One way and two-way slab pdf

Reinforced concrete slab slabs are plate elements forming floors, roofs in buildings. Generally, there are two types of slab which are one way and two way slabs. Most of residential and office buildings have rooms that have two way slab. The load on the one way slab is carried by the short span in one direction. Two way slab analysis and design using equivalent frame method efm aci 318 states that a slab system shall be designed by any procedure satisfying equilibrium and geometric compatibility, provided that strength and serviceability criteria are satisfied. Oneway and twoway slabs oneway slabs transfer the imposed. Pdf shear in oneway slabs under concentrated load close. So how do you differentiate a oneway and twoway slab.

Oneway slab is supported by parallel walls or beams, whose length to breadth ratio is equal to or greater than two. Deep ribs, the concrete and steel quantities are relative low expensive formwork expected. Rectangular beams and one way slabs page 3 of 9 design of rectangular beams and one way slabs continued a. If slab is supported on all four sides and r shorter side longer side one way slab. Development length, anchorage, splice, deflections and crack control 10. However, sometimes its hard to decide whether the slab is one way or two way by looking into the supports or edges thats why we also. Design of reinforced concrete structures ii two way slabs 1 1.

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. 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. Difference between one way slab and two way slab civil read. Design of reinforced concrete structures ii twoway slabs. Pdf transition from oneway to twoway shear in slabs under. Reinforcement detailing of reinforced concrete slabs. Analysis and design of slabs one way civil engineers pk. 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. Can be used for larger spans with relatively higher cost and higher deflections one way joist system suitable span 6 to 9m with ll 46knm2. Design of one way slabs the structural action of a one way slab may be visualized in terms of the deformed shape of the loaded surface. Rasio bentang yang lebih panjang l ke bentang yang lebih pendek b sama dengan atau lebih besar dari 2, dianggap sebagai plat satu arah karena slab ini akan menekuk dalam satu arah yaitu pada arah sepanjang rentang yang lebih pendek.

Before understanding the one way slab or two way slab, one should understand the slab. The one way slab reinforcement only supports walls in one direction. Define the term slab, one way slab, two way slab, shrinkage and temperature reinforcement, main reinforcement. What is the difference between one way and two way slab. Two way slab being supported on four sides the load will be carried in both the. 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.

If less than 2 then it is designed as a two way slab. Download two way slab design excel sheet template for free. The behavior and the reinforcement of a one way slab connected to a cantilever are described below. In two way slab, the ratio of longer span l to shorter span b is less than 2.

D mm d 105 mm loads on slab self weight of slab 3. 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. The one way slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. Difference between oneway slab and twoway slab gharpedia. Bending will take place in the two directions in a dishlike form. In one way slab main reinforcement is parallel to shorter direction and the reinforcement parallel to longer direction is called distribution steel. So, main reinforcement is provided in both direction for two way slabs. Here the ratio of longer span of slab to the shorter span of slab is less or equals to 2. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types. Due to the huge difference in length, load is not transferred along the longer direction. The various forms and types of the one way systems are tabulated below. 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. Chapter 3 design of rectangular beams and oneway slabs.

Difference between one way slab and two way slab daily civil. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan. Guidelines for a twoway concrete flooring system brewer. Difference between the one way slab and two way slabs are as follows.

Slabs are usually used in floor and roof construction. A one way slab reinforcement supports 2 walls while a two way slab reinforcement supports 4 walls. They may be supported on two opposite sides only fig. Guidelines for a oneway concrete flooring system brewer. In this paper the cost optimization of reinforced concrete two way slabs under uniformly distributed load with the nonlinear programming approach has been presented and it is a continuation of the. The rest of the floor can be slightly thinner with less dead weight. Depending on their load carrying behavior, they are classified as one way slab and two way slab.

Pdf reinforced concrete oneway slabs subjected to concentrated loads are. For those who do not know what are the des ign requirements of a slab. In reinforced concrete construction, the slab is an extensively used structural element forming floors and roofs. There are some basic differences between one way slabs and two way slabs. Slabs having supports on less than four sides can be designed as one way. In practices, the choice of one way slab and two way slab for a particular structure will largely depend upon the economy, build ability, loading conditions and length of the span. Two way slab design by direct design method as per aci 31811. However the main reinforcement bar and distribution bar in a transverse direction. Load transfer in a oneway slab, b twoway slab nilson. To clear the concept of one way and two way slabs a table is shown below. One way slab is a slab which is supported by beams on the two opposite sides to carry the load along one direction. The two classifications are oneway slab and two way slab. Design procedure steps for one way slab slab design steps. Figure 1 shows a rectangular slab, simply supported along its two opposite long edges and free of any support along the two.

Slab shear strength two way shear check the adequacy of slab thickness for punching shear two way shear at an interior column figure 4. The basic design procedure of a two way slab system has five steps. These slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs or other types of structures. In two way slabs, the load will be carried in both directions, thus main reinforcement is provided in both directions for two way slabs. 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 with main reinforcement and the distribution of reinforcement in the transverse direction what is two way slab. Pdf oneway and twoway slabs mohamed tiger academia. Analysis, design and detailing of continuous beams and slabs 9. The slabs are considered as spanning two way when the longer to shorter span length is less than a ratio of two. To be able to better evaluate the shear resistance of one way slabs, a series of experiments was carried out on continuous one way slabs 5 m x 2. 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. Oneway and twoway slabs university of asia pacific. The load on the slab is carried by the short span in one direction.

Design and detailing of one way and two way slabs 8. The slabs having ratio of longer length to its shorter length l y l x greater than 2 is called one way slab otherwise as two way slab. Learning outcomes at the end of this lecture, the student should be able to a classify all types of solid slab co1 b identify one way and two way solid slab co1 c use a relevant clauses in code of practice co1 d design one way slabs co2 e details the slabs co1. Design of nonsway short and long concrete columns 11. Fanella, which appeared in the october 2001 edition of structural engineer magazine. 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 one way slab. One way wide module joist slab in the lower middle is a variation on the one way. If a slab is supported on all the four sides but the ratio of longer span to shorter span is greater than two, the slab will be considered as a one way slab. In two way slabs, load will be carried in both the directions.

Two way slabs are such slabs in which the loads are shared by both the shorter and longer direction of the slab. One way slab design procedure with example design of one. One way slab adalah slab yang didukung oleh balok pada dua sisi yang berlawanan untuk memikul beban sepanjang satu arah. If the first slab is a two way slab, both the behavior and the reinforcement rules are proportionate. A number of code provisions refer to flexural members, which include one and twoway slabs, beams, girders, footings, and, where bending exists with the. Design of two way floor slab system comparison of one way and two way slab behavior one way slabs.

Pdf design calculation design of one way slab slab s1. Unless otherwise noted, all referenced table, figure, and. Here are the steps for the design procedure for one way slab in steps. One way slab design excel sheet civil engineers pk. The following example illustrates the example building. Pdf cost optimum design of reinforced concrete simply.

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. 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. However main reinforcement bar and distribution bar in transverse direction. Oneway and two way slabs one way slabs transfer the imposed loads in one direction only. Distinction of twosystems from one way systems is given by aci 31814 r8.

Experimental study of shear in reinforced concrete oneway. Difference between one way slab and two way slab system. Distribute moments transverse at critical sections to column and middlestrip and if. In two way slab main reinforcement is provided along both. Slabs, beams, columns and foundations are the key segments of buildinghouse which provides strength to remain undisturbed against different loads and offers strength so that it performs well during their service life. One way shear structural engineering general discussion. This system is similar to the two way flat plate system except there is a drop panel to provide extra thickness around the columns. Design and detailing of different types of staircases. Here are the differences between one way slab and two way slab.