The following example illustrates the design methods presented in the pca book simplified designreinforced concrete buildings of moderate size and height third edition. Determine moments at critical sections in each direction, normally the negative moments. Difference between one way slab and two way slab system. A rectangular reinforced concrete slab is simply supported on two masonry walls 250 mm thick and. Generally, there are two types of slab which are one way and two way slabs. Design of slab examples and tutorials by sharifah maszura syed mohsin example 1. In this post, we are going to explain how to calculate steel quantity for the slab. In two way slabs, load will be carried in both the directions. In two way slab, the ratio of longer span l to shorter span b is less than 2. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types. One way and twoway slabs one way slabs transfer the imposed loads in one direction only. There are many different methods for analysis of two way reinforced concrete slabs. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan.
Oneway and twoway slabs oneway slabs transfer the imposed. The choice between two way and beamless slabs for more normal situations is. Floor openings in twoway slabs structural engineering forum of. These slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs or other types of structures. If severe deflection limits are imposed, the two way slab will be most suitable, as the introduction of even moderately stiff beams will reduce deflections more than the largest reasonable column capital is able to. Pdf this work investigated the flexural strength and deformation of 14 twoway concrete slabs that were reinforced in two directions with babadua. May 02, 2017 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. Long and short spans of a two way slab are l and l and load on. Jul 02, 2010 lecture series on design of reinforced concrete structures by prof. The effective depth d of two way slabs can also be assumed using cl. Introduction in reinforced concrete construction, slabs are used to provide flat, useful surfaces.
Design procedure steps for one way slab slab design steps. In two way slabs shorter direction strip carry greater %age of load. I have developed a microssoft excel software for design of a two way rcc slab. Analysis and design of two way slabs page 1 chapter 3. For those who do not know what are the des ign requirements of a slab. The reinforced concrete design manual sp1711 is intended to provide guidance and assistance to professionals engaged in the design of castinplace reinforced concrete structures. Design of reinforced concrete structures ii twoway slabs. Design of reinforced concrete structures ii two way slabs 1 1. Twoway concrete floor slab with beams design and detailing. The quantities of the materials are calculated and cost of construction for slabs are determined and compared.
There are two types of slab classification based on the direction of bending occurs in these slabs. The two way slab is designed for both the directions as it bends in both directions. Slab supported on two sides and bending takes place predominantly in one direction only is called one way slab. From the study it is considered that post tension slab is more economical than two way slab. In two way slab main reinforcement is provided along both direction. Slab resting on walls or sufficiently deep and rigid beams on all sides. Dhang, department of civil engineering, iit kharagpur. Here the ratio of longer span of slab to the shorter span of slab is less or equals to 2. The solution per ddm can be found in the two way plate concrete floor system design example. For such cases flat slab with column capitals is very well suited.
Lecture series on design of reinforced concrete structures by prof. Design a simply supported rcc slab for a roof of a hall 3. Slabs are usually used in floor and roof construction. The slab has to carry a distributed permanent action of 1.
Pdf selection of economical span in rcc building researchgate. Designing for shear in slabs when shear reinforcement is not required e. Please read the lauses mentioned in the video while solving the problem. A reinforced concrete slab is a broad, flat plate, usually horizontal, with top and bottom surfaces parallel or nearly so. The two classifications are one way slab and two way slab. Two way rcc slab designing tool in microsoft excel developed by shankar tayal a 3rd year student of school of infrastructure, indian institute of technology, bhubaneswar. The development of these methods was a necessity due to different causes, such as inadequate maintenance, overloading of the reinforced concrete member, corrosion of the steel reinforcement and other different situations that appeared in time. According to the 1995 aci code, all two way 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. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. Redistribution of 10% may be allowed when method 3 or method 4 is adopted.
Following are the rcc slab design and detailing guidelines. Carbon frp strips and glass frp laminates can be used to increase the flexural capacity of two way slabs to an. 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. 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. Two way slab design by direct design method as per aci 31811. Oct032018 two way concrete floor slab with beams design and detailing csa a23. Analysis and design of slabs two way civil engineers pk.
The building is located in seismic zone iii on a site with medium soil. Oneway and twoway slabs university of asia pacific. Here are the steps for the design procedure for one way slab in steps. No redistribution is allowed when method 1 or method 2 of analysis in. The basic design procedure of a two way slab system has five steps. Twoway concrete slab with beams spanning between supports. Twoway slab design panel select boundary condition of slab for upliftment of corners. Rcc structures design multiple choice questions and answers pdf free download for civil students. Two way slab being supported on four sides the load will be carried in both the directions.
Two way reinforced concrete slab design clear longer span of slab please enter the longer span. The basic design procedure of a twoway slab system has five steps. Reinforcement detailing of reinforced concrete slabs. However, the complexity of the generalized approach. Please select the grade of concrete for twoway slab construction. Two way rcc slab designing excel sheet civil engineering. For b oth one way and two way slab with an example. In this video deisgn of two way slabs has been covered using is 456. Click to share on facebook opens in new window click to share on twitter opens in new window click to email this to a friend opens in new window. The two way slab building system is a very effective and common building system. The first reinforced concrete design manual formerly titled aci design handbook was developed in. Reinforced concrete design 1 design of slab examples.
What is the formula for taking load from two way slab for. Reinforced concrete slab design using the empirical method. No redistribution is allowed when method 1 or method 2 of analysis in section 3. If playback doesnt begin shortly, try restarting your device. Reinforced concrete, as a composite material, has occupied a.
Reinforced concrete slab design and detailing guide is456. The following example illustrates the example building. Reinforced concrete design to bs8110 structural design 1 lesson 5 5 4. They may be supported on two opposite sides only fig. The aci 318 building code permits openings of any size in any new slab system, provided that an analysis is performed that demonstrates that both strength and. Unless otherwise noted, all referenced table, figure, and equation. Dec 20, 2017 in this video deisgn of two way slabs has been covered using is 456.
The one way and two way slab systems are the most commonly used floor system in the reinforced concrete structure. Design of two way slabs is 456 limit state method youtube. If the ratio of longer dimension of the slab panel to the shorter dimension is greater than or equal to 2 then it is designed as one way slab. Distribute moments transverse at critical sections to column and middlestrip and if. Two way reinforced concrete slab design clear longer span of slab.
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. Pdf babadua reinforced concrete twoway slabs subjected to. Simply supported one way slab a rectangular reinforced concrete slab is simplysupported on two masonry walls 250 mm thick and 3. Fanella, which appeared in the october 2001 edition of structural engineer magazine. Bending will take place in the two directions in a dishlike form.
A six storey building for a commercial complex has plan dimensions as shown in figure 1. Two way slabs have two way bending unlike one way slab. Bending will take place in the two directions in a dishlike fo. Reinforced concrete design 1 design of slab examples and. Unless otherwise noted, all referenced table, figure, and. Slabs can be designed by direct design method known as ddm and another method for design is coefficient method which is the easier one. This is a part of his project economic design of two way rcc slabs under prof s.
Design of a two way rcc slab structural engineering forum. Pdf strengthening of reinforced concrete twoway slabs. Design of one way and two way slabs, design of staircases. Corners of the two way slab lift up if the slab is not cast monolithically with the supports wallsbeams. For better view, please read this post in landscape mode if you are on the mobile device. Continuous beam if it is the other way, for end span with 1 end fixed and the other continuous. Reinforced concrete design to bs8110 structural design 1. The one way slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. The two way slab will deflect in a dish or saucerlike form under the action of loads.
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