Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. Mathematical structural analysis of one way ribbed slabs was introduced in this paper. Comparison between ribbed slab structure using lightweight foam concrete and solid slab structure using normal concrete article pdf available march 2010 with. Jun 21, 1977 a process for constructing an improved floor slab for a reinforced concrete building, said process comprising the steps of. Jan, 2017 advantages of rib clay pot slab over solid concrete slab published on january, 2017 january, 2017 26 likes 2 comments. This 300 mm deep ribbed slab is required for an office to support a variable action of 5 kn m2 it is supported on wide beams that are the same depth as the slab, as shown in figure 3. The load on the slab is carried by the short span in one direction.
The ratio of the total costs was found to be within the range 1. This is attributed to the rapid shattering, ease of construction, and the reduction in the time of erection. Ribbed slab design spreadsheets to eurocode engineering books. Slabs are structural members forming floors and roofs in buildings. Crcm manual 4 crcm means concrete rib construction method, the word method, can create confusion, because the icc ibc uses such word in the section 1701. 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. Design of reinforced concrete structures ii twoway slabs 1 1. The thickness of equivalent flat slab is taken from table 9. Crcm manual 10 floor slab reinforced with fiber glass, when concrete is mixed with an additive which seal cracks with moisture, no sand and waterproof membrane are required, by exception r506. In this article, the author presents a parallel approach to the traditional teaching method of twoway ribbed slabs. Sep 03, 2011 reinforced concrete effective span centretocentre distance between supports longer dimension of a rectangular panel of slab for yield line calculations modular ratio esec design bending moment per unit width of slab modified to account for axial load moment per unit width about xaxis moment per unit width about yaxis. If the ribs are provided in one direction only, the slab is classified as being oneway, regardless of the ratio of longer to shorter panel dimensions. Example on structural design of waffle slab structville. The reason why, concrete and steel are used together to construct rcc slab, is in their individual properties as separate building materials and their individual limitation.
First of all, it depends on the use of the structure. Because of the ribs and double reinforcement, it is more stable and recommended for larger span slabs or foundations. Ribbed slabs can be used in oneway and twoway edge supported slabs. But crcm uses concrete a material used more than 3,000. The floor consists of six panels at each direction, with a panel size 24 ft x 20 ft. In case of ribbed slab the blocks are not permanent.
In sap program, the model has been divided to frame elements to represent ribs and beams and shell elements to represent the slab and solid part. The ribs are categorized as ribbed slab and waffle slab. The saving of materials tends to be offset by some. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
Ribbed floors consisting of equally spaced ribs are usually supported directly by columns. With bodacious bulbousness, ribbed is perfect for those designs that take themselves too seriously. For joist depth determination, waffle slabs are considered as flat slab aci. The historical discussion includes the evolution of the floor slab from a nonstructural element to an inspired structural system, culminating in nervis patented ribbed floor systems. Jul 15, 2017 ribbed slab design ribbed floors consisting of equally spaced ribs are usually supported directly by columns. Slab cast integrally with a series of closely spaced joist which in turn are supported by a set of beams. Additional reinforced internal ribs are then used in the slab by introducing pontex, the structural cupolex accessory to provide a structure capable of spanning between foundations or piles. The results of this analysis are compared with the results of the finite element method by sap program. The slab is the flange of the beam and the extended part is the web.
Structural ribbed concrete slabs the cupolex floor slab can be fully or partially suspended on piles, stem walls or gradeedge beams. Flat slab analysis, design and detailing pdf civil. Continuous ribbed slabs concrete structures eurocode. Ribbed slab design spreadsheets to eurocode engineering. Pdf comparison between ribbed slab structure using. Equivalent thickness based on shear area calculation in waffle slab design where the drop panels create a large critical shear perimeter, the factor b. In ribbed slab, there is oneway spanning and in a waffle slab, there is twoway ribbed system. Analysis of two way ribbed and waffle slabs with hidden beams ibrahim mohammad arman international journal of civil and structural engineering volume 4 issue 3 2014 345 length and l2 is the transverse distance or frame width. Ribbed slab floors are most economical for buildings such as hospitals, schools, hotels, and. They provide a very good form of construction where slab vibration is an issue, such as laboratories and hospitals.
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. Advantages of rib clay pot slab over solid concrete slab. This strip can then be analyzed by the methods that were used for rectangular beams, the bending moment being computed for the strip of unit width. Ribbed slab design spreadsheet civil engineering community. Waffle slab or ribbed slab construction procedure and advantages. Ribbed can help you lighten up designs with just the click of a button. This form of construction is not very common because of the formwork costs and the low fire rating.
In oneway ribbed slab, loads are transferred in one direction, and the main reinforcement is distributed in the same direction of the load. Ram concept offers an easier way of modeling waffle slabs in my opinion, but even then the design can be rather tedious. Comparison between ribbed slab structure using lightweight foam concrete and solid slab structure using normal concrete. Advantages of rib clay pot slab over solid concrete slab published on january, 2017 january, 2017 26 likes 2 comments. Our new crystalgraphics chart and diagram slides for powerpoint is a collection of over impressively designed datadriven chart and editable diagram s guaranteed to impress any audience.
Ribbed slabs oneway joists introducing voids to the soffit of a slab reduces dead weight and increases the efficiency of the concrete section. However main reinforcement bar and distribution bar in transverse direction. Ribbed slabs are made up of wide band beams running between columns with narrow ribs spanning the. Comparison between ribbed slab structure using lightweight foam concrete and solid slab structure using normal concrete article pdf available march 2010 with 5,070 reads how we measure reads. Their function is the same as any slab, to support loads coming from the roof and ultimately to the ground and to also act as a floor. Concrete is good in taking compression and steel is good in tension. Accordingly, main reinforcement is required in the two directions.
Pdf the ribbed floor slab systems of pier luigi nervi researchgate. Reinforced concrete effective span centretocentre distance between supports longer dimension of a rectangular panel of slab for yield line calculations modular ratio esec design bending moment per unit width of slab modified to account for axial load moment per unit width about xaxis moment per unit width about yaxis. Reference 5 focused on analysis of twoway ribbed slabs with. Department of mechanics, materials and structures english. Full character set, with central european accents and symbols. Ribbed slab a panel composed of a thin slab reinforced by ribs in one or two directions, usually at right angles to one an other. Design of reinforced concrete structures ii twoway slabs. Civilax is the knowledge base covering all disciplines in civil engineering. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems.
Mar 12, 2016 the tutorial consist of ribbed slab design throught etabs. Economy of construction is obviously an important consideration, but this is a qualitative argument until specific cases are discussed, and is a geographical variable. Waffle slab plan view reinforcement detail faculdade. As simple as i can answer, a rib slab or ribbed slab is similar to flat slabs. 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.
The continuous slab is folded at at least one beam defining path across its planar supporting surface and preferably includes a right angle grid of such folds with downward peripheral folds at the slab edges and downward vsectioned folds to interrupt the. Jul 22, 2015 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. Twoway joist waffle slab design approach and methodology. They may be solid of uniform thickness or ribbed with ribs running in one direction or two directions waffles. The tutorial consist of ribbed slab design throught etabs. Under the general provisions of the 1995 code, chapter, the twoway joist portion may be combined with a solid column head or with solid wide beam sections on the column centerlines for uniform depth construction. Lecture 25 design of twoway floor slab system 1 lecture 25 design of twoway floor slab system. Ribbed and waffle slabs types, advantages, disadvantages. With accurate to temperature and shrinkage, minimum of. In general, the beam slab flexural stiffness ratio is about 0. 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.
Cupolex can be used to create beams so that aerated floors become selfbearing. The cupolex floor slab can be fully or partially suspended. The spacing between the ribs should be in general 2030 inch. Designed as a series of parallel tbeams and economical for medium spans with light to medium live loads. Folded slab floor construction and method international. Ribbed is a new display typeface, great for headlines, posters, and making patterns. Slabs are usually used in floor and roof construction. A slightly deeper section is required but these stiffer floors facilitate longer spans and provision of holes.
Bending will take place in the two directions in a dishlike form. They are either oneway spanning systems known as ribbed slab or a twoway ribbed system known as a waffle slab. In general, it is seen that in solid slab a portion of concrete below the neutral axis remains ineffective. In case of hollow block slab voided blocks are placed to reduce the total weight of the slab. Civil engineering spreadsheets, civil engineering ebooks and many more civil engineering downloads. Pdf this paper presents an historical and analytical evaluation of the ribbed floor slab systems developed by the italian structural artist pier.
Aug 15, 2016 download code ribbed slab design spreadsheet. The blocks are considered as nonstructural element as they do not contribute to strength of. While the isostatic inspiration for the rib patterns of nervis floor systems is well. A reinforced concrete floor is constructed from a continuous slab defining a major and planar supporting surface. A wide variety of ribbed slab options are available to you, there are 305 suppliers who sells ribbed slab on, mainly located in asia. Which slab is better ribbed slab or solid slab one way or two way.
Structural slab forming solutions over the past 3 decades, the idea of placing concrete over cupolex. Teaching twoway ribbed slab analysis and design using the mathcad program mohammed s. 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 pdf file contains a chapter of 23 pages with various aspects of flat slabs including four example of flat slab design. There are two main types of ribbed floors a hollow block floors and b moulded floors as shown in figure 8. If the soil is unsuitable to hold the slab load design, pontex is used which in turn will. The columns are used to provide support to the directly. The two methods ive seen the most to perform this has either been. Filler slab technology is a simple and a very innovative technology for a slab construction. Ribbed and waffle slabs provide a lighter and stiffer slab than an equivalent flat slab, reducing the extent of foundations. Ribbed slabs ribbed slabs mat slabs california slabs 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 ribs are tapered in crosssection in its lower part. Analysis of two way ribbed and waffle slabs with hidden beams. The design of waffle slabs is the same as that of ribbed slabs, with the difference being that waffle slabs have ribs spanning in both directions, and the coefficients used for analysing the slab is similar to those used for twoway restrained slab.
I havent heard of anyone creating a family to generate a ribbed slab. Teaching twoway ribbed slab analysis and design using the. Please practice handwashing and social distancing, and check out our resources for adapting to these times. Which slab is better ribbed slab or solid slab one way.
This type of slabs or flooring system consists of series of small closed. Jun 27, 2017 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 article about ribbed slab by the free dictionary. Ribbed slab design in sap2000 civil engineering community. The thickness of slab and depth of rib of waffle slab can be then computed by equalizing the moment of inertia of equivalent flat slab to that of waffle slab. Ribbed slab design spreadsheet civil engineering downloads. Different between solid slab and ribbed hollow slab uae. Jul 02, 20 introduction hollow block and ribbed slabs are formed by placing blocks on the slab and concrete ribs. Introduction hollow block and ribbed slabs are formed by placing blocks on the slab and concrete ribs.
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