The recommendations derived from these and other studies vary from extremely light to extremely heavy. One way slab being supported on two opposite sides only leads to the structural action in single direction. They may be supported on two opposite sides only fig. One way spanning slabs should be treated as beams of unit width and chapter 2 should be followed except for minimum shear reinforcement. Design procedure steps for one way slab slab design steps. In two way slabs, load will be carried in both the directions. Analysis and design of slabs two way, two way edge supported slabs, design methods, aci coefficient method, minimum depth for deflection control,aci example. Two way 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.
Punching shear reinforcement on slab 39 one way joist 41 two way slab analyzed by the direct design method 47 development length of bars in tension 50. In 1914 nichols used statics to compute the total moment in a slab panel. However, the aciasce committee 4216 allows the design strength to increase when the reinforcing shear v c is 14 by applying a stud and the maximum value can be increased up to 23 in eq. Basic steps in two way slab design choose layout and type of slab. Chapter 18 concrete slab structures january 2019 188 18. Fanella, which appeared in the october 2001 edition of structural engineer magazine. How to design concrete structures using eurocode 2. In any span, the max cable sag, zd depends on the concrete cover requirements and the tendon dimensions. Two way slab design by direct design method as per aci 31811. The example presented here is for two way posttensioned design. In the design of twoway reinforced concrete slabs, e.
Oneway and twoway slabs oneway slabs transfer the imposed. One way concrete slab design part 1 concept explained and minimum slab thickness canadian code duration. Introduction concrete slabs on grade are a very common type of concrete construction. Reinforced concrete ribbed slabs with widebeam lajes. Chapter 3 design of rectangular beams and oneway slabs.
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. Asce, secb course content slab on grades construction. 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. Pdf a simplified method for designing rc slabs under. It was actually the widespread use of the posttensioned slab onground which induced this interest in design procedure and in many studies of reported slab failures. A detailed explanation will be given of the checksto be carried out, the aspects to be considered in the design and the construction procedures and sequences of a posttensioned slab. The construction and design of concrete slabs on grade. Analysis and design of slabs two way civil engineers pk. 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. Define the term slab, one way slab, two way slab, shrinkage and temperature reinforcement, main reinforcement. Determine moments at critical sections in each direction, normally the negative.
Department of mechanics, materials and structures english courses reinforced concrete structures code. Flat plate concrete floor system does not use beams between columns or. A reinforced concrete slab is built integrally with its supports and consists of equal span of 15 ft. The bearing of the slab on the supporting walls may be taken as. Bending will take place in the two directions in a dishlike form.
His analysis suggested that the current slab design. There are several methods by which two way slabs can be designed. The efficiency of this method is shown by a numeric example at the end of the paper. Design of reinforced concrete structures ii twoway slabs. The efficiency of this method is shown by a numeric example at the. Fundamentals of posttensioned concrete design for buildings part one. 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. The construction and design of concrete slabs on grade d. In a oneway spanning slab the area of each bay exceeds 30 m2. Examples to aci, aisc and asce interactive calculation templates to us codes u. Ec2 webinar autumn 2016 lecture 52 designing for shear in slabs when shear reinforcement is not required e. Introduction, definitions flat slabs are two way slabs supported by pointlike supports.
Design of reinforced concrete structures ii two way slabs 1 1. 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. Design of cantilever slab spreadsheet engineering books. One way slabs are such slabs in which the loads are shared only by the shorter direction of the slab. This design should always be used unless approval to use a thinner deck is obtained from the state bridge engineer. Unless otherwise noted, all referenced table, figure, and equation. Types of slab slabs are plate elements forming floors and roofs in buildings which. Oneway and twoway slabs university of asia pacific.
A six storey building for a commercial complex has plan dimensions as shown in figure 1. They are projections from wall face of lintel beams or floor slabs. Slab design, bs 8110 slab design, how to determine ultimate load for slabs, how to check for deflection in slabs, how to calculate for dead load, how to calculate for lever arm, basics of slab design, how can i design a 2 way spanning slab, building contractor secrets secrets you should know as a. Slab design reading assignment chapter 9 of text and, chapter of aci31802. Analysis and design of two way slabs page 1 chapter 3. Design the 4 marked slab panels of an ordinary house. Continuous one way slab figure 1 shows a clear area of 12 m x 8. Department of mechanics, materials and structures english. Pdf file contains a chapter named design of flat slabs of 23 pages with various aspects of flat slabs including four example of flat slab design. 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 slab is to be finished with 25 mm thick cement concrete flooring. Twoway joist concrete slab floor waffle slab system. The following example illustrates the example building. Reinforced concrete design 1 design of slab examples.
Here ratio of longer span of slab to the shorter span of slab is greater than 2. Sachpazis date 18012014 chkd by date appd by 1 flat slab design to bs8110. History of two way slabs the feeling at start that only part of the load to be carried in each direction, so that statics somehow did not apply to slab construction. A slab strip of unit width is analysed using simple beam theory. 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. These types of slabs are used in constructing floors of multi storeyed building. All methods are viable provided that the safety and serviceability of the elements are within the acceptable limits. Reinforced concrete design 1 design of slab examples and. Design the slab following the provisions of the aci code. Fundamentals of posttensioned concrete design for buildings part one a suncam online continuing. The basic design procedure of a two way slab system has five steps. Punching of flat slabs design for shear at th e column heads. Here are the steps for the design procedure for one way slab in steps. Example design of two way edgesupported solid slab.
Example design combinations for deflection quasipermanent derived for. Ce 433, summer 20 slab design example 1 5 design a one. Even while designing they are considered as one slabs with cantilever fixed or continuous at supports. The following example illustrates the design methods presented in aci 31805 and ibc 2003. The best flat slab analysis, design and detailing related pdf and slides are provided here altogether. In this article, it is assumed that slab thickness is determine but calculation of column and middle strips is. Pdf designing twoway slabs under transverse concentrated loads is one of the challenges in designing. One way slabs normally design as a beam with cables running in the direction of the span at uniform centres. A monolithic reinforced concrete floor is to be composed of rectangular bays measuring, as shown. Step 2 design forces draw panel of slab and indicate maximum design moments, shears and in. Design of slab examples and tutorials by sharifah maszura syed mohsin example 2. Beams of width and depth are provided on all column lines. Framing dead load selfweight superrimposed dead load 25 psf partitions, me, misc.
One way slab design procedure with example design of one. Twoway slab analysis and design using equivalent frame method efm. The building is located in seismic zone iii on a site with medium soil. Asc steel deck is leading the way in innovation with ongoing. The lateral loads are independently resisted by shear walls. Flat slab analysis, design and detailing pdf civil. When zd is determined, the prestressing force required to balance an. On the other hand, in the design criteria, there are two types of actions beam action and two way action, by dividing the slabs.
A reinforced concrete slab is a broad, flat plate, usually horizontal, with top and bottom surfaces parallel or nearly so. Introduction in reinforced concrete construction, slabs are used to provide flat, useful surfaces. For those who do not know what are the des ign requirements of a slab. One way and two way slabs one way slabs transfer the imposed loads in one direction only.
Introcduction slab in which the deflected surface is predominantly cylindrical termed as one way slabs spanning in the direction of curvature. Before the start of two way slab design, slab depth should be determined in addition to specify column strips and middle strips. So, main reinforcement is provided in both direction for two way slabs. The corner reinforcement can be arrange in two way as shown below. Table 5 showed that none of the slabs failed by punching shear. Part two is an example intensive course, with key concepts introduced along. Allowable stress design or working stress design wsd 2. 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 service live load is 100 psf and 4000 psi concrete is specified for use with steel with a yield stress equal to 60000 psi. Plan view of floor system assume partitions will not 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 same is true for a two way slab or any other floor system. Minimum thickness for solid one way slabs unless deflections are calculated for slab not supporting or attached to partitions or other construction likely to be deamaged by. The slab is supported on beams of size 225 x 500 mm spaced at 4.
The trial depth is selected based on spandepth ratio of 7, as in is. The two classifications are one way slab and two way slab. Design of reinforced concrete structure one way slab presented by md. The execution of the design will be explained with reference to an example. Rectangular beams and one way slabs page 2 of 9 two methods. 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.
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