ppt), PDF File (. In two-way construction, load transfer is by bending in two directions. Demikianlah perbedaan antara One Way Slab (slab satu arah) dan Two Way Slab (Slab dua arah). The requirements for two of them are described in detail in ACI 318-14 Chapter 8 (8. 0uu u u A Tributary kips do O. Design of one way and two way slabs, Design of staircases. Chapter 18 - Concrete Slab Structures January 2019 18-8 18. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. Essential spreadsheet for two way slab design. Two-Way Flat Plate Concrete Floor System Analysis and Design. 8—Slab shear reinforcement. Slabs are usually used in floor and roof construction. Basic Steps in Two-way Slab Design Choose layout and type of slab. The following example illustrates the design methods presented in the PCA book "Simplified Design-Reinforced Concrete Buildings of Moderate Size and Height" third edition. Reinforced Concrete Buildings Series Design Booklet RCB-2. The direct design method is an approximate method used to analyze two way slabs. One way Slab Bending Pattern. 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. How to Design a two-way slab - Free download as Powerpoint Presentation (. If the proportion of longer dimension of the slab panel to the shorter dimension is more than or equivalent to 2 then it is defined as one way slab. Required reinforcement is displayed in a very. Two way Slabs. The direct design method of analysing a two-way slab is not recommended for prestressed slabs. The ACI coefficient method is declared obsolete because the end results are more conservation (more factor of safety). Design conditions set up for the parameter η to determine the yield line pattern 7. Two Way Slab Design Spreadsheets to Eurocode 2 14 March 2018 Off By The Engineering Community Two-way spanning slabs For rectangular slabs with standard edge conditions and subject to uniformly distributed loads, normally the bending moments are obtained using tabulated coefficients. 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 cross-sectional dimensions = 18 in. RCC Slab Design depends on the on the dimensions of the slab after which the slab is termed as a one-way slab or a two-way slab… In the design of RCC structures, Column Design and Beam Design are to be done before we start with RCC Slab Design… Basic Rules followed in the design of simply supported Slab. 0 kN/m2 (excluding slab self-weight) and a variable action of 3. The two-way waffle slab is economical when it is used in the modular or prefabricated form. Inroduction When the ratio (L/S) is less than 2. The yield line theory 6. In two way slab, the ratio of longer span (l) to shorter span (b) is less than 2. com Publisher: allaboutfreebooks. The definition of column and middle. 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. Main reinforcement for two way slabs designs in both directions. 1(a)], in which the structural action is essentially one-way, the loads being carried in direction perpendicular to the supporting beams or walls. In two way slab, the ratio of longer span (l) to shorter span (b) is less than 2. 3 STEP-BY-STEP DESIGN PROCEDURE FOR SLABS Step 1 Analysis Carry out analysis (follow Section 3. Reinforced Concrete Design to BS8110 Structural Design 1 - Lesson 5 6 4. Analysis two way slabs are not direct as in one way slabs. ; A Middle strip is a design strip bounded by two column. Note: One-way spanning slabs should be treated as beams of unit width and Chapter 2 should be followed except for minimum shear reinforcement. While the bending moments and shear forces are computed from the. Chapter 3: Analysis and Design of Two-way Slabs Page 1 CHAPTER 3. Steel will be more in shorter direction. 2, two-way slabs are designed based on "column strips" and "middle strips". Composite beams can only be designed on One Way Slab floor. Type of slab is strongly affected by architectural and construction considerations. Because there are joists in both directions, this floor system is the strongest and will have the least deflection. The specified design strength of the concrete, is 25 MPa () and the specified yield strength of the reinforcement, fy , is 400 MPa. RCC Slab Design depends on the on the dimensions of the slab after which the slab is termed as a one-way slab or a two-way slab… In the design of RCC structures, Column Design and Beam Design are to be done before we start with RCC Slab Design… Basic Rules followed in the design of simply supported Slab. 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. Contains all design checks required by the american concrete institute code and all the conditions that must be met during the design process. Bending will take place in the two directions in a dish-like form. 0uu u u A Tributary kips do O. This spreadsheet is an extremely efficient tool and allows to quickly design two way slabs to aci code. Two way slab being supported on four sides the load will be carried in both the directions. In two way slab design, seems we are designing for the same load for two load paths (two directions), 100% of the load each way. Per ACI 318 13. In above figure (b) represents one way slab. com Slab is a broad and flat structural member mainly used on modern building. Direct Design Method alias DDM as well as Coefficient Method are used to design the slabs. Two-Way Restrained Slab • If the slabs consist more than one panel or corner of the slab are prevent against lifting it is define as two-way restrained slab. Two- way slab systems: Class U with ft ≤ 6√f'c (0. Finite element method. system reported herein is small, since the one-way system is small. The direct design method of analysing a two-way slab is not recommended for prestressed slabs. 5√f'c) as its default value for two-way systems and 7. Corners of the two-way slab lift up if the slab is not cast monolithically with the supports (walls/beams). The two-way waffle slab is economical when it is used in the modular or prefabricated form. Analysis and Design of Two Way Slab: Design Steps: Step 1: Preliminary Design. Slab Dimension. "One Way SLab is a Set of Rectangular Beams Side by Side". PT beams and slabs have an inherent advantage over non-PT members when it comes to deflection. 0, slab is called two-way slab, as shown in the fig. Two edge supported slab is always one-way. Slabs and Flat Slabs Lecture 5 19 th October 2016 usually one and two-way spanning slabs • Punching shear -e. Finite element method. 5 it behaves as one-way slab. A flat slab is a one-way or two-way system with thickenings in the slab at the columns and load bearing walls called 'drop panels' Figure 9. The following example illustrates the design methods presented in the PCA book "Simplified Design-Reinforced Concrete Buildings of Moderate Size and Height" third edition. Two-way slabs subjected mostly to uniformly distributed loads resist them primarily by bending about both the axis. Two-way slab action is assumed in a ribbed floor made of the double-tee section (precast), in the ribbed floor with integral beams. Rectangular Beams and One-way Slabs Page 2 of 9 Two Methods: 1. forced concrete slab resting on four floor steel beams, which in turn are supported by two steel girders. This is a part of his project 'Economic design of two way RCC slabs' under Prof S. 0 Comment for "One-way and two-way slab Design" GO. #Two-way Slab Design Excel #ACI318-08. In two way slabs, load will be carried in both the directions. Composite beams can only be designed on One Way Slab floor. In two-way construction, load transfer is by bending in two directions. Concrete Column design with Two-Way Slabs. Rectangular Beams and One-way Slabs Page 2 of 9 Two Methods: 1. The length and width of slab is much higher than that of its thickness. These slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs or other types of structures. Analysis and Design of Slabs Two Way. Two Way Slab. 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. CHECKS ON SLABS. Two way slab 1. No rebar design will be done. Oct 23, 2019 - Two way slab design Spreadsheet This spreadsheet performs an analysis and design of two-way spanning reinforced concrete slab. Analysis and Design of Two Way Slab: Design Steps: Step 1: Preliminary Design. Design Of Reinforced Concrete Structures ii Two-Way Slabs 1 1. (b) A flat slab which is the same as a flat plate except the areas around the columns have. to highly economic slabs when used in design. There are multiple analysis methods, manual and computer analysis, available for analyzing two-way slabs. The design uses the program ADAPT Floor Pro release 2009/2010 featuring the Hong Kong Code. In two-way slabs, the load will be carried in both directions, thus main reinforcement is provided in both directions for two-way slabs. to highly economic slabs when used in design. These are the Direct Design Method presented in Chap. In above figure (b) represents one way slab. The 2012 edition of the Reinforced Concrete Design Manual [SP-17(11)] was developed in accordance. Longer span (l)/Shorter span (b) ≥ 2. submitted to the faculty of the SCHOOL OF MINES AND M ETALLURGY OF THE UNIVERSITY OF MISSOURI in partial fulfillment of the work required fo r t h e Degree of MASTER OF SCIENCE IN CIVIL E N G I N E E R I N G Rolla, Missouri Approved by. Slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs, bridges, and other types of structures. When a slab's length is more than twice it's width (l > 2w) then the slab can be considered a one-way slab. txt) or view presentation slides online. 0, slab is called two-way slab, as shown in the fig. Another key consideration for reliably predicting the shear capacity of two-way slabs is the so-called size effect. CE 403, Fall 2015 Slab Design Example 1 / 5 (ACI 318‐11 Referenced) Design a one‐way slab for an interior bay of a multi‐story office building using the information specified below. Reinforced Concrete Design to BS8110 Structural Design 1 - Lesson 5 6 4. Share this: Click to share on Twitter (Opens in new window) Click to share on Facebook (Opens in new window) Related posts. CE 403, Fall 2013 One-Way Slab Design 3 / 4 (ACI 318-11 Referenced pp 2 - 4) rating. Materials used for this redesign is normal weight concrete with compressive strength of 4ksi and steel rebar with a yield stress of 60 ksi. Every engineering design needs to follow some basic rules for the completion of most conservative and efficient designs. Effective depth d= Span /((L/d)Basic x modification factor) For obtaining modification factor, the percentage of steel for slab can be assumed from 0. • The design bending moment of two-way restrained slab can be calculated as follows; Moment at short. flat slabs and pad foundations α = angle between the shear reinforcement and the plane of slab fywd,ef = effective design strength of the punching shear reinforcement,. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near mid-span. CHAPTER 7—DESIGN OF SLAB-COLUMN FRAMES UNDER LATERAL. The design load combinations are as follows. 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. One Way Slab Direction. One way slab is a slab that rests on the beam or wall of two opposite sides and carried the load from the same direction. Concrete Column design with Two-Way Slabs. ADAPT uses 6√f'c(0. In this video deisgn of two way slabs has been covered using IS 456. Effective depth d= Span / ( (L/d)Basic x modification factor) For obtaining modification factor, the percentage of steel for slab can be assumed. Rectangular Beams and One-way Slabs Page 2 of 9 Two Methods: 1. Select an item on the right to compare relative dimensions to Two-Way Concrete Flat Slab. ACI 318 - 11: Minimum Thickness of beams and one-way slabs Values given in this table shall be used directly on members with normalweight concrete and Grade 60 reinforcement. Comparison of Concrete Two-Way Slab Analysis and Design Methods A slab system can be analyzed and designed by any procedure satisfying equilibrium and geometric compatibility. Explanatory text was added to each chapter, while maintaining relevant design aids and illustrative examples. The column strip width on each side of the column centerline is equal to 1/4 of the length of the shorter span in the two perpendicular directions. The direct design method of analysing a two-way slab is not recommended for prestressed slabs. Materials used for this redesign is normal weight concrete with compressive strength of 4ksi and steel rebar with a yield stress of 60 ksi. Direct Design Method (DDM) is the preferable method for designing the conventional two way slab system and other floor system like flat slabs and flat plate slab system. Slabs can be designed by Direct Design Method known as DDM and another method for design is Coefficient Method which is the easier one. 1-2 Approximate Bending Moments and Shear Forces for Continuous Beams and One-way Slabs Design Aid J. com Slab is a broad and flat structural member mainly used on modern building. If the ratio of longer span to shorter span is equal or greater then two, the slab is considered as a one-way slab. Rectangular Beams and One-way Slabs Page 2 of 9 Two Methods: 1. For those who do not know what are the des ign requirements of a slab. A 2 2Area 2 A' c 2 2 Post-Tensioned Concrete Design Table 1-1 List of Symbols Used in the ACI 318-08 Code cp Area enclosed by the outside perimeter of the section, in A g Gross area of concrete, in A 2 l Total area of longitudinal reinforcement to resist torsion, in A o Area enclosed by the shear flow path, sq-in A oh Area enclosed by the centerline of the outermost closed. Two-way concrete slabs with openings the static system and the design of reinforcement. Worksheets marked with use PTC Mathcad premium features, otherwise they are Express compatible. In flat-plate floors, slab-column connections are subjected to high shear stresses produced by the transfer of axial loads and bending moments between slab and columns. This section will explain how the direct design method is used. Neglect compression reinforcement. Another key consideration for reliably predicting the shear capacity of two-way slabs is the so-called size effect. Two-way slabs are rectangular reinforced-concrete slabs that are supported on all sides. TWO-WAY SLAB DESIGN. One-way slabs:. The concrete floor slab system shown below is for an intermediate floor to be designed considering partition weight = 20 psf, and unfactored live load = 40 psf. m 88BB ll M wl M wl. Hence, one way slabs have ratio between longer to shorter span greater than 2. The following sketches show the plan of various cases of two-way slabs. ) Finally, since shear reinforcement is not used in one-way slabs, the concrete must be able to resist the maximum shear force. Two Way Slab Reinforcement Details. Strength Design or Ultimate-strength design (USD) Strength Design or Ultimate-strength design (USD) With strength design method, the working dead load (DL) and live load (LL) are. The slab is designed as two way When the ratio of long span to short span is less than 2, then the slab is known as a slab spanning in two directions or two-way slab. For the Direct Design Method moments are found using a simplified. Design of a two way slabs for punching shear resistance. This types of slabs are mostly used in the floor of. com Publisher: allaboutfreebooks. CHAPTER 7—DESIGN OF SLAB-COLUMN FRAMES UNDER LATERAL. The slab may be supported by walls, by reinforced concrete beams usually cast monolithically with the slab, by s. system reported herein is small, since the one-way system is small. 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. Because there are joists in both directions, this floor system is the strongest and will have the least deflection. One Way Slab Design. Structural Redesign Two way slab / Drop panels My redesign of Fordham Place will comprise of a 9" flat slab with 5 ½" drop panels. Effective depth d= Span / ( (L/d)Basic x modification factor) For obtaining modification factor, the percentage of steel for slab can be assumed. 13-July-19. The specified design strength of the concrete, is 25 MPa and the specified yield strength of the reinforcement, fy , is 400 MPa. One way slab is normally designed for gravity load only. The two-way slab will deflect in a dish or saucer-like form under the action of loads. Before going to this topic, Please read it. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. Required reinforcement is displayed in a very. Concrete Slab Design - Two Way Slab Direct Design Method. To see their result for this slab we will find the load factor, λ, to cause failure. Hence, one way slabs have ratio between longer to shorter span greater than 2. If the length to breadth ratio of the room is less than 2, the slab is designed as a two-way reinforced slab. The slab may be supported by walls, by reinforced concrete beams usually cast monolithically with the slab, by s. it may be supported by reinforced concrete beams, by masonry wall or directly by column. Cornell University, David Darwin (University of Kansas), Charles Dolan (University of Wyoming) 3. However, as in the one-way slab, the depth of the two-way slabs should also be checked for the shear stresses to avoid any reinforcement for shear. In two way slab, the ratio of longer span (l) to shorter span (b) is less than 2. The design of two-way slabs based on the direct design method and the equivalent frame method in accordance with the ACI318-05 design code is limited for slabs with beams in column lines only. They increase the shear capacity and the stiffness of the floor system under vertical loads, thus increasing the economical span range. Two Way Slab. In general, if the load from the slab is delivered to the beams in one direction, then the system is one-way. The spreadsheet takes user input values for the slab design parameters such as dimensions and concrete strength, and inputs for the design moments and shear forces. 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. The two-way waffle slab is provided with a bigger span as compared to the solid slab. In above figure (b) represents one way slab. 1): Minimum of three continuous spans in each direction Successive span lengths centre ‐ to ‐ centre of supports in each direction shall not differ by more than one ‐ third of the longer span All loads shall be due to gravityonly and uniformly distributed over an entire panel The. This slab will have significant bending acting in both directions. Dead Load Moments w DL = (125 psf) (25 ft) / 1000 = 3. "What is the difference between one-way slab and two-way slabs?" This is a very basic question for every civil engineer at their beginning stage of civil engineering. Static analysis of two-way slabs, subjected to uniform load, is performed using tables, which give the fundamental support moments, span moments and shear forces. Two way Slabs. The specified design strength of the concrete, is 25 MPa () and the specified yield strength of the reinforcement, fy , is 400 MPa. "One Way SLab is a Set of Rectangular Beams Side by Side". I am third year student persuing B. Neglect compression reinforcement. The two classifications are one-way slab and two-way slab. Section 11. 1): Minimum of three continuous spans in each direction Successive span lengths centre ‐ to ‐ centre of supports in each direction shall not differ by more than one ‐ third of the longer span All loads shall be due to gravityonly and uniformly distributed over an entire panel The. Accordingly, main reinforcement is required in the two directions. Direct design method Simplified method of analysis for regular two ‐ way slab systems Limitations (Cl. Direct Design Method (DDM) is the preferable method for designing the conventional two way slab system and other floor system like flat slabs and flat plate slab system. E-Books RC Design Road Design CAD Blocks SketchUp Construction Mathematics Programming Reinforced Concrete Foundation AutoCAD Books Software Building Specifications Prestressed Concrete Specification Tutorials CutOut Structural Steel Etabs Excel Excel Sheets Information technology Other. 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. Thickness of slab. 5, IS:456 - 2000. Two way slabs are such slabs in which the loads are shared by both the shorter and longer direction of the slab. Unless otherwise noted, all referenced table, figure, and equation. ADAPT uses 6√f'c(0. This spreadsheet performs an analysis and design of two-way spanning reinforced concrete slab. nice user-friendly interface 2. Program does not handle Class C type. Essential spreadsheet for two way slab design. Choose slab thickness that should be adequate for avoiding excessive deflections Choose design method (direct design method in this case). Post-tensioning may be included in both slabs and beams to balance a percentage of the self-weight. 8 CHAPTER 8: DESIGN OF ONE-WAY SLABS 8. INTRODUCTION In reinforced concrete construction, slabs are used to provide flat, useful surfaces. nice user-friendly interface 2. The spreadsheet takes user input values for the slab design parameters such as dimensions and concrete strength, and inputs for the design moments and shear forces. Analysis and Design of Two Way Slab: Design Steps: Step 1: Preliminary Design. 5 it behaves as one-way 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. Hence, one way slabs have ratio between longer to shorter span greater than 2. Worksheets marked with use PTC Mathcad premium features, otherwise they are Express compatible. Design Of Reinforced Concrete Structures ii Two-Way Slabs 1 1. Waffle Slab (Two-Way Pan Joist) Two-way joist slab, also called a waffle slab. Longer span (l)/Shorter span (b) ≥ 2. Contoh penerapan Two Way Slab : Jenis pelat ini digunakan dalam membangun lantai gedung bertingkat dimana terdapat balok di semua sisi plat lantai. If it is less than two, then the slab. Thickness of slab. Constitution D J LeeCBE BScTech DIC FEng FIStructE FICE Chairman, (until April 1995) (previously G Maunsell & Partners) R S Narayanan BE(Hons) MSc DIC FEng FIStructE Chairman, (from May 1995) (S B Tietz & Partners) ProfessorAWBeebyBSc(Eng) PhD CEng MIStructE MICE (University of Leeds) PG CobbCEng MICE (Sir Robert McAlpine & Sons Ltd). Section 11. The Dimensions of an interior bay are shown in Figure 1. e Longer span (l)/Shorter span (b) < 2. essentially the same way as equilibrium is enforced in a truss (Figure 2). In two way slabs, load will be carried in both the directions. Two-Way Slab Design Static Equilibrium of Two-Way Slabs Total Moment in both beams Full load was transferred east-west by the planks and then was transferred north-south by the beams; The same is true for a two-way slab or any other floor system where: 2 2 1 kN. Design the slab, following the provisions of the ACK Code. In two way slab design, seems we are designing for the same load for two load paths (two directions), 100% of the load each way. One way slab is a slab that rests on the beam or wall of two opposite sides and carried the load from the same direction. A review of the design values suggests that a more balanced design option for the subject matter floor slab would be to increase the amount of post-tensioning provided. 1 and rating requirements as stated in 17. Direct Design Method (DDM) is the preferable method for designing the conventional two way slab system and other floor system like flat slabs and flat plate slab system. DOCUMENT DETAILS Publication Year: 2015 Pages: 31 ISBN: Formats: PDF TABLE OF CONTENTS Design Aid J. 4-Two-way Slab with the Hollow Block. Slab design is comparatively easy when compared with the design of other elements. While there is a dearth of published research available describing the behavior of two-way slabs with bonded tendons, the author has received. There are mainly three types of designs for Two-way slab. Member Design - Reinforced Concrete Two Way Spanning Slab BS8110 v2015. Because there are joists in both directions, this floor system is the strongest and will have the least deflection. All worksheets created in PTC Mathcad Prime 2. FOREWORD The Reinforced Concrete Design Manual [SP-17(11)] is intended to provide guidance and assistance to professionals engaged in the design of cast-in-place reinforced concrete structures. The two classifications are one-way slab and two-way slab. (a) A flat plate which is a two-way slab supported on a column grid without the use of beams. Note: One-way spanning slabs should be treated as beams of unit width and Chapter 2 should be followed except for minimum shear reinforcement. 0 kN/m2 (excluding slab self-weight) and a variable action of 3. Program does not handle Class C type. when a gap is maintained between the deck slab and the cross­beam, the slab may be designed as one way slab. Finite element method. There are two types of slab classification based on the direction of bending occurs in these slabs. In two-way slabs shorter direction strip carry greater %age of load. a concrete slab is the plane element having the depth D much smaller than its span and width. Generally, there are two types of slab which are one way and two way slabs. 5, the deflection specifications for two-way slabs. ACI 318-99. In two way slab, the ratio of longer span (l) to shorter span (b) is less than 2. input cells automatically cross out invalid data 3. 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 cross-sectional dimensions = 18 in. Analysis and Design of Slabs. For lower loads they can have constant. Excel sheets are often very useful to determine the slab thickness and reinforcement detailing. (a)Two-way Solid Slab with beams (b)Two-way Waffle Slab with beams (c)Two-way Waffle Slab with integral beams other slabs like two-way slab with the hollow block, waffle slab (with joist beams) made of the precast double-tee section, waffle floor with hollow-block or hollow-cored slabs, Two-way flat plates slab, Two-way flat slabs, and. Methods of analysis of two-way slabs 3. [email protected] Here the ratio of longer span of slab to the shorter span of slab is less or equals to 2. Inroduction When the ratio (L/S) is less than 2. 1-3 Variation of φ with Net Tensile Strain in Extreme Tension Steel εt and c / dt - Grade 60. Traditionally, the term "flat slab" has represented a solid uniform depth slab with thicker drop panels supported upon "mushroom head" conical capitals with round columns or various prismatic brackets with square columns. Two-way Slab Design $ 19. You will design the slab based on the last digit of your id number, for example: 12J123456 will design Slab 6 (X) and if the last digit is zero then can consider Slab 1. The ratio (L/B) which is less than 2 is known as two way slab. 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. There are two types of slab classification based on the direction of bending occurs in these slabs. Books Name: Two Way Slab Design Excel Sheet Author/Writer: allaboutfreebooks. However, the complexity of the generalized approach,. Its made of concrete. Design of a two way slabs for punching shear resistance. There are two types of slab classification based on the direction of bending occurs in these slabs. 1 allows other methods if they meet certain requirements. 20 TWO-WAY SLABS Service (final) stresses Tension stress as multiple of (f'c)^1/2. The slab has to carry a distributed permanent action of 1. 0 International " Version History Cite this work. Two-way Slab Design $ 19. ACI 318-99. Chajjas and verandahs are a practical example of one way slab. 5, the deflection specifications for two-way slabs. Calculate positive and negative moments in the slab. Two-Way Slab Design Static Equilibrium of Two-Way Slabs Total Moment in both beams Full load was transferred east-west by the planks and then was transferred north-south by the beams; The same is true for a two-way slab or any other floor system where: 2 2 1 kN. For lower loads they can have constant. Main features of the spreadsheet 1. Two-Way Flat Plate Concrete Floor System Analysis and Design. 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. BEHAVIOR OF TWO WAY SLABS A rectangular slab supported on four edge supports, which bends in two orthogonal directions and deflects in the form of dish or a saucer is called two way slabs. , interior beam dimensions = 14 in. Civil Engineering 7,527 views. So, main reinforcement is provided in both direction for two way slabs. For example, the minimum slab thickness for a two-hour fire rating is 4. The ratio of the total costs was found to be within the range (1. Bending will take place in the two directions in a dish-like form. com If you like videos help creator (Google UPI. The one-way slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. Main features of the spreadsheet 1. 12) and the cost ratio decreases as the span length increases. A flat slab is a one-way or two-way system with thickenings in the slab at the columns and load bearing walls called 'drop panels' Figure 9. Three established methods are widely used. However, the complexity of the generalized approach,. The two-way slab will deflect in a dish or saucer-like form under the action of loads. Download Free Excel Spreadsheet For Concrete Design of Two Way Slab, Voided Biaxial Slab, Anchorage to Concrete, Anchorage to Pedestal, Circular Column, Concrete Column, Super Composite Column, Special Shear Wall - CBC, Ordinary Shear Wall,Concrete Pool, Corbel, Coupling Beam,Deep Beam, Concrete Development & Splice, Equipment Mounting, Existing Shear Wall, Friction,Pipe Concrete Column, PT. (a) A flat plate which is a two-way slab supported on a column grid without the use of beams. This can be used in conjunction with a structural analysis program such as our Slab Analysis Tool. A two way slab has the main load carried in both directions. When the ratio between the long to short side doesn't exceed 2, a two-way slab is present. two-way slab systems where the structure is modeled by a series of equivalent frames (interior and exterior) on column lines taken longitudinally and transversely through the building. Two way slab 1. The direct design method of analysing a two-way slab is not recommended for prestressed slabs. it may be supported by reinforced concrete beams, by masonry wall or directly by column. Equivalent frame method. 1 Design and Rating Requirements All new concrete slab structures are to meet design requirements as stated in 17. 2: Behavior of Two way slab. Seismic loads will be considered acting in the horizontal direction (along either of the two. The shear capacity of two-way slabs decreases. Design Procedure for One Way Slab. Note: One-way spanning slabs should be treated as beams of unit width and Chapter 2 should be followed except for minimum shear reinforcement. Section 11. I am third year student persuing B. In two way slab, the ratio of longer span (l) to shorter span (b) is less than 2. 101,234 at University of Duhok. The two-way slab is designed for both the directions as it bends in both directions. input cells automatically cross out invalid data 3. 3 Limit States Design Method 18. All worksheets created in PTC Mathcad Prime 2. Reinforced Concrete Buildings Series Design Booklet RCB-2. Analysis two way slabs are not direct as in one way slabs. automatic generation of a step by step design calculation. They may be supported on two opposite sides only [Fig. Therefore a deflection. Concrete slabs are commonly divided into the following types: • Beamless slabs Beamless slabs are supported only on columns and are applied mostly in large industrial and public buildings. A combination of these values will determine the slab stresses at the time of stressing and at service loads. The unit weight of reinforced concrete is assumed to be 24 kN/m3. 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. Module-III Design of short and long columns with axial and eccentric loading, design of isolated column footing. Difference Between One Way Slab & Two way slab. Thickness of slab. One Way Slab Design. Semoga artikel ini bermanfaat dan dapat menambah wawasan dalam bidang struktur. in Civil Engineering in IIT Bhubaneswar. Strength Design or Ultimate-strength design (USD) Strength Design or Ultimate-strength design (USD) With strength design method, the working dead load (DL) and live load (LL) are. I know that there is AASHTO for deck design using one axle or point loads, but these point loads a are smaller. system reported herein is small, since the one-way system is small. There are mainly three types of designs for Two-way slab. The One-Way model behavior is very different than Two-Way slab, see One-Way Slab Design for more information. Design of slabs,beams,columns,etc. ppt), PDF File (. In addition, A23. Interior Bay Dimensions 20' 24' This example is to be used for educational purposes only. The slab may be supported by walls, by reinforced concrete beams usually cast monolithically with the slab, by s. In Ram Concrete, the column K factor is determined based on the relative stiffness of the beams to the columns. Two-way slabs have two way bending unlike one-way slab. 4-Two-way Slab with the Hollow Block. Procedures of Two Way Slab Design by Direct Design Method Determine slab type and layout. Figure 3 shows the effect of increasing the slab effective depth on the normalized punching capacity (4V test / V ACI) for selected test results extracted from the ACI 445 Punching Shear Test Databank (Ospina et al. There are no reviews yet. 0, slab is called two-way slab, as shown in the fig. Brendon Burley Structural Option Post-Tensioned Two-Way Slab Figure 2-3 Details of the two-way slab: Interior (left), Exterior (right) Deflection Analysis The final consideration in the design of the two-way slabs is deflection. Cantilever slab is always one-way. The two-way waffle slab is economical when it is used in the modular or prefabricated form. Slabs can be designed by Direct Design Method known as DDM and another method for design is Coefficient Method which is the easier one. Notes on One Way Slab Design -Dr. The direct design method of analysing a two-way slab is not recommended for prestressed slabs. TIME SAVING DESIGN AIDS 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: Two-way Slabs," by David A. Design of Two-way Slabs: Slabs are defined as two-way slabs when the ratio of long-to-short sides is less than 2. Rectangular Beams and One-way Slabs Page 2 of 9 Two Methods: 1. But in one way slab design, we are desigining for one load path for the area distributed load. 4- Limit state design 5- Yield line (plastic) ACI- Code 1963 –Coefficient method (3): The slab was divided into strips (middle and column or edge strip) with the diemension as shown in figure below:. A reinforced concrete slab is a broad, flat plate, usually horizontal, with top and bottom surfaces parallel or nearly so. Two Way Slab Design Spreadsheets to Eurocode 2 14 March 2018 Off By The Engineering Community Two-way spanning slabs For rectangular slabs with standard edge conditions and subject to uniformly distributed loads, normally the bending moments are obtained using tabulated coefficients. Difference between One way Slab & Two way Slab - Duration: 8:23. Step 2 Design forces Draw panel of slab and indicate maximum design moments, shears and in-. This slab will have significant bending acting in both directions. • This condition occur when the slabs are connected monolithically with support. One Way slabs will not create a plate submeshed floor "slab" like the Two Way slab. A reinforced concrete slab is built integrally with its supports and consists of two equal spans, each with a clear span of 15 ft. Every example I've ever seen on two-way slab design is for uniformly distributed loads. Calculate positive and negative moments in the slab. Two-way slab action is assumed in a ribbed floor made of the double-tee section (precast), in the ribbed floor with integral beams. The analytical solution can be applied easily for design of slabs. Such coefficients are provided later in this section. Two way slabs are such slabs in which the loads are shared by both the shorter and longer direction of the slab. 1 Design and Rating Requirements All new concrete slab structures are to meet design requirements as stated in 17. Detailing drawing of slab is also explained. Flat Slab Floor System. These slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs or other types of structures. com Publisher: allaboutfreebooks. 1—Minimum slab thickness. #Two-way Slab Design Excel #ACI318-08. Two way slabs are normally supported from four sides. A one way slab will only have significant bending moments in the short direction. 0 Comment for "One-way and two-way slab Design" GO. 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. CE 403, Fall 2013 One-Way Slab Design 3 / 4 (ACI 318-11 Referenced pp 2 - 4) rating. In two-way slabs shorter direction strip carry greater %age of load. Dead Load Moments w DL = (125 psf) (25 ft) / 1000 = 3. Design of slabs,beams,columns,etc. CHAPTER 6—SERVICEABILITY CONSIDERATION. In two-way slabs, the load will be carried in both directions, thus main reinforcement is provided in both directions for two-way slabs. A combination of these values will determine the slab stresses at the time of stressing and at service loads. Distribute. Two Way Slab Design Spreadsheets to Eurocode 2 14 March 2018 Off By The Engineering Community Two-way spanning slabs For rectangular slabs with standard edge conditions and subject to uniformly distributed loads, normally the bending moments are obtained using tabulated coefficients. 13-July-19. Thanks for the reponse. It is especially critical where drainage can be an issue in cases such as roofs, parking garages, and balconies, and with flat plates where long term. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. Part 1: Two-way Slabs. The design load combinations are as follows. Design Procedure for One Way Slab. design, behaves in between a rectangular and a flanged section for moment distribution. Two Way Slab: Two-Way Slab Design Based on ACI 318-19 using Finite Element Method: 41: Existing Beam Enhancement: Existing Concrete Beam Enhancement Based on 2015 IEBC, ASCE 41-17 & ACI 318-19: 42: Existing Floor Enhancement: Existing Concrete Floor Enhancement Based on 2015 IEBC, ASCE 41-17 & ACI 318-19: 43: Bearing Wall for ICF. This types of slabs are mostly used in the floor of. (a)Two-way Solid Slab with beams (b)Two-way Waffle Slab with beams (c)Two-way Waffle Slab with integral beams other slabs like two-way slab with the hollow block, waffle slab (with joist beams) made of the precast double-tee section, waffle floor with hollow-block or hollow-cored slabs, Two-way flat plates slab, Two-way flat slabs, and. This defines whether the design is a Two-Way slab design or One-Way slab design. The first Reinforced Concrete Design Manual (formerly titled ACI Design Handbook) was developed in accordance with the design provisions of 1963 ACI 318 Building Code by ACI Committee 340, Design. Difference between One way Slab & Two way Slab - Duration: 8:23. Two Way Reinforced Concrete Slab Design Spreadsheet (Working Stress Design Coefficient Method) Download Spreadsheet. The shear capacity of two-way slabs decreases. In two way slab, the ratio of longer span (l) to shorter span (b) is less than 2. Three established methods are widely used. 4-Two-way Slab with the Hollow Block. e in the direction along its shorter span. Depending on the boundary condition and the properties of the slabs, methods of finding bending moment is expressed in the BS 8110 Part 01 as follows. CHECKS ON SLABS. Section 11. 1(1) Crack Control of Slabs Part 1: AS 3600 Design 7. Rectangular Beams and One-way Slabs Page 2 of 9 Two Methods: 1. For lower loads they can have constant. Cornell University, David Darwin (University of Kansas), Charles Dolan (University of Wyoming) 3. In above figure (b) represents one way slab. It is always necessary to design a safe and load bearing capable slab. when a gap is maintained between the deck slab and the cross­beam, the slab may be designed as one way slab. a concrete slab is the plane element having the depth D much smaller than its span and width. Oct 23, 2019 - Two way slab design Spreadsheet This spreadsheet performs an analysis and design of two-way spanning reinforced concrete slab. A reinforced concrete slab is a broad, flat plate, usually horizontal, with top and bottom surfaces parallel or nearly so. Excel sheets are often very useful to determine the slab thickness and reinforcement detailing. Method #1 - Slab, Wall, Beam, and Column Design within the 2D / 3D model Slabs / Walls: Select the View tab and the Stresses button. If it is less than two, then the slab. txt) or view presentation slides online. Distribute. Allowable stress design or working stress design (WSD) 2. View Design of two-way slabs(D. 2 Design Data Column. This slab will have significant bending acting in both directions. This is a part of his project 'Economic design of two way RCC slabs' under Prof S. This spreadsheet performs an analysis and design of two-way spanning reinforced concrete slab. The ratio (L/B) which is less than 2 is known as two way slab. automatic generation of a step by step design calculation. Inroduction When the ratio (L/S) is less than 2. Member Design - Reinforced Concrete Two Way Spanning Slab BS8110 v2015. ANALYSIS AND DESIGN OF TWO-WAY SLABS 3. The equivalent frame consists of three parts: 1) Horizontal slab-beam strip, including any beams spanning in the direction of the frame. One way Slab Bending Pattern. Post-tensioning may be included in both slabs and beams to balance a percentage of the self-weight. The basic design procedure of a two-way slab system has five steps. nice user-friendly interface 2. There are three cases to look at for shear. One-way and Two-way Slabs One-way slabs transfer the imposed loads in one direction only. The two-way waffle slab is economical when it is used in the modular or prefabricated form. Slabs and Flat Slabs Lecture 5 19 th October 2016 usually one and two-way spanning slabs • Punching shear -e. A one-way reinforced slab may be stronger than a two-way non-reinforced slab, depending on the type of load. Unless otherwise noted, all referenced table, figure, and equation. Search This Blog Slab design Example 02 Design of simply supported slab (Two way spanning) Span of slab 4. The first stage of the design is finding the bending moment of the slab panels. It is especially critical where drainage can be an issue in cases such as roofs, parking garages, and balconies, and with flat plates where long term. Corners of the two-way slab lift up if the slab is not cast monolithically with the supports (walls/beams). 28 Design Example 1. 0 International " Version History Cite this work. Two-way slabs are also pr esent as mat (raft) foundation. • The design bending moment of two-way restrained slab can be calculated as follows; Moment at short. The analytical solution can be applied easily for design of slabs. Thanks for the reponse. Size Effect. Oct 23, 2019 - Two way slab design Spreadsheet This spreadsheet performs an analysis and design of two-way spanning reinforced concrete slab. Rectangular Beams and One-way Slabs Page 2 of 9 Two Methods: 1. ppt), PDF File (. How to Design a two-way slab - Free download as Powerpoint Presentation (. 62√f'c) as default for one- way systems. Slabs or foundations can be of any shape, and can include edges shaped with circular and spline curves. 75 2 (18 14) ( ) 248. Comparison of Concrete Two-Way Slab Analysis and Design Methods A slab system can be analyzed and designed by any procedure satisfying equilibrium and geometric compatibility. One way slab is supported by two parallel beams or walls; Two way slab is supported by four sides. The One-Way model behavior is very different than Two-Way slab, see One-Way Slab Design for more information. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near mid-span. The specified design strength of the concrete, is 25 MPa () and the specified yield strength of the reinforcement, fy , is 400 MPa. Slabs having supports on less than four sides can be designed as one-way. Early codes distinguished between four-way reinforcement and two-way reinforcement systems. Practical Yield Line Design 2 Notation Symbols The symbols used in this publication have the following meaning: Symbol Description Units A Area of column cross-section m2 a, b, c Plan dimensions of slab supported on several sides m. #N#Anchored Bulkheads. The design of two-way slabs based on the direct design method and the equivalent frame method in accordance with the ACI318-05 design code is limited for slabs with beams in column lines only. Send Question. Note: One-way spanning slabs should be treated as beams of unit width and Chapter 2 should be followed except for minimum shear reinforcement. A waffle slab or two-way joist slab is a concrete slab made of reinforced concrete with concrete ribs running in two directions on its underside. 1-2 Approximate Bending Moments and Shear Forces for Continuous Beams and One-way Slabs Design Aid J. I have developed a Microssoft Excel Software for Design of a Two Way RCC Slab. Referensi :. Load transferring mechanism is one of the key features that should have a high attention in designing. Two Way Slab Reinforcement Details. Unless otherwise noted, all referenced table, figure, and equation. To determine if the slab is two way, figure the ratio between the longer span and the shorter span. The main supports are found going in both directions. Its made of concrete. Two Way Slab. One way slab is a slab which is supported by beams on the two opposite sides to carry the load along one direction. Hence, one way slabs have ratio between longer to shorter span greater than 2. 12) and the cost ratio decreases as the span length increases. Slabs are primarily categorized as either one way or two ways. m BB 8 l M wl 22 12 A-A 2 1 kN-m, kN. 1(1) Crack Control of Slabs Part 1: AS 3600 Design 7. For a concrete shell element, you may select AS1 or AS3 from the drop down menu to see a color-coded output of required area of flexural reinforcement in each of the principal directions, both top and bottom. Two way slab design by direct design method as per ACI 318-11, step by step procedure and limitations of direct design method for two way slab is presented. Choose layout and type of slab. The calculation of One Way Slab Reinforcement Details Design is extremely tedious and time-consuming and after give more time is not 100% sure that design is best or not and also if some minor change comes in design if force to calculate. Two way slabs are normally supported from four sides. The yield line theory 6. Module-III Design of short and long columns with axial and eccentric loading, design of isolated column footing. Suspended slabs can include flat, two-way, waffle, and ribbed framing systems. Download Two way Slab Design Excel Sheet Template. L/B>2 is one way slab L/B<2 is two way slab. Site will guide you, the way to follow when designing to eurocode 2. 1-2 Approximate Bending Moments and Shear Forces for Continuous Beams and One-way Slabs Design Aid J. However, two-way slabs with bonded tendons are widely used in other parts of the world—notably, Asia, Europe, and Australia. Cantilever slab is always one-way. RCC Slab Design is a free app for designing one way and two way reinforced concrete slab systems as per Indian Standards.