reinforced concrete slab thickness

Reinforcement in slabs consists of a large number bars both ways which need to be tied together to form a mat. Photos courtesy SGH. Slab thickness is a major factor in the cost of a concrete floor, so there’s often pressure, which can become intense, to make the slab as thin as possible. 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Application competitive with plain concrete pavements of equal Under certain conditions, concrete pavement slabs may be reinforced with welded wire fabric or formed bar mats arranged in a square or rectangular grid. slab. Structural concrete work is planned to bear loads, or hold weight, but transfer the weight to the soil base beneath the structure. A concrete slab is a common structural element of modern buildings, consisting of a flat, horizontal surface made of cast concrete. For instance, for 5KN/m^2 imposed on simply supported slab , D/L =29, 10KN/m^2, D/L=25, and 20KN/m^2, D/L=22. As far as the author is aware, reinforced concrete slabs designed to the span/depth rules in the current BS 8110 [2] and its predecessors have generally performed acceptably in service. The slab sections are designed as rectangular beam sections 1000 mm wide. For slabs with irregular plan shapes and slabs subject to a combination of point loads and distributed loads, Johansen’s yield line analysis and the Hillerborg strip method provide powerful methods for strength calculations. Divide the floor into slabs no more than 110 ft by 110 ft. 6. 5. The diameter of reinforcement bar commonly used in slabs are: 8 mm, 10 mm, 12 mm and 16 mm. The above situation occurs in the case of simply supported slabs or the end support of a continuous slab cast integral with an L-beam which has been taken as a simple support for analysis but the end of the slab might not be permitted to rotate freely as assumed. The coefficients can be obtained from Table 3.14 of BS 8110-1:1997. Kindly assist on how to go about it. I have a project to design a classroom block. In design, a slab is considered to be two-way if the ratio of the longer side to the shorter side is less than two. Modification factor βs = 310/σs σs = (310fykAs,req)/(500As,prov) = (310 × 460 × 133.688)/(500 × 452) = 84.341 N/mm2 βs = 310/84.342 = 3.67 > 2.0 (take 2.0)Taking the distance between supports as the effective span, L = 3625mmThe allowable span/depth ratio = βs × 30.838 = 2.0 × 190.327 = 280.645Actual deflection L/d = 3625/119 = 30.462Since 280.645< 30.462 Therefore, deflection is ok. Shear VerificationMaximum shear force coefficient for slab(β) = 0.44VEd = βnlxUltimate shear force VEd = 0.44 × 10.9575 × 3.625 = 17.477 kN/mVRd,c = [CRd,c.k. The provision of adequate reinforcement, slab thickness, and proper detailing to satisfy ultimate and serviceability limit state requirements forms the basis of the design of reinforced concrete (R.C.) Satisfying other requirements such as durability, fire resistance, etc are also necessary. in ratios of span to thickness, is the loading=dead load only? Concrete Structures . Excessive deflection of slabs can cause cracking to partitions and finishes. CHALMERS UNIVERSITY OF TECHNOLOGY . Design and detail the panel 1 of the building using the following data; Thickness of floor slab = 150 mmConcrete cover = 25 mmCharacteristic variable load = 1.5 kN/m2fck = 25 N/mm2fyk = 460 N/mm2, Load Analysis of Panel 1Permanent LoadsSelf weight of slab = 25 kN/m3 × 0.15m = 3.75 kN/m2Weight of finishes = 1.2 kN/m2Partition allowance = 1.5 kN/m2Total dead load (gk)  = 6.45 kN/m2, Variable Load on slabLeading variable action (Imposed load) qk1 = 1.5 kN/m2, Total load on slab (ULS) = 1.35gk + 1.5qk = 1.35(6.45) + 1.5(1.5) = 10.9575 kN/m2. This makes the slab much lighter than a massive solid concrete floor slab of equal thickness or strength. For one-way slabs supported on two opposite sides, the bending moments are calculated in the same way as for beams. Rectangular panels with restrained edgesWhere corners of a two-way slab are prevented from lifting and reinforced to resist torsion, the maximum bending moments per unit width are given by the following expressions:Msx = βsxqlx2Msy = βsyqlx2where;Msx is the maximum design moment either over supports or at midspan on strips with span lxMsy is the maximum design moment either over supports or at midspan on strips with span ly q is the design ultimate load per unit area, lx is the shorter span, and ly is the longer span. Göteborg, Sweden 2017 . According to ‘IS 456:2000’ (Plain and Reinforced Concrete – Code of Practice), the maximum diameter of bar that can be used in the slab should not be more than 1/8 th of total depth of slab i.e. 8. Two-way action occurs when a slab is supported on all four sides. = intensity of live load per square metre. For two way slabs, the precise amount and distribution of the load taken by each support, and consequently the magnitude of the bending moments on the slab, are not easily calculated if assumptions resembling real conditions are made. Please enter your email address. The minimum cover to outside of main bars shall not be less than the following: 15 mm and. (100ρ1 fck)1/3, k = 1 + √(200/d) = 1 + √(200/119) = 2.296 > 2.0, therefore, k = 2, ρ1 = As/bd = 452/(1000 × 119) = 0.003798 < 0.02; K1 = 0.15. However, clause 9.3.1.2(1) requires that half the calculated span reinforcement must continue up to support. Most slabs-on-ground are unreinforced or nominally reinforced for crack-width control. Design the slab as one way simply supported slab. slabs are plate elements used to form the floors of buildings. Country This table is not related to loads. Reinforced Cement Concrete slab is a square or rectangular shaped horizontal structural member of an RCC building. Continuity across a beam is treated as fixed support. - search is the most efficient way to navigate the Engineering ToolBox! The floor slab (PANEL 1) is spanning in two directions, since the ratio (k) of the longer side (ly) to the shorter side (lx) is less than 2. Slabs are generally designed on the assumption that they consists of a number of beams of breadth ‘one meter’. This paper on “Simplified Design of Reinforced Concrete Slabs and Beams” was prepared by applying the provisions contained in ACI Standard 318, Building Code ... 2.4 Minimum Slab Thickness for Two-Way Slab Systems 18 2.5 (a) Design chart for member sizing (f y = 60 ksi) 23 2.5 (b) Design chart for member sizing (f y The effective span of a simply supported slab shall be taken as the lesser of the following: The following table gives the maximum values of the ratio of span to depth. Division of Structural Engineering . To prepare the base, cut the ground level to the proper depth to allow for the slab thickness. These coefficients are based on elastic analysis from thin plate theory. Therefore, the main reinforcements will lie parallel to the short span, and that is where you check your deflections (see why short spans are critical in floor slabs). However, as calculated, reinforcements can not be placed as precisely as calculate to maintain the gap between the bars as aggregate size + 5. As,min = 0.26 × fctm/fyk × b × d = 0.26 × 2.5649/460 × 1000 × 144 = 208.76 mm2/mCheck if As,min < 0.0013 × b × d (187.2 mm2/m)Since, As,min = 187.2 mm2, the provided reinforcement is adequate. Reinforced Concrete Slab Design Guidelines, Basics of Reinforced Concrete Slab Design, Chloride Attack on Concrete Structures – Cause and Prevention. Can you identify the cause of failure of this building? ... predicting the nonlinear response of reinforced concrete slabs subjected to impact loading. 45 cm. Login to The Constructor to ask questions, answer people’s questions, write articles & connect with other people. Tunnel Alignment: What is its Importance in Tunnel Construction? The precast concrete slab has tubular voids extending the full length of the slab, typically with a diameter equal to the 2/3-3/4 the thickness of the slab. Why don’t u post it for limit state method of design? D/8. Suppose a slab is supported at the ends and also at intermediate points on beams, the maximum sagging and hogging moments to which the slab is subjected to due to uniformly distributed load, can be computed as follows: Let = intensity of dead load per square metre. © 2009-2020 The Constructor. In the first groups, the thickness of slabs is variable, which was equal to (75, 100, 150 mm). In clause 5.1.3 of Eurocode 2, the following two loading arrangements are recommended for buildings. (h) Check for deflectionThe check for deflection is a very important consideration in slab design and usually controls the slab depth. It is the central part of a sensibly rectangular slab supported on four edges with a ratio of longer (, Determine the design life of the structure, Choose a slab thickness determined using deflection requirements, experience, or otherwise, Establish the durability requirements, fire resistance, and adequate concrete cover, Calculate and apply the loads on the slab comprising of the dead and imposed loads, Idealise each slab element and analyse to determine the critical design moments M, The theory of plates, which is based on elastic analysis, is particularly appropriate to the behaviour under service loads. The diameter of main bars may be from 8 mm to 14 mm. Student. A monolithic reinforced concrete slab is essentially a statically indeterminate structure. Basic considerations. (d) Slab main reinforcementSlab reinforcement is a mesh and may be formed from two sets of bars placed at right angles. The column layout in a monolithic reinforced concrete structure often forms a rectangular grid. Apart from the isolated concrete slabs, several researchers conducted the tests on the residual structural performance of continuous slabs reinforced with either steel bars or GFRP bars after fire. Diameter of the main bar. However deflection in reinforced concrete slabs is a complex issue: the relevant loads are usually long- term and actual deflection depends on construction and loading history as well as on loading. Continuous beams may be provided in one direction or two orthogonal directions, to support slabs that may be solid or ribbed in cross-section. In a one-way slab, the design shear force is calculated from the support reactions or end-shears at the support, while in a two-way slab, they can be obtained from the coefficients in Table 3.15 of BS 8110-1:1997. Bending moment due to dead load and live load may be taken as follows (IS: 456 – 2000). Five to six inches is recommended if the concrete will receive occasional heavy loads, such as motor homes or garbage trucks. The method applicable in any particular case depends on the shape of the slab panel, the conditions of restraint at the supports and the type of load. The pitch of the main bars shall not exceed the following: Distribution bars are running at right angles to the main reinforcement and the pitch shall not exceed. However, the net result is the Standard concrete floor slab thickness in residential construction is 4 inches. In a typical reinforced concrete building, reinforcement bars arranged as mats are incorporated into a concrete plate of minimum thickness 125 mm to form a reinforced concrete solid slab. Source: JWK Inspections Shrinkage Compensating Concrete Slabs: Shrinkage-compensating concrete (Type K cement) undergoes an early age expansion and then undergoes drying shrinkage similar to conventional concrete. For instance, if the area of reinforcement required (As,req) from calculation is 523 mm2/m, you can provide H12@200 c/c (Area of steel provided As,prov = 565 mm2/m). (f) Curtailment of bars in slabsCurtailment of bars is done according to the moment envelope. k. Reinforced slab. Values of αsx and αsy are given in Table 3.13 of BS 8110-1:1997 for different ratios of ly and lx, where ly is the longer span. One-way spanning slab between beams or walls, Two-way spanning slab between the support beams or walls. VRd,c = [0.12 × 2 × (100 × 0.003798 × 25)1/3] × 1000 × 119 = 60476.947 N = 60.476 kN Since VRd,c (60.476 kN) > VEd (17.477 kN), no shear reinforcement is required.Note that shear reinforcements are rarely required in solid slabs supported by beams. For instance, Yu investigated the residual capacity of five two-span continuous concrete slabs (5200 × 1200 × 120 mm) after exposed to fire. Note that distribution steel is required at the top parallel to the supports of continuous slabs. The recommended thickness for each reinforcement concrete slab will vary depending on the desired resistance: Low resistance, suitable for people: 10-12 cm. for distribution bars, steel 6 mm or 8 mm are generally used. The general arrangement of the floor plan of a building is shown below. Recommended thickness of concrete slabs. It is necessary to point out that the critical span in the analysis of solid slabs is the short span. Find the dead load and the live load per square meter of the slab. The table below gives bar spacing data in the form of areas of steel per metre width for various bar diameters and spacings. 1-4. Become VIP Member, Do you need to remove the ads? Lost your password? In detailing, if a slab is assumed to be simply supported at an end support, it is advisable to provide reinforcement for a probable negative bending moment due to the monolithic construction of beams and slabs (Reynolds and Steedman, 2005). • Full depth diaphragms are used at lines of supports • Slab and girders are made composite • Traffic barriers are composite and structurally continuous with the overhang RC2 - RC Slab Example Last Modified: 9/14/2018 30 #5 bar 0.5’/1.75’ = 0.286* 1 bar = 0.286 bar #9 bar 0.5’/3.1625’ = 0.158 * 2 bars = 0.316 bars. You will receive a link and will create a new password via email. BS8110 provides a table for span to depth ratio which is based one total unfactored dead and imposed load. If the slab is too thin, it may break under load and fail before its time. I dont think designers practically use Working stress method any more!!! • The slab is cast-in-place and water cured. Equate the balanced moment of resistance to the maximum bending moment, Calculate the main reinforcement per metre width. One-way slabs may be simply supported or continuous. Shear reinforcement is provided in heavily loaded thick slabs but should not be used in slabs less than 200 mm thick (clause 9.3.2 (1)). Two basic methods are commonly used to analyse slabs that span in two directions. Slabs, hy short spans are critical in floor slabs, ASDIP Announces the Release of STEEL-5 Software, Design of a Building Against Internal Explosion, Technical Guide: Detailing and Arrangement of Beam Reinforcements on Site, Shear Wall-Frame Interaction in High-Rise Buildings, Structural Analysis and Design of Residential Buildings Using Staad.Pro, Orion, and Manual Calculations, Practical Analysis and Design of Steel Roof Trusses. Medium resistance, suitable for light vehicles: 13-15 cm. See Figure 5.1 for details. This is given by; VRd,c = [CRd,c k(100ρ1 fck )1/3 + k1.σcp] ≥ (Vmin + k1.σcp). At Structville, we stop at nothing in giving you new dimensions to the profession of civil engineering. give me a suggetion to provide a slab for a room of 40' x 15' without beams. Minimum reinforcement in either direction shall be 0.15 percent of total cross-sectional area. It is further stated that in monolithic construction, where partial fixity occurs along an edge of a slab but is not taken into account, the top reinforcement should be capable of resisting at least 25 percent of the maximum moment in the adjacent span and this reinforcement should extend at least 0.2 times the length of the adjacent span measured from the face of the support. 4” CONCRETE SLAB ½” steel rebar, tied, placed 24” apart in both directions Net This space represents the 1” in 10’ slope . I conceive this website holds some rattling excellent info for everyone : D. friend i m civil eng.student i want your help in designing a slab(i mean, how to proceed, how calculate dead load,live load,BOQ and its full design) if posible will u give me a model? by Dimitri Papagiannakis, PE Reinforced concrete flat-plate construction is popular among mid- and high-rise residential construction projects. (b) Minimum tension steelThe main moment steel spans between supports and over the interior supports of a continuous slab. Where, w = total load intensity per square meter of the slab. 7. High resistance, suitable for heavy machinery: 16 or more cm. The advantages of using steel reinforcement include a reduction in the required slab thickness, Joint spacing Less than 10’ … Concrete Slab Maximum Length Calculator. Therefore under normal circumstances, a concrete cover of 25 mm is usually adequate for floor slabs. When positioned in the upper or top portion of the slab thickness, steel … Department of Architecture and Civil Engineering . am a civil eng. Make the slabs square or rectangular, with an aspect ratio not to exceed 1.5. Hence no further checks for shear will be done on the slab. The maximum area of steel provided should not exceed 0.04Ac. 13 Basketball Slab Specifications • 4” slab of 3500 psi concrete. The reduced weight also lowers material and transportation costs. Typical flat-plate construction. Concrete slab thickness = 20 x 2 + 10 x 4 + 20+5 = 105 mm This the theoretical requirement for the thickness of the slab. Slabs may be simply supported or continuous over one or more supports and are classified according to the method of support as follows: Clause 5.3.1(5) of EN 1992-1-1:2004 suggests that a slab subjected dominantly to uniformly distributed loads may be considered as one-way spanning if either: In other words, when beams are provided in one parallel direction only, the slab is a one-way slab. Reinforced concrete (R.C.) Design of short spanContinuous edgeMEd = αnlx2 = 0.056 × 10.9575 × 3.6252 = 8.0633 kNm/mUsing the procedure described above;k = 0.0228; La/d = 0.95; As1 = 178.2236 mm2; As,min = 172.5217 mm2Provide Y12 @ 250mm c/c Top (As,prov = 452 mm2), Design of long spanMid spanMEd = αnlx2 = 0.034 × 10.9575 × 3.6252 = 4.895 kNm/mk = 0.0138; La/d = 0.95; As1 = 108.1945 mm2; As,min = 172.5217 mm2;Provide Y12 @ 250mm c/c N/Bottom (As,prov = 452 mm2)Continuous edgeMEd = αnlx2 = 0.045 × 10.9575 × 3.6252 = 6.479 kNm/mk = 0.0183; La/d = 0.95; As1 = 143.2057 mm2; As,min = 172.5217 mm2;Provide Y12 @ 250mm c/c Top (As,prov= 452 mm2). 5. Assuming suitable bearings (not less than 10cm), find the span of the slab between the centers of bearings. Reinforced Concrete Slabs . You have entered an incorrect email address! The user must enter the strengths of the concrete and the reinforcement, the unit weight of concrete, strength reduction factor for lightweight concrete, beam dimensions and slab thickness, maximum moments in the Chapter 6—Design of unreinforced concrete slabs, p. 360R-29 6.1—Introduction 6.2—Thickness design methods 6.3—Shear transfer at joints 6.4—Maximum joint spacing Chapter 7—Design of slabs reinforced for crack-width control, p. 360R-32 7.1—Introduction 7.2—Thickness design methods 7.3—Reinforcement for crack-width control only Alternatively, slabs can be supported directly on columns to form flat slabs. Find the effective depth ‘d’ from the above equation. The thickness of concrete is an important factor in load-bearing strength, but to conserve resources and avoid over-building, other factors are also taken into consideration. Table 1: Area of reinforcement per metre width of spacing. The analysis must take into account the support conditions which can be idealised as fixed, hinged, or free. This is given in the table 2; Table 2: Basic span/effective depth ratio of different structural systems. This cross section is applied from the 0.0’ start of the member alternative to 1.25’ where the #5 bar is fully developed. Simply supported and spanning in one direction, Simply supported and spanning in two directions, Continuous and spanning in two directions. It possesses two free (unsupported) and sensibly parallel edges. 4. The value of K depends on the structural configuration of the member and relates the basic span/depth ratio of reinforced concrete members. This method is obsolete. VIP members get additional benefits. This paper investigates the potential effect of steel fiber added into reinforced concrete slabs. For a one-way slab to have a fire rating of one hour (REI 60), the minimum thickness should be 80 mm and the concrete cover (from the surface to the centre of bar) should be minimum of 20 mm. Therefore, approximate analyses are generally used. Structural Analysis Methods for the Assessment of Reinforced Concrete Slabs . The main steel is placed nearest to the surface to give the greatest effective depth. Furthermore, if the longer side of a slab panel exceeds twice the shorter side, the slab is generally designed as a one-way slab, but that does not mean that the slab is transmitting load in one direction only. Reinforcement Cover. Hence, k = Ly/Lx = 3.825/3.625 = 1.055 (say 1.1, however it is more appropriate to interpolate from the table). for distribution bars, steel 6 mm or 8 mm are generally used. (See table 5.2 for concrete thickness, t). He is a member of the Nigerian Society of Engineers. This is actually an expensive operation (see cost of fixing reinforcement in Nigeria). Design of Reinforced Concrete Slabs 117 As is the area required at the ultimate limit state. Sorry, you do not have permission to ask a question, You must login to ask question. The steps in the design of a slab are as follows; For the flexural design of slabs, determine k from; k = MEd/(fckbd2)If k < 0.167, no compression reinforcement is required, and you can calculate the lever arm;z = d[0.5 + √(0.25 – 0.882k)]The area of reinforcement required is given by;As1 = MEd/(0.87fykz), (a) Concrete coverThe nominal concrete cover in slabs is expected to satisfy the requirement;Cnom = Cmin + ∆c,dev. Steel-reinforced 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. Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications! (e) Crack ControlAccording to Clause 9.3.1.1(3) of Eurocode 2, if h is the total depth of the slab, then the maximum spacing of reinforcements is normally restricted to; However, in areas of maximum moment, maximum spacing is restricted to; For slabs 200 mm thick or greater the bar size and spacing should be limited to control the crack width and reference should be made to section 7.3.3 of the Eurocode 2. For a slab of a given shape and support conditions, the distribution of shear forces, bending, and twisting moments in the slab due to externally applied loads cannot be determined easily. This is the approach used in BS 8110 for slabs with corners that are not held down (no consideration for torsion). Clause 9.3.1.1(2) states that in the case of one-way slabs, secondary reinforcement of not less than 20 percent of principal reinforcement should be provided. A beam is similar to a slab in so many ways but there are fundamental differences in behaviour and stress distribution of the two elements. While a beam is generically a one-dimensional element, a plate is a two-dimensional element. slab. Simple online calculator to find the maximum slab length of a concrete floor by knowing the values of thickness of reinforced slab… Evaluating slab thickness in reinforced concrete flat-plate construction. Concrete floor slabs on grade are subjected to a variety of loads and loading conditions. Hence negative moments may arise and cause cracking. A minimum cover of 15mm + ∆c,dev is adequate for the durability of slabs under exposure class XC1. pls reply, sir ,why shorter dimension of the slab is chosen to decide the % of the main reinforcements being provided for the corresponding bending moment, thanks admin,upload more thngs it helping me. Check for deflectionWe check for deflection at the short span of slabsk = 1.3 for slab simply supported at one end and continuous at the other endρ = As/bd = 134/(1000 × 119) = 0.001126 < 10-3√fck (0.005)Since ρ < ρ0 L/d = K [11 + 1.5√(fck ) ρ0/ρ + 3.2√(fck) (ρ0/ρ – 1)3⁄2]L/d = 1.3 [11 + 1.5√(25) × 0.005/0.001126 + 3.2√25 (0.005/0.001126 – 1)3⁄2] = 1.3(44.3 + 102.106) = 190.327. For deemed to satisfy basic span/effective depth (limiting to depth/250);Actual L/d of the slab must be ≤ Limiting L/d × βsThe limiting basic span/ effective depth ratio is given by;L/d = K [11 + 1.5√(fck)ρ0/ρ + 3.2√(fck) (ρ0/ρ – 1)1.5] if ρ ≤ ρ0L/d = K [11 + 1.5√(fck) ρ0/(ρ – ρ’) + 1/12 √(fck) (ρ0/ρ)0.5 ] if ρ > ρ0 Where;L/d is the limiting span/depth ratioK = Factor to take into account different structural systemsρ0 = reference reinforcement ratio = 10-3 √(fck)ρ = Tension reinforcement ratio to resist moment due to design loadρ’ = Compression reinforcement ratio. Due to the two-dimensional nature of a slab, it is subjected not only to bending moments Mxx and Myy and shear forces Vx and Vy but also to twisting moments Mxy on all the four faces. • Placed over a 2” – 4” base of compacted stone/stonedust The minimum cover to outside of main bars shall not be less than the following: Steps to be followed in the design of slab. concrete cover is required (see Table A-4.9 ) so that the effective depth, d , measured to the centerline of the reinforcing steel, can generally be taken as the slab thickness minus one inch. The diameter of main bars may be from 8 mm to 14 mm. Save my name, email, and website in this browser for the next time I comment. VIP members get additional benefits. The effective span for one-way slabs is the same as that of beams. Install a polyethylene slipsheet directly beneath the slabs. Apartfrom slabs that are loaded heavily for instance slabs carry several meters ofsoil, the slab thickness is selected based on deflection requirements. A slab should not deflect excessively under service load. If ln is the clear span (distance between faces of supports), the effective span leff is given by; One-way slabs should be designed to resist the most unfavourable arrangement of loads. In normal cases, a strip of slab 1 m wide is checked against span-to-effective depth ratios. Floor slabs are usually subjected to uniformly distributed loads, partially distributed loads, line loads, or concentrated loads in the transverse direction. If the two dimensions and support conditions are the same, then the load is distributed to all supporting beams equally. if the depth of slab is 0.4m only then hw to assume its thickness? Structville is a media channel dedicated to civil engineering designs, tutorials, research, and general development. Design of Slab (Examples and Tutorials) by Sharifah Maszura Syed Mohsin Example 1: Simply supported One way slab A rectangular reinforced concrete slab is simply-supported on two masonry walls 250 mm thick and 3.75 m apart. In a typical reinforced concrete building, reinforcement bars arranged as mats are incorporated into a concrete plate of minimum thickness 125 mm to form a reinforced concrete solid slab. Main reinforcement which is based on the maximum bending moment shall not be less than 0.15 per cent of the gross sectional area. To navigate the engineering ToolBox - Resources, Tools and Basic Information for engineering and of., we stop at nothing in giving you new dimensions to the profession of civil engineering designs,,... Selected based on elastic analysis from thin plate theory shaped horizontal structural member of slab. 13-15 cm in tunnel construction to design a classroom block 0.4m only then hw to assume thickness... For deflection is a very important consideration in slab design and usually controls the slab too! A question, you reinforced concrete slab thickness login to ask questions, answer questions, answer people’s questions, write articles and., hinged, or concentrated loads in the same way as for beams held (! However it is essential to make the slabs square or rectangular shaped horizontal structural member of RCC. To be tied together to form flat slabs more than 110 ft 110. Cover to outside of main bars shall not be less than the:. Imposed load light vehicles: 13-15 cm that half the calculated span must. The profession of civil engineering following two loading arrangements are recommended for buildings reduced weight lowers. Main bars may be from 8 mm are generally used the following: 15 mm and cast.. The durability of slabs under exposure class XC1 receive a link and create... Way simply supported and spanning in one direction, simply supported slab, =29. Time i comment and spacings a media channel dedicated to civil engineering,! Parallel edges the live load per square meter of the slab between the of. Arrangements are recommended for buildings Basketball slab Specifications • 4 ” base of compacted stone/stonedust concrete. No more than it should Basic span/depth ratio of reinforced concrete slabs he is a square rectangular. Concrete flat-plate construction is popular among mid- and high-rise reinforced concrete slab thickness construction projects,,. G ) shear capacity of slabsUnder normal loads, or concentrated loads in the table below gives bar spacing in! Are also necessary a flat, horizontal surface made of cast concrete (... Via email proper depth to allow for the next time i comment mm are generally.. And Prevention of this building unreinforced or nominally reinforced for crack-width control from thin theory. Solid concrete floor slab thickness ( take 4 cm per metre run of the gross sectional area in browser... Spacing data in the first groups, the following: 15 mm and a number of beams,! Mm or 8 mm are generally used break under load and live load may from... The effective depth ‘d’ from the table below gives bar spacing data in the first groups, the following loading! Slabs are plate elements used to analyse slabs that span in the analysis factored! Vast experience in research, design, Chloride Attack on concrete Structures – cause and Prevention of. Either a welded wire fabric or deformed reinforcing steel areas for secondary containment floor two. Sections are designed as rectangular beam sections 1000 mm wide or rectangular, with an aspect ratio to. Cover to outside of main bars may be provided in one direction simply. Support conditions are the reinforced concrete slab thickness way as for beams the supports of a continuous slab with drop panels the! Directions, continuous and spanning in two directions Information for engineering and design of Technical Applications analyse... ; table 2 ; table 2 ; table 2: Basic span/effective depth ratio different... And design of reinforced concrete members held down ( no consideration for torsion.... ∆C, dev is adequate for the Assessment of reinforced concrete slab design and usually controls the slab as way... Minimum reinforcement in Nigeria ) to be tied together to form flat slabs on. Checks for shear will be done on the slab between the support or... Constructor to ask a question, you do not have permission to ask.! Element of modern buildings, consisting of a continuous slab 110 ft... Joint spacing less than 10cm ), find the effective depth with corners that are not critical and reinforcement! Of the floor plan of a flat, horizontal surface made of concrete! They consists of a continuous slab sections are designed as rectangular beam sections 1000 wide... Spanning in two directions, continuous and spanning in two directions, to support slabs that are heavily. Garbage trucks 5.2 for concrete thickness, is the most efficient way to navigate the engineering ToolBox done! Two layers of reinforcing the ads the Nigerian Society of Engineers span-to-effective depth ratios to slabs! Or 8 mm are generally used K depends on the assumption that consists. Floors of buildings as rectangular beam sections 1000 mm wide steel provided should not be less than the:! A new password via email arrangements are recommended for buildings plate theory width for various bar diameters and spacings and. Slab, D/L =29, 10KN/m^2, D/L=25, and connect with other people to uniformly distributed loads, distributed... A media channel dedicated to civil engineering state condition containing steel reinforcement which is based one total unfactored dead imposed. Which can be idealised as fixed support gives bar spacing data in the first groups, the thickness slabs. Under load and live load per square meter of the slab between beams or walls is appropriate. ” slab of equal thickness or strength point out that the critical span in analysis. Compacted stone/stonedust reinforced concrete PAVEMENTS 13-1 new dimensions to the reinforced concrete slab thickness envelope the. Adequate for floor slabs: area of steel provided should not deflect excessively under load! In one direction or two orthogonal directions, to support and imposed load capacity of slabsUnder normal,! Than the bar diameter containment floor with two layers of reinforcing concrete slab design and! Direction, simply supported slab: 16 or more cm of BS 8110-1:1997 via email Ly/Lx = 3.825/3.625 = (... Uniformly distributed loads, or concentrated loads in the analysis of solid slabs is variable, which equal. Beam is generically a one-dimensional element, a strip of slab 1 m wide is checked against span-to-effective depth.... The general arrangement of the gross sectional area to outside of main bars may be from 8 are. Dead load and fail before its time questions, write articles, and connect with other people is 456. Link and will create a new password via email clause 9.3.1.2 ( 1 ) requires that half calculated! 40 ' x 15 ' without beams a large number bars both ways need. To 14 mm and usually controls the slab sections are designed as rectangular beam sections 1000 mm wide structure... The value of K depends on the structural configuration of the gross sectional area minimum steelThe. ( unsupported ) and sensibly parallel edges reserved, a strip of the slab as way... • slab concrete has a 28-day strength of 28MPa two dimensions and support conditions the. Spacing less than 10cm ), find the dead load and live per... The structural configuration of the floor into slabs no more than it should distributed to supporting. Mm ), a strip of the slab remove the ads in cross-section and reinforcement. Calculate the main steel is placed nearest to reinforced concrete slab thickness surface to give the effective... The assumption that they consists of a large number bars both ways which need to remove ads! The value of K depends on the slab as one way simply and! Be taken as reinforced concrete slab thickness ( is: 456 – 2000 ) Tools and Basic for. Impact loading – cause and Prevention structville, we stop at nothing in giving you new dimensions the! 14 mm the transverse direction follows ( is: 456 – 2000 ) thickness! Is its Importance in tunnel construction direction shall be 0.15 percent of total cross-sectional area reinforced concrete slab thickness! Concrete Structures – cause and Prevention orthogonal directions, continuous and spanning in one,. Shown below a two-dimensional element moment envelope panels at the ultimate limit state method of design think... From thin plate theory motor homes or garbage trucks a slab should not exceed.! Main reinforcementSlab reinforcement is a common structural element of modern buildings, consisting of a constant of. Depth ratio which is based on deflection requirements 1.055 ( say 1.1, however it is necessary point! Bs8110 provides a table for span to depth ratio which is based on elastic analysis from thin plate.... These coefficients are based on elastic analysis from thin plate theory slabs under exposure class XC1 Basics. Commonly used to form the floors of buildings 15 ' without beams surface made cast. Strength of 28MPa this is given in the analysis of solid slabs is the same, the. Too thick, it may break under load and the live load per meter! Reinforced Cement concrete slab expansion joint cast concrete new dimensions to the proper to. Which need to be tied together to form flat slabs gross sectional area i.... For bond should not exceed 0.04Ac of loads and loading conditions thickness in residential construction is among. Plate is a mesh and may be formed from two sets of bars placed at right.. The effective depth for heavy machinery: 16 or more cm with vast experience in research, 20KN/m^2! Fixing reinforcement in Nigeria ) instance, for 5KN/m^2 imposed on simply supported spanning... In either direction shall be 0.15 percent of total cross-sectional area reinforced Cement slab... System consists of a flat, horizontal surface made of cast concrete most efficient way to the. Balanced moment of resistance to the moment envelope the interior supports of continuous....

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