Moreover, for slabs with beams between columns along exterior edges, the value of a f for the edge beam is not to be less than 0. This report does not cover the design of prestressed posttensioned slabs. Sachpazis date 18012014 chkd by date appd by 4 internal column c3 consider the reinforcement concentrated in half width strip over the support depth of reinforcement. Nancy debora assistant professor civil karunya university 2. The flat slab is a twoway reinforced concrete slab that usually does not have beams and girders, and the loads are transferred directly. The system still used todaywhich divides the bays between columns into column strips and middle strips and uses only an orthogonal arrangement of barswas devised in. Eliminating drops results in simpler falsework and formwork arrangements. It is intended for use by designers both of the permanent and temporary works who already have basic understanding of structural behaviour. Provides information and current best practice on the design and construction of reinforced concrete flat slabs in accordance with eurocode 2 and the national structural concrete specification. However, the span influencing their design is the longest and they require more steel compared to twoway slabs. The reinforcement for the column strip was design for the direction from easttowest only. Method of statement construction of flat concrete floor for. Experimental and numerical investigation on the punching. In this study fe analysis of flat slabs is proposed.
The basic spaneffective depth ratios are multiplied by 0. Flat slabs are easy to build and have through their smaller depth, economical and architectural advantages compared to slab with beams. Abstract the punching shear design procedures according to current codes e. Flat slabs are thought to result in zones of broad, diffuse deformation in the upper plate located far landward from the trench. The slab directly rests on the column and load from the slab is. Method of statement construction of flat concrete floor. Flat slabs system of construction is one in which the beams used in t he conventional methods of constructions are done away with. A more detailed guide to the design of pt floors can be found in the concrete societys technical report 43 tr43. The present objective of this work is to compare behavior of flat slab with old traditional two way slab. Punching shear behavior of concrete flat slabs in elevated. Shear capacity of reinforced concrete flat slabs made with high. Civildigital powerpoint presentations building technology flat slab floor system.
The design procedure set forth in that publication had at that time been in use by the author for about 15 years. Flat slabs are those which are directly supported on columns. Design of slab examples and tutorials by sharifah maszura syed mohsin example 1. A slab which are directly rested on columns or column head without beams are known as flat slab there are four type of flat slabe 1. After this publication, it was subsequently adopted by the uniform building. Punching shear behavior of reinforced concrete flat slabs with a. Dhang, department of civil engineering, iit kharagpur. Advantages and disadvantages of flat slabs civil engineering.
The beams reduce the available net clear ceiling height. These differences are attributed to the stiffening effect provided by the steel profiles that constitute the punch ing shear reinforcement. Design of flat slab with edge beams by direct design method 16 14 14 3 b c 1 c 2 c 3 c 4 3 1 c 5 c. A total of 79 tested slabs without shear reinforcement were selected from literature to study the treatments by these methods. Beamless slabs beamless slabs are supported only on columns and are applied mostly in large industrial and public buildings. Design considerations for reinforced concrete flat slab floor. Other drawbacks of flat slabs are vulnerability to punching shear failure and higher deflections. Introduction to flat slabs modelling of reinforced concrete. Flat slabs are less labour intensive, simplify the installation of services and can accommodate more floors within restricted heights. This work compares experimental results of six twoway reinforced concrete ribbed flat slabs with rectangular holes close to the column and. Advantages and disadvantages of flat slabs advantages and disadvantages of flat slabs a flat slab is a oneway or twoway system with thickenings in the slab at the columns and load bearing walls called drop panels figure 9. General a slab is a flat two dimensional planar structural element having thickness small compared to its. This method is used even today for the design of flat slabs and flat plates and is known as the direct design method. Flat slab sized for punching shear and deflection additional reinforcement added to span steel to reduce deflections typically 25% extra on a 7.
Punching strength of reinforced concrete flat slabs without shear. Optimum design of reinforced concrete flat slab with drop. 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. Design considerations for reinforced concrete flat slab. List of tables 10 early load tests on flat slabs, dimensions and loading arrangements 0 0 0 0 0 0 0 0 0. Findotek date rev no prepared by checked by approved by remarks. Beside this, due to shear problems at column heads, the thickness of flat slab is greater. Flat slab analysis, design and detailing pdf civil. For fy between the values given in the table, minimum thickness is determined by linear interpolation. Tech student, 2assistant professor department of civil engineering, narayana engineering and technical campus, jafferguda, batasingaram, hayathnagar, telangana, india. Flat slab flat slab are also known as beamless slab, is a type of slab in which the flooring slab is directly supported on columns without the agency of beam or girders. Pdf download for punching shear behavior of concrete flat slabs in.
Slabs may be simply supported or continuous over one or more supports and are classified according to the method of support. Oct 10, 2017 16 videos play all 22 slabs flat slabs 2016. Design for crack control is achieved by minimising the spacing between bars. Shear is critical in flat slabs the design shear force veff is the column reaction vt multiplied by 1. View homework help flat slabs from cven 4301 at university of new south wales. The modification for tension reinforcement is based on the total moment at midspan and the average of the middle and column strip reinforcement. For these case studies we have created models for twoway slabs and flat slab without shear wall for each plan. Jul 18, 2014 civildigital powerpoint presentations building technology flat slab floor system.
Flat slab seminar report, ppt, pdf for civil engineering. Simply supported one way slab a rectangular reinforced concrete slab is simplysupported on two masonry walls 250 mm thick and 3. In addition to this, the shear capacity can also be reduced in particular around the column head where large shear forces can develop. Keywordsflat slab, reinforced concrete, structural optimization, punching shear stress, slab size, drop panel size. However, flat slabs have a lower stiffness in comparison to a beamcolumn floor plan which can lead to relatively large deflections. Comparative study of reinforced concrete flat slabs with.
Flat slab types of flat slab design and its advantages. Flat slabs carried on columns and edge beams or walls with no interior beams slabs may be solid of uniform thickness or ribbed with ribs running in one or two directions. Also explore the seminar topics paper on flat slab with abstract or synopsis, documentation on advantages and disadvantages, base paper presentation slides for ieee final year civil engineering ce or ieee civil construction btech, be, mtech students for the year 2015 2016. Jul 02, 2010 lecture series on design of reinforced concrete structures by prof. For spans from 5 to 9 m, thin flat slabs are the preferred solution for the construction of insitu concrete frame buildings where a square or nearsquare grid is used. Comparative study of reinforced concrete flat slabs with and. It should be noted that solid flat slabs with a flat soffit are the most popular. Flat slab types of flat slab design and its advantages flat slab is a reinforced concrete slab supported directly by concrete columns without the use of beams. This article provides information on how to scheme a pt slab and how the use of posttensioning affects the rest of the structure. Guide to the design and construction of reinforced. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems. Dec 06, 2012 provides information and current best practice on the design and construction of reinforced concrete flat slabs in accordance with eurocode 2 and the national structural concrete specification. The system still used todaywhich divides the bays between columns into column strips and middle strips and uses only an orthogonal arrangement of.
Flat slab is defined as one sided or twosided support system with sheer load of the slab being concentrated on the supporting columns and a square slab called drop panels. Punching strength of flat slabs with and without shear. Twoway concrete flat slabs provide a number of benefits for office. Lecture series on design of reinforced concrete structures by prof. Flat slabs example 2 flat plate slab with edge beams.
Punching shear resistance of flat slabs with opening dr samal m. Introduction to flat slabs modelling of reinforced. The slab has to carry a distributed permanent action of 1. Posttensioned pt concrete floors are now widely used in the uk, particularly for highrise buildings. Seismic analysis of flat slab by using etabs international journal. Flat slabs design is appropriate for most floor situations and is also suitable for irregular column layouts, curved floor shapes, ramps etc. These structures are known to be an elegant building system which is evidenced by the absence of beams and by its. Results of latest experiments have revealed that the maximum punching resistance defined from crushing of concrete struts at the perimeter of a column is an insufficient criterion for limitation of maximum shear forces at the vicinity of the columns. This paper presents both experimental and analytical investigations undertaken to evaluate the effect of openings adjacent to columns on the punching capacity of flat slabs.
Beside this, due to shear problems at column heads, the thickness of. The benefits of choosing flat slabs include a minimum depth solution, speed of construction, flexibility in the plan layout both in terms of the shape and column layout, a. Guide to the design and construction of reinforced concrete. Rashied faculty of engineering, university of sulaimani kurdistan of iraq abstract there are numbers of methods have been proposed to evaluate the influence from opening on punching shear resistance in flat slabs in the vicinity of columns. This pdf file contains a chapter of 23 pages with various aspects of flat slabs including four example of flat slab design. Pointlike supports of flat slabs c d c column without column head d column with fungiform column head in flat slabs the total load intensity should be carried in both perpendicular directions. Department of mechanics, materials and structures english.
Later in 1914, nicholas proposed a method of analysis of flat slabs based on simple statics. Introduction flat slab structural systems have a large applicability due to their functional and economical advantages. Twoway concrete slabs with openings the static system and the design of reinforcement. Experimental study on the effective width of flat slab structures under. Comparative study of flat slab with old traditional two. In 1914 eddy and turner were first wrote on flat slabs, the flat slabs directly rests on columns and walls over other forms of construction and advantages are better lightning, lower cost, greater neatness of appearance, rapidity of construction and increased safety is universally. Comparative study of flat slab with old traditional two way slab. Slabs and flat slabs lecture 5 19 th october 2017 contents lecture 5 designing for shear in slabs including punching shear detailing solid slabs flat slab design includes flexure worked example exercise punching shear. Explore flat slab with free download of seminar report and ppt in pdf and doc format. Flat slabs are used by engineers in many building due to its advantages over other reinforced concrete floor system in different cases.
Reinforced concrete design 1 design of slab examples and. Figure 6 gives a modification coefficient which will adjust the cantilever length for smaller slabs depending on the slab size. A flat slab is a twoway reinforced concrete slab that usually does not have beams and girders, and the loads are transferred directly to the supporting concrete columns. For spans over 9 m posttensioning should be considered. Example 2 flat plate slab with edge beams design suitable flexural reinforcement for the office floor slab. Flat slab analysis, design and detailing pdf civil engineering. Concrete slabs are commonly divided into the following types.
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