Design of slab examples and tutorials by sharifah maszura syed mohsin example 1. A finite element model may be created to analyse a complicated loading arrangement. University of south florida scholar commons graduate school theses and dissertations usf graduate school 112011 oxygen diffusion characterization of frp. Design compressive normal force in the concrete flange. The design procedure set forth in that publication had at that time been in use by the author for about 15 years. L center to center distance between the support b depth of slab. However, the complexity of the generalized approach.
Design of reinforced concrete structures ii twoway slabs. 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. Floor slabs can range from a simple residential basement slab to a heavyduty industrial floor. Slabs are usually used in floor and roof construction.
Also its deflection is managed by checking its spandepth ratio. A reinforced concrete slab is built integrally with its supports and consists of equal span of 15 ft. Analysis and design of twoway slabs page 1 chapter 3. 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. Pdf distribution of moments in reinforced concrete slabs. Dimensioning according to the current provisions in csa a23. Distribution of moments in reinforced concrete slabs with. Reinforced concrete design 1 design of slab examples. Concrete slabs are commonly divided into the following types. Difference between one way slab and two way slab system the one way and two way slab systems are the most commonly used floor system in the reinforced concrete structure.
It assumes that the area under the slab as well as the slab edge are insulated to a minimum of r 10 rsi 1. Feb 07, 2014 a short tutorial showing how the shear capacity of a simply supported slab is checked using ec2. Over 360 technical changes have been incorporated in this new edition. Flat slab analysis, design and detailing pdf civil. The structural modeling used in most commercially available software, where stems are considered as disjointed from the topping slab does not deliver the advantages associated with waffle slab slab construction. 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.
Slab design is comparatively easy when compared with the design of other elements. In both of them, the shear resistance has to be determined by means of slab tests, however the total number of test can be considerably reduced, because once the longitudinal strength. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. Background of simple design method 12 membrane forces along yield lines 2 simple design method of reinforced concrete slabs at 20 c k,b are parameters defining magnitude of membrane forces, n is a factor deduced from yield line theory, k is the ratio of the reinforcement in the shorter span to the reinforcement in the longer span. The national research council of canada and usasks vidointervac collaborate to advance development of vaccine against covid19 20200512 09. For slabs spanning in both directions published tables and charts should be used to find bending moment and shear per unit width of slab. The 2012 edition of the reinforced concrete design manual sp1711 was developed in accordance. Sachpazis date 18012014 chkd by date appd by 1 flat slab design to bs8110. Asce, secb course content slab on grades construction. Generally, there are two types of slab which are one way and two way slabs. Oneway slabs normally design as a beam with cables running in the direction of the span at uniform centres. In case of one ways slabs, the aci approximate analysis is applicable to one way slab system where a one way slab is continuous with a one way slab. Design of reinforced concrete structures ii twoway slabs 1 1.
Frostprotected shallow foundations fine homebuilding. Oneway simply supported slab analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter. Tower silos, tall, bulletshaped farm structures, are used to store forage crops for feeding cattle. After this publication, it was subsequently adopted by the uniform building code ubc as. Here, we have tried to gather various reading materials available in the web about flat slab floor system in one place. N c,f 0,85 f cd b h c reduced plastic moment resistance of the sheeting. 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.
Sep 03, 2011 reinforced concrete sk 33 section through slab showing stress due to moment. When zd is determined, the prestressing force required to balance an. Bending will take place in the two directions in a dishlike form. Chapter 8 design of posttensioned slabs on grade, pg. 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. Master of science and hereby certify that, in their opinion, it is worthy of acceptance. Member design reinforced concrete two way spanning slab bs8110 v2015.
The locations of the strips are usually governed by the locations of the slab supports. A slab strip of unit width is analysed using simple beam theory. Two way slab design by direct design method as per aci 31811. The design procedure specifies the thickness and width of the horizontal wing of insulation that is to be installed around the perimeter of the slab ongrade. In addition to general ultimate and serviceability limit state design issues, practical design considerations such as the formation of holes in the slab, support details, fire protection, and attachments to the slab are discussed. Reinforced concrete design 1 design of slab examples and. The design of composite slabs and beams is discussed in detail in relation to the eurocodes and bs 5950. Rc slab design ec2 worked example shear and deflection. A six storey building for a commercial complex has plan dimensions as shown in figure 1. Reinforced concrete slabs are used in floors, roofs and walls of buildings and as the decks of bridges. A civil engineer must know all the aspects regarding the flat floor system. These slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs or other types of structures. 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. Following are the rcc slab design and detailing guidelines.
Design of one way slab usd oneway slabs are those slabs having supports along one way only figure 1a or slabs having supports having on all sides but with an aspect ratio in plan of 2. Here are the steps for the design procedure for one way slab in steps. Reinforced concrete slab design and detailing guidelines for depth of slab, loads on slab, reinforcement guide for oneway and twoway slabs as per is 456. The results of the study show that the slab can be successfully used for residential buildings as it meets all the requirements and demands fewer materials. The national building code of canada 2015 nbc, published by nrc and developed by the canadian commission on building and fire codes, sets out technical provisions for the design and construction of new buildings. January 01, 2020 purpose this manual documents policy on bridge design in texas. Structural details of slab culverts 3 for spans less than 3. Accordingly, main reinforcement is required in the two directions. 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. The slabs having supports on all sides acts as two way. It also applies to the alteration, change of use and demolition of existing buildings.
The design of twoway slabs based on the direct design method and the equivalent frame method in accordance with the aci31805 design code is limited for slabs. Depending on the boundary condition and the properties of the slabs, methods of finding bending moment is expressed in the bs 8110 part 01 as follows. The cross section of the profiled sheeting is shown in fig. Explanatory text was added to each chapter, while maintaining relevant design aids and illustrative examples. The four corners of the slab panel are supported, e. The thermal resistance and width of the perimeter insulation is specified. According to the 1995 aci code, all twoway reinforced concrete slab systems, including edge supported slabs, flat slabs, and flat plates, are to be analyzed and designed according to one unified method, such as direct design method and equivalent frame method. Normal stresses are as given for working stress design in aci code 31863. The slab has to carry a distributed permanent action of 1. The design of twoway slabs based on the direct design method and the equivalent frame method in accordance with the aci31805 design code is limited for slabs with beams in column lines only.
Using aashto lrfd bridge design specifications 4th ed. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems. Oneway and twoway slabs university of asia pacific. Design of reinforced concrete structures ii twoway slabs 8 c. Extend horizontally from center line column at least 16 center line span. C 5 is the slope correction coefficient co is the consolidation correction coefficient as an example. A reinforced concrete slab is a broad, flat plate, usually horizontal, with top and bottom surfaces parallel or nearly so. The construction and design of concrete slabs on grade. The construction and design of concrete slabs on grade d. Bridge approach slab analysis and design incorporating elastic soil support presented by. The building is located in seismic zone iii on a site with medium soil.
There are several benefits to this kind of foundation, but dont make sense everywhere. Reinforced concrete slab design and detailing guide is456. After this publication, it was subsequently adopted by the uniform building. Member design reinforced concrete two way spanning.
Design of slab for flexure 067 m unit width of slab. Design and detailing of rectangular flat slab panels. Structural steel composite slab 1 of 7 rev design project. Frostprotected shallow foundations usually consist of a monolithic thickedged slab wrapped with vertical and horizontal rigidfoam insulation. These materials are originally located at different websites. For this slab, panel a has two discontinuous exterior edges and two continuous interior edges, panel b has one discontinuous and three continuous edges, while the interior panel c has all edges continuous. Standard for the structural design of composite slabs and. Tests of flat plate structures indicate that, in most practical cases, the capacity is governed by shear. The oneway slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. Moment and shear transfer between columns and concrete slabs. Reinforced concrete slab design using the empirical method bridgesight solutions for the aashto lrfd bridge design specifications bridgesight software tm creators of effective and reliable solutions for the worlds bridge engineers 2688 venado way rescue, ca 95672 phone. 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. Cross sectional constant defines torsional properties c x. For those who do not know what are the des ign requirements of a slab.
Oxygen diffusion characterization of frp composites used. They may be supported on two opposite sides only fig. The axial force, moments and shears for a particular strip are recovered from the analysis on the basis of the wood armer tech. Twoway joist concrete slab floor waffle slab system.
The first tower silos, constructed about 40 years ago, were small, predominantly wooden structures although a few were made of concrete. Chapter 3 design of rectangular beams and oneway slabs 12. Oneway and twoway slabs oneway slabs transfer the imposed loads in one direction only. The recommendations derived from these and other studies vary from extremely light to extremely heavy. Many of these earlier design aids intended to carry out relatively simple design calculations were eliminated in the sp1709 edition. Introduction concrete slabs on grade are a very common type of concrete construction. Point load this problem is designed to demonstrate how to check the ability of a composite slab to carry a 3000 lb point load over an area of 4. The first stage of the design is finding the bending moment of the slab panels. Twoway flat plate concrete floor system analysis and design. Tensioning building structures march 12, 2020 2020 educode las vegas. Design procedure steps for one way slab slab design steps. Beamless slabs beamless slabs are supported only on columns and are applied mostly in large industrial and public buildings.
Find the following parameters for design moments in step 2 per unit width step 4 note. Standard for the structural design of composite slabs and standard practice for construction and inspection of composite slabs asce ansiasce 391 and 991 isbn print. In any span, the max cable sag, zd depends on the concrete cover requirements and the tendon dimensions. The lateral loads are independently resisted by shear walls. The floor system of a structure can take many forms such as in situ solid slabs, ribbed slabs or precast units. 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. Difference between one way slab and two way slab system. Shear design in flat plates and flat slabs when twoway slabs are supported directly by columns, as in flat slabs and flat plates, or when slabs carry concentrated loads, as in footings, shear near the columns is of critical importance. Introduction in reinforced concrete construction, slabs are used to provide flat, useful surfaces. Effective span of slab shall be lesser of the two 1. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types. Composite slab worked example 1 made by sssr date 140500 structural steel design project calculation sheet checked by pu date 080800 check the adequacy of the continuous composite profiled deck slab with spans of 3. The two classifications are oneway slab and twoway slab. Pdf 3 analysis and design of deck slab satya narayana.
Flat slab system is an important division of concrete floor system. Reinforced concrete slab design using the empirical method. Powered by the equivalent frame method of analysis and design per latest american aci 31814 and canadian csa a23. For lower loads they can have constant thickness and are called flat slabs or flat plates, see figure 1.
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