Step 2 design forces draw panel of slab and indicate maximum design moments, shears and in plane loads, if any, per unit width of slab. Based on the stiffness requirement assume suitable depth and calculate the effective span. The two classifications are oneway slab and twoway slab. In this example, the latter option will be used to achieve better understanding for the design of twoway joist slab often called twoway ribbed slab or waffle slab. Slab design reading assignment chapter 9 of text and, chapter of aci31802.
The thickness of oneway slab varies between 100mm to 150mm or even more depending upon the span and based on the deflection considerations. In flatplate floors, slab column connections are subjected to high shear stresses produced by the transfer of axial loads and bending moments between slab and columns. There are some basic differences between one way slabs and two way slabs. The proposed slab system must be able to be constructed at a reasonable cost. Difference between one way slab and two way slab slab. Here ratio of longer span of slab to the shorter span of slab is greater than 2. Draw the slab, and lebel all the reinforcement sizes and spacings. Oneway and twoway slabs oneway slabs transfer the imposed. Cant get the attachment to take on the slide show pdf. Difference between one way slab and two way slab simple. In this post, we are going to explain how to calculate steel quantity for the slab. Reinforcement detailing of a slab is done based on its support conditions. Behavior and reinforcement of one way slab the structural frame consists of four columns, two beams and one slab. Sandwich slab reinforcement details in reality, sandwich slabs are ribbed slabs with a slab placed both to their upper and lower surface.
Pdf design calculation design of one way slab slab s1 span. In two way slabs, load will be carried in both the directions. Sep 10, 2017 usually, the two way slab is adopted when the length and width of the slab is more than 4m. The proposed slab system must meet the current code. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems. A oneway 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 in that direction only. Use the equivalent frame method efm and compare the results with spslab model results.
Oct 27, 2016 one way slab is a slab which is supported by beams on the two opposite sides to carry the load along one direction. First, find number of rods required for main reinforcement and distribution. Shear reinforcement using vertical stirrups in integral beams avoids much of this difficulty. The load on the slab is carried by the short span in one direction. Difference between one way slab and two way slab daily civil. A cost analysis will be provided based on data from rs means. Oneway spanning slabs should be treated as beams of unit width and chapter 2 should be followed except for minimum shear reinforcement. For better view, please read this post in landscape mode if you are on the mobile device. However main reinforcement bar and distribution bar. Here are the steps for the design procedure for one way slab in steps. When a concrete slab is supported on all four sides and the ratio of long span to short span is greater or equal or than two, this means its a oneway slab. So, main reinforcement is provided in both direction for two way slabs. Fortunately this is a basic question and the answer is very simple.
Simply supported one way slab a rectangular reinforced concrete slab is simplysupported on two masonry walls 250 mm thick and 3. Oneway and twoway slabs oneway slabs transfer the imposed loads in one direction only. Chapter 3 design of rectangular beams and oneway slabs 12. Twoway concrete slab with beams spanning between supports. One way and two way slabs one way slabs transfer the imposed loads in one direction only. If slab supported by four side of beams or walls, the slab is considered oneway if ratio of long span ly to short span lx greater than 2. Pdf enhancing the behavior of oneway reinforced concrete. Design of slab examples and tutorials by sharifah maszura syed mohsin. The simplest routine structural element for illustration of design provisions in the code is the oneway slab. 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 in that direction only.
Nonprestressed bonded reinforcement in posttensioned. Bending will take place in the two directions in a dishlike form. Determine moments at critical sections in each direction, normally the negative. Pdf behaviour and strength of one way reinforced concrete. D mm d 105 mm loads on slab self weight of slab 3.
One way spanning slabs should be treated as beams of unit width and chapter 2 should be followed except for minimum shear reinforcement. Design procedure steps for one way slab slab design steps. For those who do not know what are the des ign requirements of a slab. In a two way system such as a columnsupported slab, the load is carried in both directions. Sandwich slabs may have the disadvantage of a larger weight compared to the ribbed ones but on the other hand, they have the advantage that their spans and supports behave in the same proper way. Ce 433, summer 20 slab design example 1 5 design a one. The load on the oneway slab is carried by the short span in one direction. One way slab being supported on two opposite sides only leads to the structural action in single direction. Would love to provide these pictures for better clarity of the viewers. One way slab design procedure with example design of one. The ratio lb which is less than 2 is known as two way slab. Chapter 3 design of rectangular beams and oneway slabs. The oneway slab is a simple wide shallow rectangular beam as.
Define the term slab, one way slab, two way slab, shrinkage and temperature reinforcement, main reinforcement. Design of slab examples and tutorials by sharifah maszura syed mohsin example 1. Application of one way slab provides useful flat surface one way slab may be used when there is architectural limitations it is the simplest form of slab design main reinforcement placing is one way, so there is a little congestion than two way slab 29. Apr 16, 2018 fortunately this is a basic question and the answer is very simple. If playback doesnt begin shortly, try restarting your device. Verandah slab is a type of one way slab, where the slab is spanning in the shorter direction with main reinforcement and the distribution of reinforcement in the transverse direction what is two way slab. One way slabs are such slabs in which the loads are shared only by the shorter direction of the slab. Why are we provide main reinforcement in bottoms in a one. Why are we provide main reinforcement in bottoms in a oneway. To provide adequate support on the larger side, the main reinforcement bar is provided perpendicular to that side or parallel to the shorter direction. One way slab reinforcement details daily civil engineering. 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. Feb 24, 2019 continuous oneway solid slab last updated on sun, 24 feb 2019 concrete structures this calculation is intended to show in detail the provisions of designing a slab to eurocode 2 using essentially the same slab as used in example 3. And what does oneway shear reinforcement in slabs look like.
Well to make you perfect in bar bending schedule for a slab, i am considering a one way slab and two way slab as shown in the figure. The codes governing the design of the one way slab will be aci 31802 and ibc 2003. Oneway and two way slabs one way slabs transfer the imposed loads in one direction only. In this article, i will discuss how to design one way slab with example. Slab supported directly by columns are called flat slab. In reality, sandwich slabs are ribbed slabs with a slab placed both to their upper and lower surface. The codes governing the design of the oneway slab will be aci 31802 and ibc 2003. Design of oneway slabs check if it is oneway slab system if clear span in one direction, l1, is greater than or equal to two times the clear span in other direction, l2, then it is.
Behavior and reinforcement of oneway slab the structural frame consists of four columns, two beams and one slab. Two way slabs are the slabs that are supported on four sides and the ratio of longer span l to shorter span b is less than 2. For b oth one way and two way slab with an example. Chapter 3 design of rectangular beams and oneway slabs 12 h. I am doing oneway slabs and hope you can clean up my doubts about the one way shear in slab. Pdf this paper studies experimentally the behavior of laced reinforced concrete oneway slabs under monotonic load.
Reinforced concrete design 1 design of slab examples and. Our friend mohit sharma has already highlighted the essentials for a one way slab. Two way slabs are normally supported from four sides. Experimental and numerical analysis article pdf available in european journal of environmental and civil engineering. A bentup bar called as crank bar is provided to make rcc slab safe from compressive stresses. Reinforced concrete design 1 design of slab examples. Apr 27, 2017 1 a slab is one way slab when a slab is supported on two edges and bends in only one direction. Buildinghow products books volume a the reinforcement. Oneway concrete slab design part 1 concept explained and minimum slab thickness canadian code duration.
Slab are considered as oneway if the main reinforcement is designed only in one direction. 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. Pdf cost optimum design of reinforced concrete simply. They may be supported on two opposite sides only fig.
Design of one way reinforced concrete slabs class notes and example notes on. Posttensioned oneway slab pennsylvania state university. Plan view of floor system assume partitions will not be damaged by deflections. The very purpose of reinforcement in rcc structures is to contain the tensile stresses induced in the system.
These tests demonstrated that adequate, codeconformant behavior in twoway posttensioned slabs fig. Pdf oneway slabs subjected to a combination of loads failing. The oneway slabs are economical up to the span of 3. The thickness of one way slab varies between 100mm to 150mm or even more depending upon the span and based on the deflection considerations. Check the applicable joist dimensional limitations as follows. I like to debate structural engineering theory a lot.
Analysis and design of slabs one way civil engineers pk. For one way slab, main reinforcement is computed by a formula in limit state design that is determined by comparing compressive force as well as tensile forces. Such slabs are designed as oneway slabs where the span length ln is equal to the length of short direction. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types. However the main reinforcement bar and distribution bar in a transverse direction. Figure 1 twoway slab with beams spanning between all supports. A oneway slab is defined for purposes of this book. This condition occur if the slab supported by two side of beam or walls. Shrinkage and temperature reinforcement in twoway post. In some instances, such as corner columns in flat slabs, and strong beamweak column connections at the upper levels of one way slab and beam.
Assume partitions cannot be damaged by deflections. Calculate factored moment and shear force by considering the onemeter width of the slab. For slabs and beams, bending flexure is the criteria and there by t. Pdf evaluation of oneway shear behavior of reinforced. Further discussion of the differences between one and two way systems is given in reference aalami, 1993b.
Slab may be supported on walls or beams or columns. The slab may be supported by walls, by reinforced concret. Further discussion of the differences between one and twoway systems is given in reference aalami, 1993b. The paper presents the cost optimization of reinforced concrete simply supported oneway slabs under uniformly distributed load with the nonlinear programming approach. Jul 02, 2015 one way concrete slab design part 1 concept explained and minimum slab thickness canadian code duration. 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. In one way slab main reinforcement is parallel to shorter direction and the reinforcement parallel to longer direction is called distribution steel. Main bars and distribution bars are provided in the one way slab. Oneway and twoway slabs university of asia pacific. The slab has to carry a distributed permanent action of 1. In flatplate floors, slabcolumn connections are subjected to high shear stresses produced by the transfer of axial loads and bending moments between slab and columns. If slab is supported on all four sides and r shorter side longer side may 02, 2017 one way slab reinforcement details. In this example, the latter option will be used to achieve better understanding for the design of two way joist slab often called two way ribbed slab or waffle slab.
The one way slabs are economical up to the span of 3. The one way slab is a simple wide shallow rectangular beam as far as its structural analysis is concerned. Usually, when a slab is supported by a beam the support is considered to be pinned. In a twoway system such as a columnsupported slab, the load is carried in both directions. Load transfer in a oneway slab, b twoway slab nilson. Evaluation of oneway shear behavior of reinforced concrete slabs. For a detailed discussion of one versus two way systems, refer to aalami. 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.
In one way slab, the ratio of longer span l to shorter span b is equal or greater than 2, i. When a reinforced concrete slab is 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. Reinforcement detailing of reinforced concrete slabs. Slabs are usually used in floor and roof construction. In one way slab, as one side is greater than the other side, the maximum load is carried by the larger side just so giving main reinforcement comparing to that load carrying side will be adequate. This data is good for know the difference between one way slab and two way slab but if u provide to how to reinforcement design in one way and two way slab so its very helpfull. Slab supported on two sides and bending takes place predominantly in one direction only is called one way slab. Twoway joist concrete slab floor waffle slab system. In this study, one directional hollow slabs were experimented to investigate the behavior of the reinforced concrete slab containing cavities. One way slab is supported by two parallel beams or walls. Continuous oneway solid slab concrete structures eurocode. The basic design procedure of a twoway slab system has five steps. Oneway slabs notes edurev notes for is made by best teachers who have written some of the best books of.
Accordingly, main reinforcement is required in the two directions. Verandah slab is a type of one way slab, where the slab is spanning in the shorter direction. As they are oneway slabs i treat them as wide beams. One way shear in slab structural engineering general. Difference between one way slab and two way slab civil read. The paper presents the cost optimization of reinforced concrete simply supported one way slabs under uniformly distributed load with the nonlinear programming approach. Slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs, bridges, and other types of structures. Rectangular beams and oneway slabs page 3 of 9 design of rectangular beams and oneway slabs continued a. In two way slab main reinforcement is provided along both direction.
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