Check for Cracking. 2(5)4. 3, 1) The horizontal distance between parallel main reinforcement bars shall not be more than. 5. 14 m, and 10. ) = 200. This spacing should be reduced by a factor of 0. 14. 6. 9 Factored loads Factored dead load = 3. 5. 3 Slabs-on-ground with turned-down footings. Minimum number of bars. Weight of Distribution Bar= d²/162. 140 M. 7. Design of slab. C. d = Effective depth. 5. 2 SlabsContinuous OverSupports 24. According to it, if a slab rests on its support freely, the span length may be taken as equal to the clear span plus the depth of the slab but need not exceed the distance between the centers of supports. is more that the diameters used here. where. The size and type of rebar used in concrete slab footings will depend on the specific requirements of your project, including the size of the slab, the load it will support, and local building codes. 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. Weight of Distribution Bar=64/162. 3(d) and 17. Lap length diameter: When we extend the top bar of the column from the bottom bar, having an unequal diameter, then the lap length is calculated for the smaller dia. 8. B. In Flat plate slab the, distribution bars are arranged in one direction at Top of main bar (in longer span). 1. BS EN 1992–1–1 section 6. 7. Given the radius of relative stiffness of 90 cm. 5. Thickness of Slab = 0. 3. Minimum Bar SpacingAs per AASHTO LRFD, section 5. C. 2, also includes guidance on achieving enhanced aggregate interlock by continuing a small percentage of deformed reinforcement (0. The need for a com-posite slab roof may also affect architectural and MEP details, hence the need for a decision early in the design process. 2—Construction load factorsThe diameter of the main bar should not be less than 8mm for the HYSD bar and 10mm for plain bars. Always main bar use in shorter span. Provided at the top of the slab. 6. is the strength reduction factor as specified by table 21. For slabs less than 200 mm thick the following maximum spacing rules apply: For the principal reinforcement: 3h but not more than 400 mm. 10mm Ø hor. b. The minimum yield stress of main reinforcement bars and shear links in the structural elements forming the SS, S/C SS or scissor S/C SS or NS shall be minimum 500 N/mm2. Distribution Bar. If the maximum diameter for slab thickness is 75 mm, so the diameter of reinforcing bars should be 8 mm. 1-1 and its accompanying notes, except as modified herein. 6. For a given area of tension steel areas, the distribution of steel reinforcement affects. Anchor bolts are embedded into concrete a minimum of 7 inches (178 mm). - M. 1 QA Stockist’s certification of steel reinforcing bars 25 4. The new formulas are more complex and consider more parameters, such as bridge length and. Flexural tension reinforcement shall not be terminated in a tension zone unless (a), (b), or (c) is satisfied: (a) Vu ≤ (2/3)ϕVn at the cutoff point. it's a tool to maintain the spacing between two separate layers of slabs, footing etc. f. 7. 1—Minimum flexural reinforcement in nonprestressed slabs 8. 0104 Ai. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. This type of reinforcement is convenient for modeling layers of reinforcement over a portion or the entire slab area. So, provide spacing of distribution bar equal to. 1. 9. of Main bars = (Width of Slab/Spacing) + 1. 8. Weight of Main Bar = (102/163) x 126. 2 Specific requirements for QA Stockists 26 4. The spacing < 300mm and <3*d as per Cl. Slab Thickness = 150 mm. Heavy loads. 25 kN/m 2. 4. 4. 3 of the Eurocode or Chapter 2, originally published as. The spacing or c/c distance of distribution bars shall not exceed the following. of bars = { (L or w – concrete cover for both sides) ÷ spacing} +1 Equation 8. What Is The Maximum Bar Spacing In Reinforced Beams According To IS 456? Normally this. For concrete cast against and permanently. Distribution bar = 8mm@150mm c/c. Unit weight of concrete = 25 kN/m 3. A minimum of three bars evenly placed in the lap length is required. 3 through the column, at least two post-tensioned tendons or two bonded bottom bars or wires in each direction shall pass through the lifting collar as close to the column as practicable. Lap length 50d = 50 × 16mm = 800mm. One Way Slab Bar Bending Schedule Calculation. For distribution bars (cl. 3 through the column, at least two post-tensioned tendons or two bonded bottom bars or wires in each direction shall pass through the lifting collar as close to the column as practicable. 2 (8) Beams: the maximum transverse spacing of the legs in a series of shear links s t,max; 9. 6. total angular change of tendon profile from tendon jacking end to point under considerations, radians. 3 m) is either 0. 11in2) Spacing = As 0. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. For distribution bars, the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is smaller. For structural slabs of uniform thickness the minimum area of tensile reinforcement in the direction of the span is: For US-units: IF Grade 40 to 50 deformed bars are used. For longitudinal bars in columns of size more than 200 mm. Consider the ACI 318-14 code according to which the Ø is the strength reduction factor as specified in table 21. of Main bars = (3000)/150 + 1. e. cm. The quandary with composite slab roofs is that a composite slab provides higher shear strength, but it also adds mass to the system thereby increasing seismic forces. Assume 𝑓𝑐′ = 27. 3. k’ = 0. BS EN 1992–1–1 section 7. Distribution Bar. W = 3. 3 Required Strength 4-2. Fig. Every alternate bar is cranked up to 0. 9. 50 8. Here we have to calculate the number of main bar and distribution bar. Given, Cranked bars or Main bar of diameter 16 mm and center to center spacing 150 mm. 3. 0018. Concrete cover = 25 mm. 5 The lateral spacing of temperature and shrinkage reinforcement should not be placed farther apart than 5 times the slab thickness or 18 inches according to ACI code 7. Now assume diameter of bars and calculate spacing between bars. e. Distribution Bars= (Total length of the slab – 2 x clear cover)/center to center spacing of the bars + 1; Distribution Bars = (2000- 2 x 25) /125 +1; Distribution Bars = 16. The reinforcing bars must extend into the slab beyond the critical section for a required length. 002 times the gross cross-sectional area of the footing. e. For main bars, maximum spacing is restricted to 3 times effective depth or 300 mm whichever is smaller. 34 kg Section 2-1. 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. 3. Provided at the top of the slab. 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. Waist slab Bar Bending Schedule. 200= 6. That is 11′. Diameter of the Main reinforcement bars = d m = 12mm. 5. 2). 133 square inches per foot). The maximum diameter of the reinforcement bars in RCC slab is should not greater than (1/8) of slab thickness as per IS code provision standards. however with a maximum spacing of 4. Cryptocritical section of the slab is just outside the outside edge of the beam supporting the slab. However,. April 2, 2023 May 25,. The center of the dowel bar should be below the joint. 3. 60 kN/m. 8. 64 2 )/8 = 23. 2. The Clear cover will be 25 mm (Top or Bottom) and the thickness of the slab will be 150 mm. 1 of IS 456:2000, the reinforcement in either direction ,in slabs shall not be less than 0. 1 given below by the ACI 318-14 code. 7. The slab is. 2. 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. Spacing =150mm. The slab is not. Spacing Requirements. 10 cm; 12 cm; 14. 3. D = Height of the bending bar. The thickness of Slab – 150 mm. 4. 3 Aggregates 5. 285+150. the total length of the leg is 2×spacing +50. Modify ACI 318 Sections 17. Minimum S&T reinforcement quantities required by ACI 350-01 and As per IS 456:2000, in rcc slab, maximum diameter of main bar and distribution bar should not exceed 1/8th thickness of slab. Total Load on Slab (Dead Load + Live Load +Wind Load + Self-Weight) Besides this above loading, the columns are also subjected to bending moments that have to be considered in the final design. 133 square inches per foot). The Distribution bars will be 8 mm in diameter with 125 mm c/c spacing. Q) Calculate the quantity and weight of steel rod in a one-way slab having length 6 m, width 2. 347. How to Design Concrete Structures to Eurocode 2 - Chapter 2: Getting started. So may be in this case, chair may be required more. This method is applicable to straight and right (i. × c/c distance between the top distribution bar) + (extra length on either side of the top distribution bar)]Calculate the nos’ of facet rebar. The slab is. 2 Effective Length ofCompression Members 25. 54 * 1000 / 180 = 436. 1 — Area of shrinkage and temperature reinforcement shall provide at least the following ratios of reinforcement area to gross concrete area, but not less than 0. The diameter of the main bar is 12 mm in diameter with 100 mm c/c spacing and the diameter of the distribution bar is 8 mm with 130mm c/c spacing. 2. 04𝑥1000 𝑆= = = 272. 3. The diameter of the chair bar should not be less than 12 mm. 0018 times the slab's gross area, but the maximum spacing of the bars differs. For distribution bars, the maximum spacing is specified as 5 times the effective depth. AS3600-2009 P P Lsy. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. 5. 7. 24. The slab is not. the quality and basic shape of reinforcement bar shall be specified. Effective depth=d provided =120-20-4= 96 mm. 4 bars in the middle third of the footing depth. 12. f. TRANS REINF - Reinforcement required along the transverse direction ( along local Y axis of the plates ). The distribution bars should not be under 8 mm in a diameter or not be over 1/8 of the thickness of the R. Special surface finishes, including coatings. Minimum S&T reinforcement quantities required by ACI 350-01 and11. bars should be arranged as distribution bars and are provided at 30 cm centres at the top of the. 1 Definitions 25. ( IS: 456-2000 ). 10. 1 and 24. 2. 2. 2. Main Steel – 3d or 300 mm whichever is smaller. The minimum spacing between the two bars can be about 50–75 mm. As = 0. 2. R403. Step 3 – Top Distribution. 960 x 16 =. 2 As per NSCP 2015, a minimum shear reinforcement in concrete design shall be provided in all regions where Vu > 0. 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. 7. 6. 8. Total No’s of Distribution Bars = (Total layers of Dist Bars in Walls are 4) = 10 x 4 = 40 No’s Total Length of Distribution Bars = Cut Length x No’s of Bars. Continuously at structurally connected roof and floor levels and at the top of walls. The cross‐sectional area of one N28 bar is As = 620 mm2 and with N12 stirrups at 150 mm centres, Atr = 110 mm2. Minimum number of reinforcing bars required. No of bars = (opp length/spacing) + 1. bar. If shear reinforcement is required for in-plane strength, spacing of longitudinal reinforcement shall not exceed l w /3. The Department of Civil Engineering at IIT Kanpur is producing since 1961, high quality technical manpower needed by industry, R&D organizations, and academic institutions. 15m. The flow rate, Q, in gallons per minute, can be computed as follows: Q (gpm) = 0. 2Dead Load + 1. of Main bars = 20 + 1 = 21 Nos. The AASHTO-LFD formulas are based on the girder spacing only and are usually presented as S/D, where S is the spacing and D is a constant based on the bridge type. 7. 1 or the bottom bars required by 8. 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. 6 For two‐way slabs, maximum spacing of bars shall not exceed two times the slab thickness h nor 450 mm. Calculated area; 5 x d; 450mm; Diameter of bars. 2. 3. Minimum Reinforcement Ratio in Slabs. 5. 0m from the fixed end. No of Bars/m 2 = Factored Load / Pcr. This spacing should be reduced by a factor of 0. 5bw and 600 mm B. Crack Control – when crack widths are not checked by calculations No Further Checked Required. thick slab, the maximum joint spacing should be limited to 12 to 15 ft. 9 m = 3. 2. 26. 2. What are the distribution bars in a slab? The reinforcement bars that are placed above the main bar in a one-way slab, to distribute the superimposed load to the main bar are called distribution bars. Development Length (Ld) = 40d. C. Step 1. 6. àIn case the thickness of slab is 120mm, the height of bent bar should be 60mm. 2. In two way slab, distribution bars are provided in both sides of slab. Bar Spacing. Distribution Bars are used to hold the slabs on either way and to resist the cracks. The span requirement for the slabs is given by ACI Code 8. 2. For longitudinal bars in slabs. The length of a distribution bar in east side is, = (17′-1½″) + 2 × 10″ = 18. Sub-slab details (i. C. An interaction between steel requirements for bending in the slab and longitudinal shear has to be considered. Figure-2: Distribution or shrinkage and Temperature Reinforcement Bars in One-way Concrete Slab. = 27. The diameter of the chair bar = d =12mm. 8 ACI 318 , Section 17. 6. 2. Distribution Bar. 3. 2, with “S” assumed to be equal to the length between negative moment design sections. 1 for minimum thickness of non-prestressed two-way slabs without interior beams is revised to include Grade 550. 3(1) of EC2 for slabs not exceeding 200mm in overall depth and not subjected to significant axial tension the maximum limit on centre to centre bar spacing is governed by clause 9. 8. The distribution bars’ primary function is evenly distributing the load across the slab. 1-4. Main Steel – 3d or 300 mm whichever is smaller. Total Length of Distribution Bars = 19. Distribution bars of diameter 12 mm and center to center spacing 150 mmm. 2 Spacing s of transverse bars in precast walls shall not exceed the. b) For design of distribution bar/Transverse bar. Length of the Slab = 5 m = 5000 mm. Opposite length of bar = 2950. 12D Sq. Given the radius of relative stiffness of 90 cm. 225m. Distribution steel: 0. 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. 12. (b) Slabs where Grade 60 deformed bars or welded-wire fabric (plain or deformed) are used: 0. 2—Construction load factorsThe diameter of the main bar should not be less than 8mm for the HYSD bar and 10mm for plain bars. 7. 26. 8. 3(1) of IS 456, is the lesser of 3(135) and 300 mm. 1. #IS456Explanation#SpacingofReinforcement#IESGATEWizIn this Video Part-45,detailed discussion of IS 456-2000 provisions of Spacing of Reinforcement Bars ha. the constant value of 50. Radius = 2. To calculate: Spacing of replaced 12mm. 4 bars in the middle third of the footing depth. 5, the lateral spacing of the. 6m . Main Bars and Distribution Bars in Slab and Their Function. member has shallow depth of less than 200 mm (ex. 2 Use Φ12 bar c/c 250mm 2. Main Reinforcement bars are placed in shorter direction and Distribution bars placed in longer span direction. 5% steel (continually reinforced) as described in Section 8. continuous slab – code coefficients-. Spacing of 10mm bar = S1 =150 c/c. Distribution bars placed on top of the main bar. Ensure a minimum number of bars in a square column is 4 and in a circular column, 6. / 0. What should be maximum spacing of main and distribution bars in slab? 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. 150m = 150 mm. , 300 mm. 11. 3. Transverse joint spacing should not exceed 125% to 150% of the longitudinal joint spacing. The distribution bars’ primary function is evenly distributing the load across the slab. 785 x d^2 = 0. Step Find the length of the dowel bar embedded in slab by equating Eq. 4. This is also. The main reinforcement of an RC slab consists of 10 mm bars at 10 cm spacing. 3. joint spacing greater than 50 ft (15. per 1 m 2. 7. Spacing required = Area of 1 bar x 1000 / (Ast req. You just enter your information in the yellow colour box for the design of two way slab excel sheet as per is 456 such as. 11. Distribution of Main Bars. Conclusion. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. The Department offers B. The maximum reinforcement ratio for columns is 0. In case of HYSD bars, minimum reinforcement along either direction shall not be. 1. Unit weight of concrete = 25 kN/m 3. purchase orders, drawings, or per diems shall be done at the risk of those making such references or quotation. Step 1. 3) or the breadth ofthe rectangular beam or slab or the breadth of the rib in case of flanged beam (ci. The design method is followed as per Annexure D of IS 456:2000. If a closer spacing of bars is required at the columns, as per Section 13. 3 only and there is no need to perform specific checks on the bar spacings to control cracking. Inclined length = 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. 1. 2. 85MPa) was added as a code requirement. Use M20 Concrete and 415 steel. spacing of 18” d) Choose bars: For square footings use the same size and number of bars uniformly spaced in each direction (ACI 13. 4 Splices in reinforcement. slab should not exceed three times the effective depth of the slab or 450 mm whichever is smaller. 12. 5 mm 2. 3 b) 1). Workmanship and jobsite conditions. As per ACI Code, In slab, minimum reinforcement shall be 0. In general we use 5 inch (125mm) thick slab, if thickness of slab is 125mm,then maximum diameter of bar used in. 6m. 3. Bar Spacing According to ACI Code 7. 300mm. One Way Slab Reinforcement Detail. Given, Length of longer span = 5000 mm. Distribution bars are provided perpendicularly with the top of the main bar.