The depth of the slab shall be assumed from the span to. The simplest routine structural element for illustration of design provisions in the code is the one way slab. Determine moments at critical sections in each direction, normally the negative moments at. Reinforced concrete oneway slab design question integrity. Difference between one way and two way slab in terms of. 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.
Jan 16, 2017 in this post, i will go over the fourth example in our course that covers the analysis and design of reinforced concrete one way slabs. Load transfer in a oneway slab, b twoway slab nilson fig. The one way slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. Rectangular beams and oneway slabs page 3 of 9 design of rectangular beams and oneway slabs continued a. 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. One way and two way slab design aspect online civilforum. The different steps of the design are explained below. Two way slabs have two way bending unlike one way slab. Workshop on application of new seismic code for highway bridges irc. For example, when parallel walls connect to either side of a continuous slab, oneway action results. Design beams if any, using procedures you learned in civl.
We aim to close the gap to the industry by improving the awareness about latest trends in civil engineering. One way slab reinforcement details online civilforum. Designing a simply supported reinforced concrete one way slab. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. The spslabspbeam manual command opens spslabspbeam manual in the default pdf viewer. Chapter 3 design of rectangular beams and oneway slabs. The goal of optimization is to find the values of the variables in the process that yield. The following example illustrates the example building. Jan 15, 2017 in this post, i will go over the third example in our course that covers the analysis and design of reinforced concrete one way slabs. Reinforced concrete ribbed slabs with widebeam lajes.
One way slab here i solve a probleam based on the one way slab, the diamentions are provided in the. Optimum cost design of renforced concrete one way slabs. Two way slabs page 6 of 14 the pca computer program pcaslab can be used to expedite the design of different slab systems. The ratio lb which is less than 2 is known as two way slab.
Figure 1 twoway slab with beams spanning between all supports. Twoway concrete floor slab with beams design and detailing. They made an effort not only to solve my problems arising during the writing process but also to allow me experience the professional research work. Static and fatigue shear strength of reinforced concrete slabs. Influence of longitudinal reinforcement strength on oneway slab deflection article pdf available in canadian journal of civil engineering 3510. May 15, 2020 one way slab is a slab which is supported by beams on the two opposite sides to carry the load along one direction. The goal of this reinforced concrete design example is to design a simply supported reinforced concrete one way slab subjected to dead and live loads per aci code 31811. Sep 04, 2014 the structure is one way, and the loads are carried by the slab in the deflected short direction fig2a. Bending will take place in the two directions in a dishlike form. The aim of this reinforced concrete design example is to design a continuous reinforced concrete one way slab subjected to dead and live loads per aci code 31811. 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. Slabs are usually used in floor and roof construction. Ce 433, summer 20 slab design example 1 5 design a one.
Design of reinforced concrete structures ii two way slabs 1 1. Reinforced concrete slab design and detailing guidelines for depth of slab, loads on slab, reinforcement guide for one way and two way slabs as per is 456. Minimum thickness of one way ribbed slabs summary of one way ribbed slab design procedure. One way and two way slab design aspect the slab provides a horizontal surface and is usually supported by columns,beams or walls. For those who do not know what are the des ign requirements of a slab. Shear due to loads always must be less than the shear strength of concrete. A one way slab is defined for purposes of this book as a flexural member with depth small relative to other dimensions, supporting gravity loads applied normal to and directly over its surface, spanning in one direction between parallel supports, and reinforced for flexure. Pdf influence of longitudinal reinforcement strength on one. Slab shear strength twoway shear check the adequacy of slab thickness for punching shear twoway shear at an interior column figure 4. Difference between one way slab and two way slab system. 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. The two classifications are oneway slab and twoway slab. To enforce one way action, assign small m11 or m22 stiffness modifiers to the slab.
Such designs include corrugated slabs and ribbed slabs. Oneway slabs are required to have slab edges that are parallel to the beam edges just like a beam supported floor. Flat slab difference between one way slab and two way slab. Slabs having supports on less than four sides can be designed as one way. 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. In twoway slabs shorter direction strip carry greater %age of load. Design of concrete structures 14th edition, 2009, by arthur h. Reinforced concrete slab design and detailing guide is456. These modifiers, available through assign area stiffness modifiers, should be applied relative to the local axes and the desired direction of oneway action. These slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs or other types of structures. Customer acknowledges that the registration process for the software results in. Aug 09, 2014 civilax is the knowledge base covering all disciplines in civil engineering. Once design compressive strength of concrete and yield stress of reinforcement are specified, the next steps are followed. A concrete slab is a common structural element of modern buildings, consisting of a flat, horizontal surface made of cast concrete.
Assume partitions cannot be damaged by deflections. Load distribution pattern in twoway slab is in four sides. Load transfer in a oneway slab, b twoway slab nilson. Load transfer in a one way slab, b two way slab nilson fig. 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. One of the most important decisions in the building design process. Generally, there are two types of slab which are one way and two way slabs. Oneway slab design spreadsheet civil engineering community. Generally if one side is more than double of the other one, the slab will be one way.
These modifiers, available through assign area stiffness modifiers, should be applied relative to the local axes and the desired direction of one way action. Here are the steps for the design procedure for one way slab in steps. Reinforced concrete, 2014, 9th edition, aci 31811 code edition, by jack c. Plan view of floor system assume partitions will not be damaged by deflections. Oneway shear analysis of longitudinal beams and slabs. One way slabs are required to have slab edges that are parallel to the beam edges just like a beam supported floor. Now in one way slab as one side is bigger than the other side most of the load is carried by that side only so providing main reinforcement corresponding to that load carrying. Design of reinforced concrete structures ii twoway slabs. Define the term slab, one way slab, two way slab, shrinkage and temperature reinforcement, main reinforcement. Difference between one way slab and two way slab simple. 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. In concrete slab floors, the draw slab edge tool allows you to draw any shaped edge which is very powerful for. We assume that the verandah slab is a two way slab instead of one way slab in order to calculate mb,neg now, using moment coefficient method for analysis.
In oneway slab, main steel is provided in one span. Designing a continuous one way reinforced concrete slab per. To enforce oneway action, assign small m11 or m22 stiffness modifiers to the slab. Chapter 3 design of rectangular beams and oneway slabs 12. In sap program, the model has been divided to frame elements to represent ribs and beams and shell elements to represent the slab and solid part. Load distribution pattern in oneway slab is in one direction for shorter span. Mathematical structural analysis of one way ribbed slabs was introduced in this paper.
The output of the program for the slab in the example is shown in the following pages. 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. A one way slab has momentresisting reinforcement only in its short axis, and is used when the moment in the long axis is negligible. Twoway slabs page 6 of 14 the pca computer program pcaslab can be used to expedite the design of different slab systems. Select reinforcing bars for the slab and concentrate bars near the column, if necessary 5. Design of a two way rcc slab structural engineering. Mar 10, 2018 design steps for rcc one way slab by prof. If slab is supported on all four sides and r shorter side longer side 2 is one way slab lb pdf available in canadian journal of civil engineering 3510. Steelreinforced slabs, typically between 100 and 500 mm thick, are most often used to construct floors and ceilings, while thinner mud slabs may be used for exterior paving see below. Types of one way slab one way slab may be solid hollow ribbed 6.
If slab is supported on all four sides and r shorter side longer side one way slab. Oneway and twoway slabs oneway slabs transfer the imposed. In many domestic and industrial buildings, a thick concrete slab supported on. Slab resting on walls or sufficiently deep and rigid beams on all sides.
The program covers wide range of two way slab systems and can be used for more complex slab layouts. Determine the area of steel required in the slab at critical sections for column and middle strips. Aug 03, 2016 the design steps have been presented in the following question how do i degisn two way slab. Analysis and design of slabs two way civil engineers pk. Nonreinforced slabs may also be considered one way if they are supported on only two opposite sides i.
In case of slabs thin members, no need of even minimum shear reinforcement. The direction in which the load is carried in one way slab is called the span. One way slab is a slab which is supported by beams on the two opposite sides to carry the load along one direction. One way slab are slab in which one side is very large compared to the other one. In two way slabs shorter direction strip carry greater %age of load. Slab is checked for deflection shear and development length. One way slab oneway slabs are those slabs with an aspect ratio in plan of 2. Analysis and design of slabs one way civil engineers pk. 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. The program covers wide range of twoway slab systems and can be used for more complex slab layouts. 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. Twoway slabs have two way bending unlike oneway slab. One way slab is supported by two parallel beams or walls. One way slabs are those supported continuously on the two opposite sides so that the load sare carried along one direction only.
Two way slabs are normally supported from four sides. Design the slab system shown in figure 1 for an intermediate floor where the. The design procedure for a uniformly loaded one way reinforced slab can be divided in the following steps. Aug 15, 2016 download code one way slab design spreadsheet. Design procedure steps for one way slab slab design steps. No redistribution is allowed when method 1 or method 2 of analysis in section 3. 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. Civilax is the knowledge base covering all disciplines in civil engineering.
In concrete slab floors, the draw slab edge tool allows you to draw any shaped edge which is very powerful for a 2 way slab but will break the slab edge rules for one way slabs. Design steps of one way slab rcc free download as pdf file. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types. A typical sixspan, one way slab supported on beams,as occurs in parking structures is selected. For example, when parallel walls connect to either side of a continuous slab, one way action results. Accordingly, main reinforcement is required in the two directions. Reinforced concrete oneway slab design free download as excel spreadsheet. The basic design procedure of a twoway slab system has five steps. In twoway slab, main steel is provided in both span. Two way slab design by direct design method as per aci 31811. Following are the rcc slab design and detailing guidelines. The results of this analysis are compared with the results of the finite element method by sap program.