pdf. A one way slab is a slab in which its length divided by its breadth is greater than or equal to 2. One way slab design procedure with example design of one. Slab with reinforcement with yield stress, f y, exceeds 60,000 psi measured at a yield strain of 0. Design of reinforced concrete structures ii two way slabs 1 1. Slabs and flat slabs lecture 5 19 th october 2016 contents lecture 5. The slab may be supported by walls, by reinforced concrete beams usually cast monolithically with the slab, by structural steel beams, by columns, or by the ground. Fanella, which appeared in the october 2001 edition of structural engineer magazine.
Analysis and design of slabs one way civil engineers pk. Another comparison is made between results for specimens which have shear span. Reinforced concrete design 1 design of slab examples. Hello, today i am introducing to you an excel spreadsheet program specially created to help design one way continuous reinforced concrete slabs. For b oth one way and two way slab with an example. A monolithic reinforced concrete floor is to be composed of rectangular bays measuring, as shown. No redistribution is allowed when method 1 or method 2 of analysis in section 3. Continuous oneway solid slab concrete structures eurocode. It is unknown, however, if the uniformly distributed loads on solid slab bridges for example, due to dead loads acting over the full width, can. Unless otherwise noted, all referenced table, figure, and.
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