S. TWO WAY SLAB DESIGN SPREADSHEET:Fig 10: Reinforcement of a slab. 3 For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall ‘be rounded off in accord-Table 5. The Clear. It is mainly to prevent upward bending moment near the joint. 6 Reinforcement 5. Minimum number of reinforcing bars required. A distribution bar is equal to (total slab length- 2x clear cover length)/center to center spacing of the bars + 1. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. from deviations in bar spacing and bar size are shown in figure 5. Unit weight for feet per metre = (D2/ 533). Area of reinforcement per metre width of spacing. 26. 25 x 87 =34. slab, shall not. In RC slabs and PT one-way slabs, the clear distance between bars is limited to the smaller of. 04𝑚𝑚2 𝑎𝑏 113. As per ACI Code, In slab, minimum reinforcement shall be 0. where. 4 bar at the top and the bottom of the footing or one No. Always main bar use in shorter span. Step 2: Calculation of cutting length ( for main bars and distribution bars) Cutting length of main bar = Clear span of slab + (2 × Development Length) ( 2 × D e v e l o p m e n t L e n g t h) + Inclined Length - Bend Length. from deviations in bar spacing and bar size are shown in figure 5. of chair bars = Area of structural reinforcement in sqm / chair bar per sqm. 1 specifies the requirements of ACI 7. 33=16 no’s. 2 Specific requirements for QA Stockists 26 4. assume corners are held down. 5, which is more than 2. A minimum of three bars evenly placed in the lap length is required. L is the required length of the Steel bar of Diameter D. Slab steel bar not less than 10mm dia. Effective depth=d provided =120-20-4= 96 mm. Unit weight of concrete = 25 kN/m 3. 2 of IS 456 :2000 , the reinforcing bars shall not exceed 1/8 of theThe minimum size and grade of rebar for slabs depends on a variety of factors, such as the thickness of the slab, the loads it supports, seismic requirements and other factors. 4. 7. 93 m 2 ) = 469. 230/0. 5d = 5 * 130 = 650 mm. 5. . 36 Live load Canopy = 1. 1% of the slab cross-sectional area) through sawcut contraction joints in combination with the recommended joint spacing. 2. 1—Early-age concrete material strength development 4. Base slab width b= 0. The distribution bars provide the following functions in slab construction: 1. The cross‐sectional area of one N28 bar is As = 620 mm2 and with N12 stirrups at 150 mm centres, Atr = 110 mm2. In this article I will explain you complete slab design as per IS 456 code by using manual method. 8 say 16 nos. f d n §· ¨¸ ¨¸ ©¹ ©¹ Since the required nominal moment from Section 1 (M n,reqThe Chinese code “Code for composite slabs design and construction” (CECS273:2010) states [34] that steel-bars truss can work with concrete as upper and lower bearing reinforcement in concrete, but without considering the role of steel-bars truss as a whole and bottom PSS, the bearing capacity of SBTS is calculated according to ordinary. Calculation of area of steel. That is 11′. 1—Minimum flexural reinforcement in nonprestressed slabs 8. 2, The diameter of reinforcing bars shall not exceed one-eighth of the total thickness of the slab. TWO WAY SLAB DESIGN SPREADSHEET:Fig 10: Reinforcement of a slab. 3. (b) One-way joist systems in accordance with 9. 5 inches (Singh & Saini, 2019). 1 General== a 1 in direction of 11 • = a, in direction of 12 • angle between the axis of a strut and the bars in the i-th layer of reinforcement crossing that strut. The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. 9. Unit weight of concrete = 25 kN/m 3. If redistribution is carried in design, the allowable max spacing needs to be reduced or relaxed as per table 15 of IS456. Slab steel bar spacing maximum 150mm c/c. c. f ck = 25 Mpa. This is plotted against the overall fire rating of the structure that is being designed. Generally # 3 or # 4 bars are used for slab main reinforcement. 7—Reinforcement detailing 8. Near lapped joints, if the diameter of the longitudinal bar is greater than 14 mm. This chapter shall apply to the design of nonprestressed and prestressed beams, including: (a) Composite beams of concrete elements constructed in separate placements but connected so that all elements resist loads as a unit. Number of Required Bars Formula = (Length of slab / spacing) + 1. In Seismic Design Categories D 0, D 1 and D 2, slabs-on-ground cast monolithically with turned-down footings shall have not fewer than one No. 18% of gross sectional area (B×D), taking B= 1m width of slab and D= overall depth including cover, then minimum reinforcement will be = 0. The bigger span in the above slab, 5000, divided by the shorter span, 2000, is 2. However, it is not a code, so many engineers do use portions of ACI 318 on their projects. Abstract. 3, the maximum spac- c) Spacing of bars: The maximum spacing of bars shall not exceed Main Steel – 3d or 300 mm whichever is smaller Distribution steel –5d or 450 mm whichever is smaller Where, ‘d’ is the effective depth of slab. rainfall intensity in inches per hour for the building location specified in the plumbing code. Dowel bars require care in placement to minimize. 6 Live Load. The. Total Cutting Length Of Rod = 2nos x 1. Dia of Bar to be provided 'd' = 16 mm (round bar) Area of cross-section of 1 bar = 0. Provide main reinforcement of 10 mm diameter bars at 120 mm c/c. 5. 17 x 10 6 )/ (1000 x 119 2 x 25) = 0. Step 1. e. 347. 6. 6. Distribution Bar. How do you calculate slab distribution bar? Formula = (total length – clear cover)/center to center spacing + 1 main bar, = (5000 – (25+25))/100 + 1, = 4950 divided by 100 + 1, = 51 bars. For basic building the 4 number of bars is sufficient as per code. If a closer spacing of bars is required at the columns, as per Section 13. Bar schedule for Slab; Table 3 : Bar schedule for SlabArea of single bar = (3. 150m = 150 mm. As many of these requirements would need to be repeated in Chapters 3 through 14, placing such requirements in only one location eliminates code development coordination issues associated with the same requirement in multiple locations. Distribution bars are provided perpendicularly with the top of the main bar. The maximum anchor nominal diameter is 5 / 8 inch (16 mm). 6% of the gross wall area for Grade 60 or Grade 40 bars, respectively. 25. Width of the Slab = 2 m = 2000 mm. steel bars. Rebar steel will be calculated for the bending moments “Mx” and “My. 2) For main bars, maximum spacing is restricted to 3 times effective depth or 300. In the. Tayabji (1986) identified the following categories of dowelmillimetres and N represents the identification number of the bar/bars given consecutively. 3) or the distance of centre of gravity of the concentrated load from the nearer support (ci. 2). The flow rate, Q, in gallons per minute, can be computed as follows: Q (gpm) = 0. 318-19 Sections 7. 12% of cross-sectional area as distribution rebars as per. 2 d t kips in. Top & bottom clear cover = 50 mm. The minimum reinforcement spacing is based on maximum size of aggregates, so that concrete can be placed and compacted properly. The slab is. 2. 1 of IS 456:2000, the reinforcement in either direction ,in slabs shall not be less than 0. 3) For distribution bars, the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is smaller. L 1 = (2 x spacing of distribution bar) + (2 x the clear cover). As per IS code, the minimum grade of concrete for the design of a Pre-tensioned concrete structure is:-M20; M25; M40; M30;Cutting Length of Foundation Distribution Bar. Calculation for distribution bar: Bending moment for distribution. 1. 3. Step 1: – Calculate numbers of distribution rods. 6H, and 0. R4405. SECTION 5: CONCRETE STRUCTURES 5-5. 6. 2, also includes guidance on achieving enhanced aggregate interlock by continuing a small percentage of deformed reinforcement (0. 7 For temperature steel only, maximum spacing shall not exceed five times the slab thickness h nor 450. 960m. 3. How to calculate bar Bending Schedule for Slab? One way slab Reinforcement Detailing. 4 bars in the middle third of the footing depth. 5 bar is permitted to be located at either the top of the slab or bottom of the footing. dia. , addi-tional bonded shrinkage and temperature reinforcement conforming to 7. 7. 25 in. Calculation of effective depth. Diameter of main bar=10mm. d = Effective depth. 1 of IS 456), the maximum spacing is the. 1 Spread Box BeamsA. and the clear spacing between the bottom bars a = 60 mm. 7. As per ACI -The drop thickness should not be less than 100mm or (Thickness of slab)/4. LL = 6. 12. Design procedure. 3. (2× Spacing of distribution bar) + (2×25) = (2 x 150) + ( 2 x 25) = 350 mm . i = 100-yr. Radius = 2. 5. 7. Maximum spacing: The maximum spacing of main bars is limited to 3d or 300 mm (whichever. Only 2. Calculate the quantity of. unless otherwise noted in plans or specifications, camber all r. Bar Spacing. 5h ≤ 450mm (in areas of concentrated loads 3h ≤ 400mm) Where h is the thickness of. Basically slab is the horizontal member which is rests on the beam section. 3. The maximum spacing should be reduced by a factor of 0. Wall Load Per Running Meter. e. 6. Design of slab. Use M20 Concrete and 415 steel. 2. 2 or 8. . Weight of Distribution Bar=64/162. e min = (L/500) + (D/30) ≥ 20 mm. Cover block use 15 to 20mm. 3. 3-Main bar Bottom Area Given data. 1. Concrete Reinforcement January 2008 15-3. 5. Spacing of Main Reinforcement: The maximum spacing of bars shall not exceed. 0 8 #5 12 6 5 2 4. 7. Spacing of Main Reinforcement: The maximum spacing of bars shall not exceed. As = 0. Grade of concrete ƒck, Grade of Steel ƒy, Concrete cover, Clear long spam, Clear short spam, With of supporting beam, Live load, Floor finish load, The diameter of the main and distribution bar, and; Assume the. 6 𝑀𝑃𝑎. 67’ Weight of Distribution Bars = d 2 /52. MOM-X – Longitudinal moment, corresponding to which LONG. of Main bars = (3000)/150 + 1. Select the correct answer using the codes given below: A. You can design the two way slab using our android application. The slab edge insulation for heated slabs shall not be required to extend below the slab. 167, hence it is singly reinforced. How do bars spread out on slabs according to IS-Code & IF Code? The spacing between the parallel main reinforced bars for RCC is 300 mm (3D). c) Slab reinforcement percentage less than 0. critical section of the slab is just outside the outside edge of the beam supporting the slab. What should be maximum spacing of main and distribution bars in slab?We would like to show you a description here but the site won’t allow us. Bar cranking is the process of bending up the bottom steel bars in upward direction. 3). Roof drainage system (Adapted from the International Code Council). Diameter of the Main reinforcement bars = d m = 12mm. t + d Lsy. The diameter of the chair bar = d =12mm. 376Kgs For Floor slab -2 (One way slab) :-As per the above figure Floor slab -2 is a One way slab. ”Distribution bars are typically used in conjunction with main bars, and they are often spaced at regular intervals along the length of the main bar. Maximum spacing should not exceed the lesser of 20 x size of the smallest compression bar or the least lateral dimension of the column or 400 mm. 6. bars in two-way slabs. Bar Spacing: The lateral spacing of the flexural bars should not exceed 3 times the thickness h or 18 inches according to ACI code 7. Practical considerations of one-way slab • Spacing shall be between 150-200 mm (main bars) • Spacing shall be between 150-300 mm (distribution bars)Bar Bending Schedule for Two Way Slab. 4. • Maximum area of main steel in slab = 4% 𝑜𝑓 𝑏𝐷 (As per ACI). A s,min,reqd ≥ b*h*0. 13. 1. 2 and 26. 1 of IS 456:2000, the reinforcement in either direction ,in slabs shall not be less than 0. 785 x 16^2 = 200. 27. 10. What Is The Maximum Bar Spacing In Slab As Per IS-Code? In the case of the RCC slab, the maximum spacing between the two parallel main reinforcement bars should be 3D or 300 mm or whatever. Inclined length = 0. • The. If dowel placement deviates from the desired position, it is said to be misaligned. 15% of the total cross-sectional area of the slab (bD). 3 Required Strength 4-2. As per IS 456 : 2000, Minimum percentage of reinforcement: 0. The length of a distribution bar in east side is, = (17′-1½″) + 2 × 10″ = 18. iv) Detrmine Sapcing of bars at critical section based on designed value of Ast by selecting appropriate bar dia. BASIC THUMB RULE FOR RETAINING WALL DESIGN-Base slab thickness not less then 0 (H= Total height of retaining wall)The bottom part of the chair bar is called the leg of the chair bar. 3 Slabs-on-ground with turned-down footings. , Structural. Having <0. For columns exposed to weather or contact with the ground and embedded bars are No. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. A = roof area in square feet drained by the drainage system. 3. The following minimum limitations relating to various structural components shall be followed: Thickness of top flange : 100 mm. Since diameter of bar = 10 mm. Structural Design 1 - Design of Reinforced Concrete Structures REFERENCES/COURTESY 1) IS 456 : 2000 — Plain and reinforced concrete – Code of practice 2) S Unnikrishna pillai and. 13. , and if the lap length is taken as 50d, then. 5. 2. In case of mild steel, minimum reinforcement along either direction shall not be less than 0. The shear resistance in a R. 1 Answer. e. 42d. Refer to Section 5. 2 Maximum Distance between Bars in Tension. The clear cover will be 25 mm(Top or Bottom) and the thickness of the slab is 150 mm. C slabs. Load Distribution. The size of the stirrups should be chosen to avoid a closer spacing. 2. 40 cm;. 6. Take à l/d as 32 for HYSD bars . 5 In walls and one‐way slabs the maximum bar spacing shall not be more than three times the wall or slab thickness h nor 450 mm. 2 of IS 456 :2000 , the reinforcing bars shall not exceed 1/8 of theHow to Design Concrete Structures to Eurocode 2 - Chapter 7 : Flat slabs and Figure 6. If the maximum diameter for. Maximum Spacing between Stirrups . 25 x total length of bar. 225m. 76 Slab designation: CS1 Check if one-way or two-way slab 1 Slab is one way since it is catilever slab Minimum slab thickness min t = 69. Concrete floor slabs on grade are subjected to aIn steel reinforcement binding wire required is 8 kg per MT. of Main bars = (Width of Slab/Spacing) + 1. The no. 1905. Number of Required Bars Formula = (Length of slab / spacing) + 1. 12 % of the gross area if the HYSD bar (Fe415) is used. 11 bars and smaller, continuing reinforcement provides double the area required for flexure at. Collectors, Chords and ConnectionsIS Code. In this article, we will develop a Slab Design Example using the last version of ACI-318-19: “Building Code Requirements for Structural Concrete,” consisting of the modeling in SkyCiv of a Reinforced Concrete Low-Rise Building focusing on the comparison of software results and hand calculations by an accepted method by ACI: “The Direct Design Method for. b) Slab depth does not. 2. 5. anchorage to longitudinal bars and confinement of core concrete in resisting shear2. 896 x Total Length (where d is in # Nos. 975 KN)/ (39. 3 – When spacing of tendons exceeds 54 in. 2. IN Downloaded from Ktunotes. (1) Deformed steel bars will be overlapped for a distance of at least 24 bar diameters measured from the tip of one bar to the tip of the other bar. Minimum S&T reinforcement quantities required by ACI 350-01 and11. 5. C. 2. 5. 8. Spacing should not exceed smaller these two values. #IS456Explanation#SpacingofReinforcement#IESGATEWizIn this Video Part-45,detailed discussion of IS 456-2000 provisions of Spacing of Reinforcement Bars ha. 2 or 8. 2. Distribution Bar. C slabs. Lapping is not allowed for the bars having diameters more than 36 mm. (b) Slabs where Grade 60 deformed bars or welded-wire fabric (plain or deformed) are used: 0. Main Steel – 3d or 300 mm whichever is smaller; Distribution Reinforcement for Concrete Slab Design: The area of distribution reinforcement shall not be less than 0. 5. Leg of Chair= (2 * spacing of bottom main bar) + 50Plain bars———–10 mm Ø min dia Deformed bars—–8 mm Ø min dia; For Distribution bars: Plain bars———–6 mm Ø min dia Deformed bars—–6 mm Ø min dia; 4. f yk = 460 Mpa. 8. Adopt a clear cover of 20 mm and 8 mm diameter bars. 26. exposed to earth or weather. 3. 2 m), regardless of steel grade. For preparing the bar bending schedule according to the given data. the quality and basic shape of reinforcement bar shall be specified. The Indian Standard (IS) code for the preparation of steel bar bending schedules is IS 2502:1959. 1—Early-age concrete material strength development 4. According to Clauses 8. cm for 1 m width of slab where D is the overall depth of slab. Height of the footing (Thickness) = h =0. Number of Distribution Bars = Lx / spacing + 1 = 3000/150 + 1 = 21 nos. 4 mm. Step 1. No of main. 8 ACI 318 , Section 17. 2(5)4. ACI 360R, Section 6. to carry a uniform live load of 7500 Pa. 1123 mm. Number of Main Bar & Distribution Bar: First, we have to calculate the number of bar required for the slabs. Total Length of Distribution Bars = 19. The minimum spacing between the two bars can be about 50–75 mm. 1. 1. The Main. 5. Full bond Full bond h/2 Filler Figure 15:3: Contraction joint 15. The main conclusions can be summarized as follows: • The proposed method gives a good estimate for crack. 6. 5d = 5 * 130 = 650 mm. 8 of BS EN 1992-1-2 Eurocode 2: Design of concrete structures – Part 1-2: General rules – Structural fire design provides data which can be used to determine the thickness and cover requirement for concrete elements. 1. e. 11. e. A review of the behaviour and design of different types of beam-column joints in reinforced concrete moment resisting frame under seismic loading illustrates that design and detailing provisions for the joints in the current Indian seismic code, IS 13920 : 1993. 5 mm 2. 1 for minimum thickness of non-prestressed two-way slabs without interior beams is revised to include Grade 550. The Distribution bars will be 8 mm in diameter with 125 mm c/c spacing. vapor retarders - some times referred to as vapor barriers, insulation, etc. Area of Steel 'Ast req. 10mm Ø hor. 2 SlabsContinuous OverSupports 24. are called concrete. In general we use 5 inch (125mm) thick slab, if thickness of slab is 125mm,then maximum diameter of bar used in. 096 square inches per foot (or #4 bars at 18 inches center to center to meet ACI criteria, As = 0. 6 = 17. Now, we will calculate the length of the three parts of the chair bar separately. 15m. Nos of Bars =. 6. 7. These were developed for slabs of “ordinary” proportions supporting gravity loads, and they may not be sufficient to intercept potential punching shear cracks in thick transfer slabs, podium slabs, and mat foundations. 6m. For concrete cast against and permanently. 5 in Y-axis Distribution area 3. 0018. of main bars = Lx/Spacing + 1 = 5000/150 = 34. 896 x Total Length (where d is in # Nos. bar due to its non-availability. Top and bottom clear cover of slab is 20 mm. Check for Cracking. 2 to read as follows:Historically, this level of precompression was found to enhance the performance of punching shear in two-way flat slabs based on tests conducted with this level of precompression. slabs is Thickness of slab/8 14. Provided to resist the shear stress and cracks. 5φVc except for the following cases: A. 6. b. On the bigger side, distribution bars are supplied, however, they will not assist in bearing any weight. Note * rationalise centre of bars in column strips T2 and B2 to 175 mm centres to suit punching shear links. 3. 3. 1. The main bars will be 12 mm in diameter @100 mm c/c spacing. 3. t + d Lsy. Provided at the top of the slab. 900 m. TRANS REINF - Reinforcement required along the transverse direction ( along local Y axis of the plates ). Use #4 bars at 25-inch spacings center to center each way, As = 0. 3. 11in2) Spacing = As 0. According to Clauses 8. Estimation of the joint movement, is therefore, theTwo-Way Slabs 6 b- Distribution of the total factored static moment to negative and positive moments: I. M =.