A slightly deeper section is required but these stiffer floors. Flat slabs design is appropriate for most floor situations and is also suitable for irregular column layouts, curved floor shapes, ramps etc. For an additional 9 years he was a principal advisor to the california legislature on infrastructure and capital outlay issues. Pdf comparison between ribbed slab structure using. Expertise and reinforcement of a particular ribbed. 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. Ribbed slabs are constructed with wide band beams which run through amid columns having equal depth narrow ribs across the orthogonal direction. Through the years we followed the progress of this method where all of the floor slabs are cast at ground level one atop the other, then raised as a group and dropped off one by one. The reason why, concrete and steel are used together to construct rcc slab, is in their individual properties as. Comparison between ribbed slab structure using lightweight foam concrete and solid slab structure using normal concrete. Plastic support chairs hold the tendons in the center third of the slab depth.
The structural depth of domes is the full height of the dome from base to crown. Because of the ribs and double reinforcement, it is more stable and recommended for larger span slabs or foundations. Preservation of historic concrete requires a thorough understanding of the causes and types of deterioration, as well as of repair and replacement materials and methods. Generally, slab on grade is classified into three types.
Fire behavior of the assembled monolithic hollowribbed slabs. Volume 3, issue 8, august 2014 issn 2319 4847 numerical. They provide a very good form of construction where slab vibration is an issue, such as. This ribbed slab is ready for concrete placement, with a moisture barrier placed over the subgrade after interior beam forms have been cut into the earth. Hi artur 1 how can i medel one way ribbed slab top slab and ribs with arsa. And as you can see i left it in the same stateas it was at the end of the previous videowhere we tweaked the edges of the slab justby dragging the. Ribbed slab design spreadsheet civil engineering community. In oneway ribbed slab, loads are transferred in one direction, and the main reinforcement is distributed in the same direction of the. Ribbed and waffle slabs types, advantages, disadvantages. Design of reinforced concrete structures ii twoway slabs 1 1. The pti design procedure is used to design a slabon grade foundation that will respond.
Cost data from the most trusted source in north america. 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. May 10, 2017 ribbed or waffle slabs systems in the construction may 10, 2017 tose architecture, architecture article, architecture news, architecture tips, home design ideas, interior design 0 they are either oneway spanning systems know n as ribbed slab or a twoway ribbed system known as a waffle slab. Waffle slab or ribbed slab construction procedure and. Filler slab technology is a simple and a very innovative technology for a slab construction. A waffle slab is flat on top, while joists create a grid like surface on the bottom. Advantages of rib clay pot slab over solid concrete slab published on january, 2017 january, 2017 26 likes 2 comments. The spacing between the ribs should be in general 2030 inch.
They provide a very good form where slab vibration is an issue, such as laboratories and hospitals. Structural ribbed concrete slabs the cupolex floor slab can be fully or partially suspended on piles, stem walls or gradeedge beams. Ribbed slabs have been widely used in buildings due to their many advantages, especially the decrease of concrete below the neutral line. A slightly deeper section is required but these stiffer floors facilitate longer spans and provision of holes. Contraction control joint a formed, sawed or tooled groove in a concrete structure to create a weakened plane and regulate the location of. Static tests of the bending behaviour of the four pieces of the rcs specimens and one ordinary concrete castinplace slab were carried out.
In may 1958 concrete construction covered a project that used the lift slab method of raising floors, first introduced in 1950. Reference 5 focused on analysis of twoway ribbed slabs with. Editing the beam properties in its property dialogue. Foreword the reinforced concrete design manual sp1711 is intended to provide guidance and assistance to professionals engaged in the design of castinplace reinforced concrete structures. Rigid zones can be defined to prevent slab deformations at column locations. Analysis of two way ribbed and waffle slabs with hidden beams.
Ribbed floors consisting of equally spaced ribs are usually supported directly by columns. The roofs were evaluated using the life cycle assessment lca methodology. Experimental study on flexural behaviour of lightweight multi. Typical depth of flat plate ribbed slabs are in the range of 120117 of the lesser effective span. Waffle slab or ribbed slab is a structural component which is plain on its top and contains grid like system on its bottom surface. Posttensioning institutes design of posttensioned slabsonground, pti design procedure 3rd edition. Introduction to spread footings and mat foundations. The twoway steel grid method is less invasive and the most costeffective. Ribbed or waffle slab is a slab system which consists of series of parallel reinforced concrete t beams framing into reinforced concrete girders. Ribbed and waffle slabs provide a lighter and stiffer slab than an equivalent flat slab, reducing the extent of foundations. 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. Civilax is the knowledge base covering all disciplines in civil engineering.
Flat slabs are low cost structures due to the simplicity of the formwork and the quick construction process. Seismic retrofitting methods for the jack arch masonry slabs. This paragraph conducts to compute the maximum deflection of rc circular twoway ribbed slabs that occurred usually at the center of slab when uniformly distributed load has been applied. Adaptpt is the industry standard standalone program for the design of beam frames, slabs and floor systems posttensioned with either bonded, or unbonded tendons. Longer spans can be achieved due to pre stress, which can be used to counteract deflections posttensioned slabs use high strength tensioned steel strands to compress the slabs, keeping the majority of the concrete in compression. Jan 01, 2019 this paper deals with the problem of optimum design of reinforced concrete twoway ribbed waffle slabs using genetic algorithms. In case of hollow block slab voided blocks are placed to reduce the total weight of the slab. Twoway joist concrete slab floor waffle slab system.
They are either oneway spanning systems know n as ribbed slab or a twoway ribbed system known. The tutorial consist of ribbed slab design throught etabs. Editor paul guyer is a registered civil engineer, mechanical engineer, fire protection engineer, and architect with over 35 years experience in the design of buildings and related infrastructure. Advantages of rib clay pot slab over solid concrete slab. 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. Interactive database editing allows users to edit model data from a table view. Although isostatics can be drawn from the isoclinic diagram, the manual process is.
Purchase advances in concrete slab technology 1st edition. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems. Hollow blocks have a minimum crushing strength of 3. Ribbed slabs are made up of wide band beams running between columns with narrow ribs spanning the orthogonal direction. Flat slab design spreadsheets to eurocode 2 en 19921. Waffle slabs can be described as the equivalent of 2way solid slabs especially when the spans are large, and ribbed system is to be adopted. The ribbed floor slab systems of pier luigi nervi form finding lab. Concrete slab types construction, cost, and applications. Pdf design of reinforced concrete circular slabs by twoway. Jan 09, 2019 using slab pottery templates is a great way to consistently build a form over and over again. Additional reinforced internal ribs are then used in the slab. The production and construction p and c, operational energy oe, and. The ribbed slab was analyzed exactly by finite element theory.
The equivalent thickness based on moment of inertia is used to find slab stiffness considering the ribs in the. The concrete layer method is the most invasive and the least costeffective. Ribbed slabs oneway joists introducing voids to the soffit of a slab reduces dead weight and increases the efficiency of the concrete section. Prota structure modelling reinforced concrete members.
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. 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. The seismic behavior of these slab systems is studied by. Details title bim management services duration 60 mins language english format mp4 size 110 mb download method direct download download links download. Highlights three different methods of seismic retrofitting jack arch slabs are investigated. Concrete floor slabs on grade are subjected to a varie ty of loads and loading conditions. Pt slabs offer the thinnest slab type, as concrete is worked to its strengths, mostly being kept in compression.
Example on structural design of waffle slab structville. This paper presents an experimental and computational study on ribbed slabs with widebeam, two oneway slabs and two twoway slabs. This part on structure which includes modeling grids, columns. First floor slab made by date sketch and plan sketch on hollow pot slab plan slab dimensions hollow pot slab width, b 3. The cupolex floor slab can be fully or partially suspended. Ribbed slab design spreadsheets to eurocode engineering. Bill is a fellow of the american concrete institute and is a licensed professional engineer. 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. Useful tips for design of rcc members rcc beam rcc slab. Ribbed slab system which consists of a series of parallel reinforced concrete t beams framing into reinforced concrete girders. The blocks are considered as nonstructural element as they do not contribute to strength of the slab. Designed as a series of parallel tbeams and economical for medium spans with light to. Waffle slab or ribbed slab construction procedure and advantages.
In case of hollow block slab voided blocks are placed to reduce the total weight of the. A joint that separates the slab structurally from other building elements such as walls, columns, foundations, drain pipes, to accommodate differential horizontal and vertical movement. He has been the editor in chief of concrete construction for 16 years. To develop new slabs with light weight and high rigidity as well as meet the requirements of use and facilitate construction, a largespan multi ribbed composite slab rcs with filled lightweight blocks is proposed based on systematic research. They provide a very good form where slab vibration is an. 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. Life cycle assessment of flat roof technologies for office. Comparison between ribbed slab structure using lightweight foam concrete and solid slab structure using normal concrete article pdf available march 2010 with 5,7 reads how we measure reads. The benefits of choosing flat slabs include a minimum depth solution, speed of construction, flexibility in the plan layout both in terms of the shape and column layout, a flat soffit clean finishes and freedom of layout of services and scope and. Slab design concrete slab design posttensioned concrete slab design pt slab slab. Detailed experimental data in the form of describing slab cracking or spalling, furnace temperatures, temperature distributions, and vertical deflections are presented. In this article, the author presents a parallel approach to.
This 300 mm deep ribbed slab is required for an office to support a variable action of 5 kn m2 it is supported. Continuous ribbed slabs concrete structures eurocode. Supported on continuous stiff supports are in the range of 125 of the lesser effective span. This paper presents the results from the furnace tests conducted on two assembled monolithic hollow ribbed amh slabs consisting of the open box and the covered box, respectively. Design of reinforced concrete structures ii twoway slabs. Expertise and reinforcement of a particular ribbed slab. It is important that adequate time is allotted during the planning phase of a project to provide for trial repairs and mockups in order to evaluate the effectiveness and. Introduction hollow block and ribbed slabs are formed by placing blocks on the slab and concrete ribs. 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.
Numbers in italics are the divisional responsibilities for each editor. The goal of the current study was to evaluate the environmental damage from three flat roof technologies typically used in israel. The slab which is cast on the surface of the earth is called a ground slab. Liftslab construction concrete construction magazine.
As simple as i can answer, a rib slab or ribbed slab is similar to flat slabs. Blocks may be made concrete with lightweight aggregate or other material as polystyrene foam. Ribbed slab design spreadsheets to eurocode 2 en 19921. Nervi, ribbed slabs, isostatics, floor systems, computational tool.
Tiebracing method does not provide the required integrity and strength. Ribbed slabs types and its advantages in construction. The top of ribbed slab is normally thin and the bottom grid lines are generally ribs which are laid perpendicular to each other with equal depth. The slab is the flange of the beam and the extended part is the web. 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. They provide a very good form of construction where slab vibration is an issue, such as laboratories and hospitals. The results of this analysis are compared with the results of the finite element method by sap program.
Teaching twoway ribbed slab analysis and design using the mathcad program mohammed s. The two methods ive seen the most to perform this has either been. The pti design procedure is used to design a slabon grade foundation that will respond elastically to forces the foundation is exposed to including those that are the consequence of soil pressure and soil deformation. Ribbed and waffle slabs provide a lighter and stiffer slab than an equivalent flat slab, reducing the extend of foundations. They are either oneway spanning systems known as ribbed slab or a. Animation showing the construction process of a reinforced concrete ribbed slab. Optimum design of a reinforced concrete ribbed slab. Effective depth of slab in ydirection d y 250 25 162 217 mm. Andrew avakian makes slab pottery templates to help generate new slab built forms. The study comprises of comparison of story displacement and story. Ribbed slab article about ribbed slab by the free dictionary. Ribbed or waffle slabs systems in the construction free.
Slab cast integrally with a series of closely spaced joist which in turn are supported by a set of beams. In case of ribbed slab the blocks are not permanent. 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. The ratio of the total costs was found to be within the range 1. An openaccess publisher of journals covering a wide range of academic disciplines,provides publishing serves the worlds research and scholarly communities. However, the north american provisions on punching shear of frp twoway slab are very conservative or nonexistent. Teaching twoway ribbed slab analysis and design using the. Conventional beam slab system, flat plate system, flat slab with drop system, and ribbed slab system. Andrew creates maquettes of possible new pieces using tagboard thick paper and then tweaks them until he creates the. The design procedure includes determini ng slab thickness based on moving live loads and then checking. Design example of punching shear in slabs eurocode 2. Ifon and ifthe opening in the slab cutsalso the ribsofthe ribbed plate,then new openingsare created in. Jan 08, 2016 watch 4th part of course series on scia engineer which is a powerful software that you will realize after learning full course.
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