Use of voided slab is spreading all over the world in recent times. Before plastic voided slabs can be fully understood, a thorough knowledge of flat plate reinforced concrete slabs behavior, failure mechanisms, design, and limitations is critical. May 21, 2017 different types of concrete slabs in construction. Open spandrel arches enable relatively long spans, more commonly built in steel or prestressed concrete, to be built efficiently in reinforced concrete. Understanding the concept of bubble deck civil engineering.
Voided slabs are a precast prestressed slab for bridge, building, marine pier and fish passage culvert replacement applications. The reinforced concrete slabs with plastic void formers are designed. In this article, ill give a detailed explanation of each slab where to use particular slab. Nov 25, 2017 what is u boot technology uboot beton is a formwork made of recycled polypropylene. Flexural behavior of selfcompacting concrete voided slabs. The casted structural member is then transported to the construction site and then erected.
The slabs were bd 230 mm with a fixed floor layer of 30 mm. Voided slab is a method of virtually eliminating all concrete from the middle of a floor slab, which is not performing any structural function, thereby dramatically reducing structural dead weight. The form of construction where concrete is casted in a reusable mould and then cured in a controlled environment precast plant is called precast concrete. Structural members such as concrete frame, concrete wall and concrete floors etc. Flat slab system is an important division of concrete floor system. Design of bridge slab spreadsheet engineering books. Diagram of a concrete slab of hollow core construction photograph of a hollowcore assembly a hollow core slab, also known as a voided slab, hollow core plank or simply a concrete plank is a precast slab of prestressed concrete typically used in the construction of floors in multistory apartment buildings. Bubbledeck is the patented integration technique of linking air, steel, and concrete in a twoway structural slab. Voided slab concrete building technology free 30day. A comparative design of reinforced concrete solid slab bridge. Design, serviceability, fire resistance, and construction. There are 16 different types of slabs in construction. To investigate the punching shear capacity of the scc voided slabs five slabs of dimension. Void form work placed in between the top and bottom reinforcements of slab.
Design and experimental study of voided slab with proposed. Comparison of the experimental and theoretical values of punching shear capacity is done. The noise reduction with bubbledeck was 1 db higher than hollow core. This floor system allows for large, clear spans and efficient overall slab thicknesses.
Solid slab, voided slab and skew slab bridge decks are detailed out for analysis and design. Comprehensive design example for prestressed concrete psc girder superstructure bridge with commentary task order dtfh6102t63032 us customary units submitted to the federal highway administration prepared by modjeski and masters, inc. Sep 01, 2019 this is only valid when considering the voided biaxial slabs technology. The method of deck construction can be applied anywhere conventionally pouredinplace concrete is specified, such as flat plate, beam and slab, and wallbearing structures. These slabs can be used in applications where slab depth may be an issue or when construction speed is a factor. A combination of these values will determine the slab stresses at the time of stressing and at service loads. Aug 27, 2015 guide to the design and construction of reinforced concrete flat slabs contents membersof the projectsteeringgroup list of tables vii iv list of figures v 1. Hollow biaxial slabs, also known as biaxial voided slabs, are reinforced concrete. The total height of the bubble deck slab elements is constant, the diameter of bubbles that are used may be the total height of slab ie230,280,340,390 or 450mm minimum grade of concrete that is used for the construction of slabs are m20 or m25 different methodologies of creation of voids the bubble deck slab gaps elements can be delivered by. Flat slab analysis, design and detailing pdf civil engineering. Voided slab systems were first introduced in europe in the 1990s. The concept centers on removing concrete mass from the areas of the slab where it is not structurally efficient. Ice manual of bridge engineering ice virtual library.
The construction industry is one of the main contributors to the production of large volumes of greenhouse gases, since it consumes a large quantity of energy and construction materials. Design guide for vibrations of reinforced concrete floor. Buildinghow products books volume a the reinforcement. Comparison of carbon dioxide emissions of the ordinary. Design guide for voided concrete slabs crsi resource.
Voided concrete slabs rely on recycled materials and generate far less waste. Intended as a companion volume to the authors limit state design of reinforced concrete published by prenticehall of india, the second edition of this comprehensive and systematically organized text builds on the strength of the first edition, continuing to provide a clear and masterly exposition of the fundamentals of the theory of concrete design. Rehabilitation criteria for posttensioned voidedslab. The highest contributor to co 2 reduction is the embodied carbon dioxide emissions of the building materials, which accounts for 34,966 kg co 2. Voided slabs remove the excess concrete from the unnecessary part of the structure slab to reduce weight. Reducing greenhouse gas emissions and costs with the. Field tests in a raw building in leiden, the netherlands, concerning air and contact noiseresistance. Department of mechanics, materials and structures english.
A voided slab system is an efficient construction method that reduces the concrete deadload or selfweight, to enable an increase in the span of a building or structure aguado et al. This reduction in the flexural stiffness of voided slabs could be attributed to following. Biaxial hollow slab with innovative types of voids. Punching shear strength of reinforced concrete slabs with. Evaluation of the floor impact sound insulation performance. A flat slab is a oneway or twoway system with thickenings in the slab at the columns and load bearing walls called drop panels figure 9.
Comprehensive design example for prestressed concrete girder. The purpose of this research is to assess the environmental impacts and economic efficiency of the voided slab system compared to the ordinary reinforced concrete slab. Manual of standard practice, 29th edition isbn 97819439668. The idea was to create a hollow biaxial slab with the. Since the 1990s, many european companies have patented their own voided slab systems. Design methods edit a concrete deck using the filigree method of construction is designed using virtually the same techniques as are used for castinplace decks as. Experimental research of real scale biaxial voided slabs is performed. Beginning with voids made of 100% recycled plastic, this approach lowers the building s carbon footprint makes good use of abundant materials.
Advanced reinforced concrete design engineering books. Some of them are outdated and many of them are frequently used everywhere. Design of bridge slab spreadsheet reinforced slab bridges used for short spans, a solid reinforced concrete slab, generally cast insitu rather than precast, is the simplest design to about 25m span, such voided slabs are more economical than prestressed slabs. Five oneway simply supported slabs were tested including one as a reference slab solid slab and the remaining four as voided slabs with three cases of reduction in cross sectional area 6. Cost comparison between conventional slab and bubble deck slab. They increase the shear capacity and the stiffness of the floor system under vertical loads, thus increasing the economical span range.
Accessories connection bridge spacer joint closing plate 6. Voided biaxial slabs, sometimes called biaxial slabs, are a type of reinforced concrete slab which incorporates airfilled voids to reduce the volume of concrete required. Truss type voided slab truss spacings span between props 190 thick slab mm m t1100 320 3. A civil engineer must know all the aspects regarding the flat floor system.
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. As the span increases, the optimum form of construction changes to voided slab or beam and slab then box girder bridges. As regards bottom slab and top and bottom slabs of box with cushion due to dispersal of loads either through walls or through fills effective width loses its applicability. Manual of standard practice, 29th edition isbn 97819439668 committee on manual of standard practice on. Voided slab system has many advantages over conventional solid slab and some drawbacks also.
Savings in useful height on each level as there are no emerging beams. Guide to the design and construction of reinforced concrete. Current rehabilitation practices for aging, posttensioned, voided slab bridges typically reduce the geometric properties of the concrete cross section and so permanently increase posttensioning stresses, change primary and secondary prestress moments, and create new primary and secondary moments because the original concrete restrains. Here, we have tried to gather various reading materials available in the web about flat slab floor system in one place. Comparative study of flat plate slab and voided slab. Hollow slabs with innovative types of voids manmade. As a result, most uses of plastic voided slabs have occurred in europe. Dimensions uboot beton normally 52cmx52cm and manually 10, 16, 20, 24,28 cm in height. This design guide presents stateoftheart practices in voided slab construction. Waste reduction extends to both concrete and steel in construction and at the end of a structures useful life. The existence of a construction defect andor deficiency does not constitute a breach of this express limited warranty. A method for calculating the perimeter of the equivalent punching zone is proposed.
The measurements and ratings were carried out in regulation with iso 7171. Voided slab free download as powerpoint presentation. Civil engineering important code books download irc codes irc 6 2000 irc 18 2000 irc 21 2000 irc 22 1986 irc 24 2001 irc 78 2000. The compatibility of these foreign techniques must be workout with indian standards. There is a lot scope for studying the voided slabs in india. Two plastic voided slab brands, bubbledeck and cobiax, have also. Sandwich slab reinforcement details in reality, sandwich slabs are ribbed slabs with a slab placed both to their upper and lower surface.
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