Design of one way and two way slabs, design of staircases. However, the design example in chapter 10 includes calculations showing. Twoway slabs are surface members acting in a both directions. Reinforced thin plate elements are supported over beams, masonry walls or directly over columns. Ce 433, summer 20 slab design example 1 5 design a one. Slabs having supports on less than four sides can be designed as one way.
Oneway and twoway slabs university of asia pacific. One way slab is supported by two parallel beams or walls. Twoway concrete floor slab with beams design and detailing csa a23. When a slab is supported on all four sides and the ratio of long span to short span is equal or greater than two, it will be considered as one way slab. Reinforced concrete design in accordance with as3600 ccaa. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. The basic design procedure of a twoway slab system has five steps. A typical sixspan, one way slab supported on beams,as occurs in parking structures is selected. Pdf performance design of reinforced concrete slabs using.
Two way slabs are normally supported from four sides. Twoway concrete slab on beams floor analysis and design. Define the term slab, one way slab, two way slab, shrinkage and temperature reinforcement, main reinforcement. Design of reinforced concrete structures ii twoway slabs. One way slab here i solve a probleam based on the one way slab, the diamentions are provided in the probleam 1st determine the aspect ration and with respect to the aspect ratio the type of slab. Twoway concrete slab with beams spanning between supports. One way slab oneway slabs are those slabs with an aspect ratio in plan of 2. Analysis and design of slabs two way civil engineers pk. In many cases the slabs are of such proportions and are supported in such way that twoway action. In two way slabs shorter direction strip carry greater %age of load. A single slab with oneway reinforcement rebars will be analyzed with rcsolver. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. Slab supported on two sides and bending takes place predominantly in one direction only is called one way slab.
Nov 15, 2014 one way slab here i solve a probleam based on the one way slab, the diamentions are provided in the probleam 1st determine the aspect ration and with respect to the aspect ratio the type of slab. The slab is supported on 200 mm wide loadbearing block walls at 6000 mm centres. Aug 15, 2016 download code one way slab design spreadsheet. The oneway slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. Two way concrete floor slab with beams design and detailing design the slab system shown in figure 1 for an intermediate floor where the story height 12 ft, column crosssectional dimensions 18 in. Slab with reinforcement with yield stress, f y, exceeds 60,000 psi measured at a yield strain of 0. Assume partitions cannot be damaged by deflections. Design example of one way slab with detailing free download as pdf file. Rectangular beams and oneway slabs page 3 of 9 design of rectangular beams and oneway slabs continued a.
One way and two way slab design aspect the slab provides a horizontal surface and is usually supported by columns,beams or walls. One way and two way slab design aspect online civilforum. If slab is supported on all four sides and r shorter side longer side 2 is one way slab lb stiffness modifiers, should be applied relative to the local axes and the desired direction of oneway action. Reference 5 focused on analysis of two way ribbed slabs with.
Difference between one way and two way slab in terms of. The ratio lb which is less than 2 is known as two way slab. We believe that the quickest way to learn is by actual application of the information. The program covers wide range of two way slab systems and can be used for more complex slab layouts. Oneway slab design spreadsheet civil engineering community. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types.
Calculate the design moment strength of a one way slab 2. One way and two way slabs as floor systems are the most conventional forms of structural floor systems. Chapter 3 design of rectangular beams and oneway slabs 12. Load transfer in a oneway slab, b twoway slab nilson fig. Slabs are usually used in floor and roof construction. Jul 10, 2017 one way concrete slab design part 1 concept explained and minimum slab thickness canadian code duration. This handbook is written around the method in a which is. Learn to design reinforced concrete one way slabs through. The one way slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. Reinforced concrete design 1 design of slab examples. Beam and slab arrangement can be the best example for one way and two way slabs. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3.
Manual for the design of reinforced concrete building. A useful document is the national building industry. Analysis and design of slabs one way civil engineers pk. Reinforcement detailing of reinforced concrete slabs. 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. L center to center distance between the support b depth of slab. The load on the slab is carried by the short span in one direction. Determine the allowable unform live load that a one way slab can sustain 3. The output of the program for the slab in the example is shown in the following pages. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan. One way slab is the most basic and common type of slab.
The ratio of the total costs was found to be within the range 1. Chapter 3 design of rectangular beams and oneway slabs. They may be supported on two opposite sides only fig. One way slabs are those supported continuously on the two opposite sides so that the load sare carried along one direction only. Figure 1 twoway slab with beams spanning between all supports. However, the primary focus of this course covers applications of post tensioning that are typically used in buildings and parking structures, specifically one way slabs, two way slabs, and continuous beams. A 175 mm thick continuous slab is required to support screed, finishes, an office variable action of 2. Bending will take place in the two directions in a dishlike form. Application of lb ratio in first figure slab is supported on two opposite sides only.
The pca computer program pcaslab can be used to expedite the design of different slab systems. Ribbed slab design spreadsheet civil engineering community. Two way slabs have two way bending unlike one way slab. 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. Reinforced concrete design 1 design of slab examples and. 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.
Once design compressive strength of concrete and yield stress of reinforcement are specified, the next steps are. The design procedure for a uniformly loaded one way reinforced slab can be divided in the following steps. Slab supported directly by columns are called flat slab. Effective span of slab shall be lesser of the two 1. Jul 22, 2015 my graduation project with my mate ghassan faris, a two way ribbed slab of clear span of 18 x 25 m was designed by safe 2014, the building is 3storey concrete. Continuous oneway solid slab concrete structures eurocode. Types of one way slab one way slab may be solid hollow ribbed 6. Design example of one way slab with detailing scribd.
I have developed a microssoft excel software for design of a two way rcc slab. May 02, 2017 one way slab is a slab which is supported by beams on the two opposite sides to carry the load along one direction. Whatever may be the width of the slabs it should always be designed for a width of equal to one metre and the same design should be adopted for the rest of the slab. Table 1 results of the analysis for the oneway 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 monolithic reinforced concrete floor is to be composed of rectangular bays measuring, as shown. Design of a two way rcc slab structural engineering. The following example illustrates the example building.
Load transfer in a one way slab, b two way slab nilson fig. The basic design procedure of a two way slab system has five steps. Minimum thickness of oneway ribbed slabs summary of oneway ribbed slab design procedure. The ratio of length to width of one slab should less than 2 otherwise oneway action is obtained, even though supports are provided on all sides. Example design of two way edgesupported solid slab. Design of reinforced concrete structures ii two way slabs 1 1. If slab is supported on all four sides and r shorter side longer side one way slab. Oneway slab supported on beams the objective of this tutorial is to demonstrate the stepbystep procedure of adapt pt to analyze and design a posttensioned continuous slab supported on parallel beams or walls. Design of a two way rcc slab structural engineering forum. 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. This 300 mm deep ribbed slab is required for an office to support a variable action of 5 kn m2 it is supported on wide beams that are the same depth as the slab, as shown in figure 3. Feb 24, 2019 a 175 mm thick continuous slab is required to support screed, finishes, an office variable action of 2. A typical sixspan, oneway slab supported on beams,as occurs in parking structures is selected. Slab may be supported on walls or beams or columns.
Posttensioned concrete is widely used in bridges, shell structures, water tanks, and folded plates. Analysis of two way ribbed and waffle slabs with hidden beams. Generally, there are two types of slab which are one way and two way slabs. Design a simply supported one way slab subjected to dead and live loads 4. However main reinforcement bar and distribution bar in transverse direction. Nov 27, 20 one way slab oneway slabs are those slabs with an aspect ratio in plan of 2. Design of slab examples and tutorials by sharifah maszura syed mohsin. Difference between one way slab and two way slab simple. One way slab is a slab which is supported by beams on the two opposite sides to carry the load along one direction. For uniformly distributed loads of w per square foot of the slab, each strip acts approximately like a simple beam uniformly loaded by its share of w. All information in this document is deemed to be accurate by the european. Two way slab design by direct design method as per aci 31811. Continuous ribbed slabs concrete structures eurocode.
For example, when parallel walls connect to either side of a continuous slab, one way action results. 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. Civilax is the knowledge base covering all disciplines in civil engineering. Oneway slabs transfer the imposed loads in one direction only. The direction in which the load is carried in one way slab is called the span. Design a oneway slab for an exterior bay of a multistory office building using the information specified below. Plan view of floor system assume partitions will not be damaged by deflections. These slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs or other types of structures. Fundamentals of posttensioned concrete design for buildings. Reinforcement detailing of a slab is done based on its support conditions. To enforce one way action, assign small m11 or m22 stiffness modifiers to the slab. These modifiers, available through assign area stiffness modifiers, should be applied relative to the local axes and the desired direction of one way action.
One way slab supported on beams the objective of this tutorial is to demonstrate the stepbystep procedure of adapt pt to analyze and design a posttensioned continuous slab supported on parallel beams or walls. Oneway concrete slab design part 1 concept explained and minimum slab thickness canadian code duration. Oneway simply supported slab analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter. Beams of width and depth are provided on all column lines. Accordingly, main reinforcement is required in the two directions.
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