The design of suspended floors should conform to requirements of aci 318 and aci 421. House slab classification vs soil classification home. In general, 6 inch 150mm slab thickness is considered for residential and commercial buildings with reinforcement details as per design. 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.
Flat slab analysis, design and detailing pdf civil engineering. Dhang, department of civil engineering, iit kharagpur. In addition to general ultimate and serviceability limit state design issues, practical design considerations such as the formation of holes in the slab, support details, fire protection, and attachments to the slab are discussed. Flat slab analysis, design and detailing pdf civil. Construction requirements the minimal thickness of the concrete layer above the profiled sheet should be. Oneway simply supported slab analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter. Find the following parameters for design moments in step 2 per unit width step 4 note. Dec 07, 2018 this video shows the different types of slab and their subtypes.
Framing dead load selfweight superrimposed dead load 25 psf partitions, me, misc. Slab is a horizontal flexural member like the member. Reinforced concrete sk 33 section through slab showing stress due to moment. Following are the rcc slab design and detailing guidelines. A new method for designing floor slabs on grade due to the difficulty of applying simplified design methods, amongst them being the portland cement association pca and wire reinforcement. 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.
Using aashto lrfd bridge design specifications 4th ed. The slab has to carry a distributed permanent action of 1. Two way concrete slab having 100mm thickness and dimension as shown in figure below, supported deal load of 6knm2 and live load of 3knm2 wu 1. An advising party would need to know the area, see the soil report and possibly visit the site. However, from a quick glance a friend told me that the slab used by my builder is only m class. The design procedure set forth in that publication had at that time been in use by the author for about 15 years. Flat plate concrete floor system does not use beams between columns or. Oneway and twoway slabs university of asia pacific. Design of reinforced concrete structures ii twoway slabs 1 1. Twoway slab design static equilibrium of twoway slabs total moment in both beams full load was transferred eastwest by the planks and then was transferred northsouth by the beams. A slabonground shall be designed and constructed either in accordance with as 2870 or as. The design of composite slabs and beams is discussed in detail in relation to the eurocodes and bs 5950. Select representative 1 m wide design stripstrips to span in the.
The performance of the footings and slab or both is largely depended upon a responsible approach by the builder and. Department of mechanics, materials and structures english. Residential slabs and footings construction requirements. Besides being a medic, he loves blogging, and he always strives hard to share the highquality content with others. Class p concrete shall contain 70 percent to 80 percent portland cement and 20. Reinforced concrete design 1 design of slab examples. The design procedure includes determini ng slab thickness based on moving live loads and then checking adequacy of slab thickness for stationary live load. 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. The elements can be triangular, rectangular or quadrilateral. Design of concrete structures shall be based on the requirements and guidance cited. The service live load is 100 psf, and 4000 psi concrete is specified for use with steel with a yield stress equal to 60,000 psi. Jun 24, 2014 in general, ground movement on class h1 and h2 sites is a bit more serious than class m and class s sites. Posttensioned concrete design table 11 list of symbols used in the aci 31808 code m bal design moment resistance of a section with tendons and the necessary mild reinforcement to reach the balanced condition, nmm m u factored moment at section, lbin n c tension force in concrete due to unfactored dead load plus live load, lb p. 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.
May experience moderate ground movement as a result of soil conditions and moisture changes. There are three main types of slab while each main type have their subtypes. Founded in 1904 and headquartered in farmington hills, michigan, usa, the american concrete institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensusbased standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design. Design of slab for flexure 067 m unit width of slab. Where soils in class m, h and e sites are subject to. Laboratory trial mix for class p concrete must produce an average 28 day flexural strength of at least 650 psi. What is a soil test and how is it used to design house.
Pdf design of flat slab worked example mohamed hussein. A combination of these values will determine the slab stresses at the time of stressing and at service loads. For beamless slabs, the choice between a flat slab and a flat plate is usually a matter of loading and span. The following example illustrates the design methods presented in aci 31805 and ibc 2003.
Class 5000 concrete may be used with the approvals of the. Bending will take place in the two directions in a dishlike form. In general, ground movement on class h1 and h2 sites is a bit more serious than class m and class s sites. Concrete floor slabs on grade are subjected to a varie ty of loads and loading conditions.
Structural details of slab culverts 3 for spans less than 3. The matter was considered especially important because the south african loading code was changed with effect from. Design of reinforced concrete 10th edition pdf free. Waffle raft slab also known as a waffle pod slab these slabs are constructed entirely above the ground by pouring concrete over a grid of polystyrene blocks known as void forms. Advantages and disadvantages of each of these slab designs are.
The floating slab gate uses the natural force of line pressure to obtain a dynamically tight downstream seal in highpressure differential applications. A 2 2area 2 a c 2 2 posttensioned concrete design table 11 list of symbols used in the aci 31808 code cp area enclosed by the outside perimeter of the section, in a g gross area of concrete, in a 2 l total area of longitudinal reinforcement to resist torsion, in a o area enclosed by the shear flow path, sqin a oh area enclosed by the centerline of the outermost closed. Tm 580912 concrete floor slabs on grade subjected to heavy. Design of reinforced concrete 10th edition pdf free download. The fabricated body allows for a wide selection of material choices. The slab is positioned on steel tbeams which can be rolled or compound. Along with the site class, the type of building construction affects the choice of footing. Tm 580912 concrete floor slabs on grade subjected to. Can anyone give me an idea of how much an m class or h class slab would cost for a 44square house.
Its very common to have a 100mm slab maybe thats what the additional cost is or the mix of the concrete is to a higher mpa grade or both. This table details some of the special considerations and finishing techniques that are appropriate for each class of floor. A reinforced concrete slab is built integrally with its supports and consists of two equal spans, each with a clear span of 15 ft. The slab deflects in both direction and the loads transferred in all four edges. This report is intended to serve as a manual of good practice for the design of prestressed concrete flat slabs in addition to the recommended procedures, other methods are described for the sake of completeness and to compare different methods of design. Easy to use software becoming more widely available. The design procedure separately incl udes determining thickness of slab under wall load. Reinforced concrete slab design and detailing guide is456. Sep 03, 2011 reinforced concrete sk 33 section through slab showing stress due to moment. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. According to him, the h class slab requires some top bars that the builder subsequently decided are not necessary. Additional requirements for classes m, h1, h2 and e sites.
After this publication, it was subsequently adopted by the uniform building. This pdf file contains a chapter of 23 pages with various aspects of flat slabs including four example of flat slab design. Simply supported one way slab a rectangular reinforced concrete slab is simplysupported on two masonry walls 250 mm thick and 3. Pdf a new method for designing floor slabs on grade due to. Design the slab, following the provisions of the ack code. Design of reinforced concrete structures ii twoway slabs. In both of them, the shear resistance has to be determined by means of slab tests, however the total number of test can be considerably reduced, because once the longitudinal strength. For slabs, this will require a series of cross beams in the slab and sometimes piers too. Example on design of slab bridge design data and specifications superstructure consists of 10m slab, 36m box girder and 10m tgirder all simply supported. The footing and slab code starts introducing special requirements for drainage and for protecting. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems. The slab is 300 mm thick and columns are 400 mm square. Most class a and class s sites will only need a basic reinforced slab with concrete beam footings underneath the edges of the slab, while sites with other classifications will require the slab to be stiffened. Concrete structures chapter 5 wsdot bridge design manual m 2350.
The slab is for an offi ce where the specifi ed load is 1. The type of soil you are about to build a home on will determine the slab type needed. Floor classifications table 1 describes the nine classes of concrete floors according to aci 302, guide to concrete floor and slab construction. The same is true for a twoway slab or any other floor system where. Steel rods aiiia400 and steel wires bpi are used as reinforcement. But the engineering drawings are noted soil p design m, and seem to be providing only for a standard m class slab with 310mm edge beam depth, 85mm slab thickness, 85mm slab thickness pretty thin. Refer to aci 223 for procedures for the design and construction of shrinkagecompensating concrete slabs onground. It was found that a certain amount of poor design was prevalent, and the committee decided to produce a booklet of recommendations for good practice. Therefore, for the design problem under discussion, m lalb 1216 0. Accordingly, main reinforcement is required in the two directions.
Your homes slab type will then be designed, based on these results. Flat plate strength is often governed by shear strength at the columns, and for service live loads greater than perhaps 100 lbft2 4. Instructional materials complementing fema p751, design examples additive load w largest eccentricity combining loads on footings a5 and a6, applying the 0. There is no deemed to comply design for waffle slabs for extremely reactive sites class e sites. 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. Unless otherwise noted, all referenced table, figure, and equation numbers are from these books. Lecture series on design of reinforced concrete structures by prof. Thickness of concrete slab depends on loads and size of the slab. Why does a h1 class slab cost more than an m class slab. Class m md 2040mm moderately reactive clay or silt sites. The slabs may also need additional concrete footing embedded in the soil, depending on the soil type, and are generally suited to class m, class h and class e soils. Use of 500 grade steel in the design of reinforced concrete slab prof.
Design of slab examples and tutorials by sharifah maszura syed mohsin example 1. Load transfer in a oneway slab, b twoway slab nilson fig. The construction and design of concrete slabs on grade. As for your slab listed above, at 385 thick im tipping its a pod slab void form.