In many cases the slabs are of such proportions and are supported in such way that twoway action. The ratio of the total costs was found to be within the range 1. The program covers wide range of twoway slab systems and can be used for more complex slab layouts. Best is subjective, so i will give my opinion here. Cornell university, david darwin university of kansas, charles dolan university of wyoming 3. Design of reinforced concrete structures ii two way slabs 1 1. 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. Design of reinforced concrete structures ii twoway slabs. Direct design method, that could have been named the direct analysis method because it determines or prescribes moments for different parts of the slab panel without the need to conduct structural analysis, is explained in the following sections. These materials are originally located at different websites. Twoway concrete floor slab with beams design and detailing design the slab system shown in figure 1 for an intermediate floor where the story height 12 ft, column crosssectional dimensions 18 in.

If, it is below 2 then it is described as two way slab. Design of a structural member is governed by what kind of forces it has to resist. View test prep concrete 3 design of concrete beam and slab twoway slab part 2 2 from engineerin 101 at royal melbourne institute of technology. Two way slabs have two way bending unlike one way slab. The floor, used for a parking garage, was designed using the preexisting architectural drawings of. Twoway slabs are surface members acting in a both directions.

Slab design, bs 8110 slab design, how to determine ultimate load for slabs, how to check for deflection in slabs, how to calculate for dead load, how to calculate for lever arm, basics of slab design, how can i design a 2 way spanning slab. Oneway spanning slabs are supported by two beams or right to the edge of the slab. Unless otherwise noted, all referenced table, figure, and equation. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.

Ultimate load capacity of reinforced concrete slab. Analysis and design of slabs two way civil engineers pk. Team project requiring design and analysis of a steel and reinforced concrete building. Accordingly, main reinforcement is required in the two directions. However, plastic method can be the best method for designing such cases of twoway slabs.

Summary and comparison of twoway slab design results. Design of reinforced concrete structures ii twoway slabs 1 1. Design of a two way rcc slab structural engineering. No certain method can be found in the design codes or references for designing twoway slabs subjected to concentrated loads. This could be for example more concrete or steel reinforcement.

Flat slab analysis, design and detailing pdf civil. Abstractdesigning twoway slabs under transverse concentrated loads is one of the challenges in designing such structures. Two way slab design by direct design method as per aci 31811. Oneway slab design spreadsheet civil engineering community. My graduation project with my mate ghassan faris, a two way ribbed slab of clear span of 18 x 25 m was designed by safe 2014, the building is 3storey concrete. Continuous one way slab figure 1 shows a clear area of 12 m x 8. Civilax is the knowledge base covering all disciplines in civil engineering.

Several residential and office buildings which contain rooms have two way slab. The slab is supported on beams of size 225 x 500 mm spaced at 4. But, with proper application and enough safety factor yield line method. Design of concrete structures 14th edition, 2009, by arthur h. A civil engineer must know all the aspects regarding the flat floor system. A floor slab in a building where stability is provided by shear walls in one direction ns. Flat slab system is an important division of concrete floor system. Oneway spanning slabs should be treated as beams of unit width and chapter 2 should be followed except for minimum shear reinforcement. Two way reinforced concrete slab design spreadsheet working stress design coefficient method download spreadsheet. Twoway flat plate concrete floor system design structurepoint. Master of science and hereby certify that, in their opinion, it is worthy of acceptance. Ec2 webinar autumn 2016 lecture 5 2 designing for shear in slabs when shear reinforcement is not required e. Bridge approach slab analysis and design incorporating elastic soil support presented by.

In a two way slab the slab has to resist the following forces. For a sample output refer to twoway flat plate concrete floor slab design example. In this example deflection will be calculated and checked to satisfy project. This flooring system design is a part of the yearlong masters program at lehigh university. They may be supported on two opposite sides only fig. I have developed a microssoft excel software for design of a two way rcc slab. For example, i n slabcolumn system, which is located in dr y or constantl y wet environment xc1 by ec2, made of concrete c 4050 and with require ment for r ei120, and with unbounded bbrs 20mm. Videos you watch may be added to the tvs watch history and influence tv recommendations. Twoway joist concrete slab floor waffle slab system. Click to share on twitter opens in new window click to share on facebook opens in new window related posts. The imposed loading on the floor is 5 knm2 and an allowance of 2. Flat plate concrete floor system does not use beams between columns or. Ce 433, reinforced concrete design summer 20 example slab design 1 2 material properties geometry compressive strength of concrete fc 5,000 psi span length of slab beam spacing l 18 ft center to center coefficient for depth of stress block 1 0.

In two way slabs shorter direction strip carry greater %age of load. Beams for type 2way slab with beams and type slab with. One way and twoway slabs one way slabs transfer the imposed loads in one direction only. Reinforced concrete design abi aghayere, professor, department of. Reference 5 focused on analysis of twoway ribbed slabs with. Twoway flat plate concrete floor system analysis and design 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. Following are the rcc slab design and detailing guidelines.

Design and detail a typical square spread footing of a six bay by five bay seven story building, founded on stiff soil. These are the direct design method presented in chap. Okay, i know it is based on upper bound thorem and the solution might be unsafe. 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. Concrete 3 design of concrete beam and slab twoway. Analysis of two way ribbed and waffle slabs with hidden beams. The output of the program for the slab in the example is shown in the following pages. The particular design is a twoway posttensioned flat plate. Reinforced concrete slab design and detailing guide is456. The design shear force v d is below the maximum punching strength v rd,max.

Shear force at short span, shear force at long span, where. 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. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. Oneway and twoway slabs university of asia pacific. The lateral loads are independently resisted by shear walls. Reinforced concrete slab design using the empirical. Reinforced concrete design 1 design of slab examples and. Aci 31811 code provides two methods for two way slab design one of which is direct design method. Footings example 1design of a square spread footing of a seven. Twoway concrete slab on beams floor analysis and design. In lieu of detailed calculation for deflections, csa a23.

Uhpc link slab design uhpc workshop june 28th, 2017 jim scarlata, p. Oneway and twoway slabs oneway slabs transfer the imposed. The following example illustrates the example building. Twoway slabs have two way bending unlike oneway slab. Reinforced concrete slab design and detailing guidelines for depth of slab, loads on slab, reinforcement guide for oneway and twoway slabs as per is 456. Slabs are primarily categorized as either one way or two ways. Bending will take place in the two directions in a dishlike form. 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. Detailing of beamcolumn connections, shear walls and twoway slabs. Here, we have tried to gather various reading materials available in the web about flat slab floor system in one place. The design shear force of twoway restrained slab can be calculated as follows. 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 twoway slab. The slab is without drops and is supported internally and on the external long sides by square columns.

A mat foundation is a large concrete slab that supports column or line loads. Plan view of floor system assume partitions will not be damaged by deflections. Aci318 code provides two design procedures for slab systems. Rectangular beams and oneway slabs page 3 of 9 design of rectangular beams and oneway slabs continued a. Dissatisfaction with results of previously required procedures of analysis and design for twoway slabbeam systems was the original reason for the massive research upon twoway slab systems begun about 1955. In our project we adopt design of two way slabs and one way slabs. Department of mechanics, materials and structures english.

The ratio of length to width of one slab should less than 2 otherwise oneway action is obtained, even though supports are provided on all sides. Time saving design aids twoway slabs page 6 of 14 the pca computer program pcaslab can be used to expedite the design of different slab systems. Slab shear strength two way shear check the adequacy of slab thickness for punching shear two way shear at an interior column figure 4. If playback doesnt begin shortly, try restarting your device.

This design example illustrates the empirical design method for composite concrete bridge decks specified in article. Teaching twoway ribbed slab analysis and design using the. In the strength design method, the service loads are increased sufficiently by factors in order to obtain the load at which teaching twoway ribbed slab analysis and design using the mathcad program mohammed s. Chapter 3 design of rectangular beams and oneway slabs. Load transfer in a oneway slab, b twoway slab nilson fig. Firstly, one has to check if the design shear force v d is smaller than the maximum punching strength v rd,max. Design of slab examples and tutorials by sharifah maszura syed mohsin example 2. All available load test results indicated that the flat plate or flat slab was a most efficient design with an adequate safety factor. Point load this problem is designed to demonstrate how to check the ability of a composite slab to carry a 3000 lb point load over an area of 4. Beams of width and depth are provided on all column lines. Two way joist concrete slab floor waffle slab system analysis and design design the concrete floor slab system shown below for an intermediate floor with partition weight of 50 psf, and unfactored live load of 100 psf.

583 393 530 282 305 1274 524 921 324 1452 678 698 395 726 1354 1254 254 307 661 710 1048 885 1418 794 140 1127 87 646 1384 309 1023 1374 616 549 1421 861 622