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. Waffle slab design example structural engineering general. Posttensioned concrete design spreadsheet program a pdh. There are various established methods for analysing ribbed slabs and dealing with the solid areas. The best book to refer to is reinforced concrete design to eurocode by bill mosley. Project specific slab designs are created using an optimised combination of prestressed slab beams in conjunction with our infill options. Rtslab simple building construction slab rib software. In many domestic and industrial buildings, a thick concrete slab supported on. This tool provides a excellent economic design of a rcc slab spanning in two directions under loading conditions provided by the user keeping in mind all design considerations prescribed in is 456. They provide a very good form where slab vibration is. Ribbed or waffle slab is a slab system which consists of series of parallel reinforced concrete t beams framing into reinforced concrete girders. Suspended slabs can include flat, twoway, waffle, and ribbed framing systems. Slabs is a program that can be used by structural engineers to perform a static analysis and design of reinforced concrete slab systems of any shape, including suspended slabs and slabsonground.
Ribbed and waffle slabs provide a lighter and stiffer slab than an equivalent flat slab, reducing the extent of foundations. Slabs are usually used in floor and roof construction. Slabs or foundations can be of any shape, and can include edges shaped with circular and spline curves. We aim to close the gap to the industry by improving the awareness about latest trends in civil engineering. Design icon set is a collection of wonderfullycrafted stock icons for use in commercial and personal products, including software applications, websites and other graphics.
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. Waffle slabs tend to be deeper than the equivalent ribbed slab. The slab is the flange of the beam and the extended part is the web. Hello bd, could you please design a flat slab with detailed reinforcement using prota structures. Ribbed slabs oneway joists introducing voids to the soffit of a slab reduces dead weight and increases the efficiency of the concrete section. Normally the ribs and the beams are the same depth. Continuous ribbed slabs concrete structures eurocode. On the technical drawings, reinforced concrete slabs are often abbreviated to r. Design of ribbed slab in etabs civil engineering community. The columns are used to provide support to the directly. Ribbed and waffle slabs types, advantages, disadvantages. In waffle slab design where the drop panels create a large critical shear perimeter, the factor b o d has limited contribution and is traditionally neglected for simplicity and conservatism. Posttensioning may be included in both slabs and beams to balance a percentage of the selfweight. The ribs are categorized as ribbed slab and waffle slab.
According to the coffered slab system definition, this slab has a network of ribs that form a square mesh, covered by a reinforced concrete plate. Civilax is the knowledge base covering all disciplines in civil engineering. Jul 22, 2015 design of two way ribbed slab 18 x 25 m clear span 1. As a standalone program, it analyzes and designs individual floor levels one at a time. Modelling ribbed slab if you just want it to look right, create a new profile. A slightly deeper section is required but these stiffer floors facilitate longer spans and provision of holes. Like flat slabs, ribbed slabs can be posttensioned. Ribbed and waffle slabs provide a lighter and stiffer slab than an equivalent flat slab, reducing the extend of foundations. Ribbed slab design in sap2000 civil engineering community. Jun 06, 2019 like flat slabs, ribbed slabs can be posttensioned. Ribbed slab design spreadsheet free download description.
Ribbed slabs are made up of wide band beams running between columns with narrow ribs. A ribbed slab with total thickness of 300 mm may have a selfweight equal to 3. There must be full shear connection, so that the design compressive force in the concrete, nc,f is. The type of slab presented in this paper is a coffered precast one.
Apr 27, 2014 civilax is the knowledge base covering all disciplines in civil engineering. This will result in further material efficiency with the volume of concrete reducing by a further 10%, a total saving of 30% on a typical flat slab solution. Join us for this webinar on designing structural castinplace slabs in tekla structural designer. This form of construction is not very common because of the formwork costs and the low fire rating. Reinforced concrete design examples geotec software. Ram concept offers an easier way of modeling waffle slabs in my opinion, but even then the design can be rather tedious i suspect that a lot people simplify the problem. How to design ribbed slab with autodesk robot structural analysis but, if you use light beamsor supports at the part of the nervedrib structure of the slab can it work, i mean using separate objects, one for the ribs and another thin slab to. The ribbed slab ubc 1816 or pti design method was developed by the posttensioning institute from an earlier effort made by the prestressed concrete institute that had been based on research by the building research advisory board of the national academy of sciences in the 1950s. The depth of the slab in compression, for full shear. Slabs are actually structural members made for floors and roofs in buildings which may be formed of solid thickness or ribbed with ribs running in one or two directions. The continous slab will be designed as a series of simply supported spans.
Ribbed slab design spreadsheet civil engineering downloads. Two way rcc slab designing excel sheet civil engineering. How to design ribbed slab with autodesk robot structural. Check the applicable joist dimensional limitations as follows.
Aug 15, 2016 download code ribbed slab design spreadsheet. Models can have columns, braces, walls, and ramps connected from the floors. Flat slab analysis and design free version download for pc. The analysis and design follow the equivalent frame analysis method of the aci code, which considers a onebay wide strip of the floor system as a continuous frame. Integrated reinforced and posttensioned concrete slab design software adaptfloor pro product overview with its ability to model full multistory concrete buildings, floor pro delivers value beyond other singlelevel slab design programs. The design procedure includes determini ng slab thickness based on moving live loads and then checking adequacy of slab thickness for stationary live load. You can use a combination of slab and beam elements, but by default those will be centered vertically which isnt quite right analytically speaking and dealing with offsets can get complicated.
Ribbed slab systems we have an extensive range of precast, prestressed, slab systems which provide a fast, cost effective and simple solution for any suspended slab requirement. Analysis of two way ribbed and waffle slabs with hidden beams. For general design philosophy and analysis of posttensioned concrete, the reader should refer to pdhonline course s127. Reinforced concrete slab and beam design software adaptrc 2017 product overview an easytouse and learn software for the design, analysis, and investigation of reinforced nonprestressed concrete beams, beam frames, slabs and floor systems a must have production tool in every structural engineering office.
In this webinar well present the methodologies for slab design. The sheet is designed for all nine types of panels and gives details about middle strip as well as edge strip reinforcements in the rcc slab. Well go over the steps for a successful design, introduce our unique patch method, compare and contrast to traditional strip methods and export the reinforcing drawing to a dxf. There are two main types of ribbed floors a hollow block floors and b moulded floors as shown in figure 8. The icons have a bright color palette, smooth and wellrounded edges. 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 this is a part of his project economic design of two way rcc slabs under prof s. They provide a very good form of construction where slab vibration is an issue, such as laboratories and hospitals. Ribbed slabs are made up of wide band beams running between columns with narrow ribs spanning the orthogonal direction. In this video you will learn how to analyze and design different slab types plate and ribbed slabs prota software. A ribbed raft consists of a stiffened slab by girders in x and ydirections.
Ribbed slabs are made up of wide band beams running between columns with narrow ribs spanning the. Design of two way ribbed slab 18 x 25 m clear span 1. Visual interest ribbed slabs are being used by architects to give visual interest when exposing the slab soffit. The ratio of the total costs was found to be within the range 1. Ribbed slab design spreadsheet civil engineering community. The girders on the raft may be either down or up the slab. Ribbed slab in design in safe civil engineering community. Oneway simply supported slab analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter.
The structural modeling used in most commercially available software, where stems are considered as disjointed from the topping slab does not deliver the advantages associated with waffleslab slab construction. This gives you complete waffle slab design with rebar detailing and schedules. Comparison between ribbed slab structure using lightweight foam concrete and solid slab structure using normal concrete. See more ideas about waffle ceiling, architecture and ceiling design. Ribbed slab floors are most economical for buildings such as hospitals, schools, hotels, and apartment construction where loads are somewhat small and the spans are relatively large. This way, you can work depending on project and status, as required by your personal workflow. One method is to ignore the weight of the solid part of the slab in the analysis of the ribbed slab and the weight of the solid area added to the supporting beam. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems. The load on this slab is carried by the short span in a direction but the main reinforced bar and distribution bar in transverse direction. It has got detailed worked example of all cocncete elements, including ribbed and waffle slabs. In ribbed slab, there is oneway spanning and in a waffle slab, there is twoway ribbed system. Twoway ribbed slab system waffle system the system was designed to decrease the weight of traditional fullconcrete slabs. They are either oneway spanning systems known as a ribbed slab or a twoway ribbed system known as a waffle 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. In this video you will learn how to analyze and design different sl. In reality, sandwich slabs are ribbed slabs with a slab placed both to their upper and lower surface. The domeshaped forms create a matrix of voids surrounded by orthogonal ribbing, producing a twoway configuration very suitable for largespanning slabs. Civilax on beam design with excel using coefficient method. For the purposes of analysis and design, the ribbed slab will be replaced with a solid slab of equivalent moment of inertia, weight, punching shear capacity, and oneway shear capacity.
Planbar is the cad solution specifically for the precast concrete industry. A slab is structural element whose thickness is small compared to its own length and width. They are either oneway spanning systems known as ribbed slab or a twoway ribbed system known as a waffle slab. Reinforced concrete slab and beam design software adaptrc.
Concrete slab design software free download concrete. Jun 27, 2017 ram concept offers an easier way of modeling waffle slabs in my opinion, but even then the design can be rather tedious. Pdf comparison between ribbed slab structure using. Using these entries, it is possible to design the rib as a downstand or upstand beam with effective slab widths in rfconcrete members. A study on a twoway posttensioned concrete waffle slab. Oct 28, 2017 design two way ribbed slab using sap 2000 2000 duration. The new version of the fem structural slab design software includes adaptations to european standards, e.
Safe provides an immensely capable yet easytouse program for structural designers, provideing the only tool necessary for the modeling, analysis, design, and detailing of concrete slab systems and foundations. 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. To easily select slabs, click on the dimension tag titled 1s2 as seen below for the main reinforcement bars. They provide a very good form where slab vibration is an issue, such as laboratories and hospitals. Course content this spreadsheet program provides for the design and analysis of posttensioned concrete oneway beam and slab systems and twoway flat plate slab systems. Protastructure professional structural engineering software duration.
You can perform reinforcement designs, long term deflections, beam designs, reactions, automatic two way action, effective moment of inertia, and punching shear. The plain view of this slab has a square shape, having the length of 2800mm, as presented in fig. Ribbed slab design spreadsheets to eurocode 2 en 19921. Concrete floor slabs on grade are subjected to a varie ty of loads and loading conditions. Ribbed slabs waffle slabs zoellner, sandwich can be used for large spans, like the one shown in the figure.
Flat slab analysis and design designs beamless concrete slab floors flat slab or waffle slab in accordance with aci 318. Summary of bill of quantities civil works bar bending schedule. Reference 5 focused on analysis of twoway ribbed slabs with. Ribbed slab design in sap2000 civil engineering downloads. Ribbed and waffle slabs provide a lighter and stiffer slab than an equivalent flat slab, reducing the. Twoway joist waffle slab design approach and methodology. Ribbed floors consisting of equally spaced ribs are usually supported directly by columns. The design procedure separately incl udes determining thickness of slab under wall load. A concrete slab is a common structural element of modern buildings, consisting of a flat, horizontal surface made of cast concrete.
Project specific slab designs are created using an optimised combination of prestressed. This is a part of his project economic design of two way rcc slabs under prof s. Using udls simplifies the analysis and remains popular. Ribbed rafts can be used for many structures when a flat level for the first floor is not required. Planbar combines the advantages of threedimensional models and excellent drawing preparation.
When a slab is supported on all four sides and the proportion of the long span to the short span is less than 2. Design spreadsheets in high rise buildings and skyscrapers, thinner, precast concrete slabs are slung between the steel frames to form the floors and ceilings on each level. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. Twoway joist concrete slab floor waffle slab system. They might assume an equivalent stiffness solid plate, or they might model the beams in both directions like a grid with no slab at all, or they might focus on a single strip.
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