Top & bottom clear cover = 50 mm. Total wt of Bars = 150. Mild reinforcing bars shall have minimum clear spacing of at least 2 in. 2. No of bars = 41 nos. B. , B. Bar Bending Schedule Of Slab (Two Way) Ly/Lx = Longer span/Shorter span = 5000/3000 = 1. The minimum spacing between the two bars can be about 50–75 mm. The main reinforcement of an RC slab consists of 10 mm bars at 10 cm spacing. Minimum number of reinforcing bars. 13. where. Compute number of steel bars. and 𝑓𝑦 = 276 𝑀𝑃𝑎 for main and temperature bars. The size of the stirrups should be chosen to avoid a closer spacing. Lower part bar will be worked by maintaining cover with spacer. 7. 5. 5 times effective depth d. 3. 8. Weight of rod per meter length = d 2 /162 where. 14. Provided at the top of the slab. First, find number of rods required for main reinforcement and distribution. 7. 5, the lateral spacing of the. 14 x 5 x 5 = 78. 9. Distribution Reinforcement bar: No of bars = total span/spacing = 2960 mm/200 mm = 15. 8. 3. DESIGN OF SLAB: Design of typical Floor Slab: We have thickness of slab as 130 mm. Some discussion to decide about max spacing: AS per IS 456: Maximum spacing for bars in beams is 180mm for Fe415 grade and 150mm for Fe 500 grade reinf. 5 inches, and the transverse bars must be fully developed in grouted masonry at the point where they cross the lapped reinforcement. Ensure that the return bars at the edge of the slab are a minimum of ¼ (15%) of the length of the adjoining span. 150m = 150 mm. R403. ([DPSOH ± 'HWHUPLQDWLRQ RI Seismic Forces: Diaphragms of %XLOGLQJ Chapter 4 One-way Slabs 4. LL = 6. e. thick slab, the maximum joint spacing should be limited to 12 to 15 ft. 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. For rectangular footings bars in long direction should be uniformly spaced. 2 of IS 456) shall not exceed 140/8 = 17 mm is also satisfied with the bar diameters selected here. As per IS 456: 2000, Cl. The spacing of the chair bars depends on several factors which are listed below: – Diameter of the bar used in making a chair. Spacing = 150mm c/c as per given details = (6000/150) + 1. 6 bars shall not be used for S1 and S2 bars due to interference with strands and other reinforcement. Earth Pressure intensity (q) = N/A prov = (18765. Reading time: 2 minutes. Head of Chair: Length of head = (2 * spacing of distribution bar) + (2 * 50) = (2 * 150) + (2 * 50) = 400mm. So, we need to calculate the value of ‘D’. For Min Steel: 3d ——— Where. The maximum spacing of main bars, as given in cl. 090 square inches per foot of slab width, required each way. Weight of Distribution Bar= (8)²/162. Consider the ACI 318-14 code according to which the Ø is the strength reduction factor as specified in table 21. It brings economy to the design of. Spacing of Main reinforcement bars = s m = 150mm c/c. 3. 0018 times the slab's gross area, but the maximum spacing of the bars differs. 6. three times the effective depth of solid slab or; 300 mm; whichever is smaller. 75 m. The direction of the main bars (T1 and B1) in a flat slab system depends on various design factors such as the span length, load distribution, structural efficiency, and code requirements. One Way Slab Bar Bending Schedule Calculation. Refer to "Determination of Bonded vs. (Main Bar & Distribution Bar Difference) Top and Bottom Clear Cover is 25 mm. According to ACI Code 7. Self-weight of the slab = 3. Spacing Requirements. As per clause 26. Slab concrete ratio less than M15 grade. 3. Design ProcedureAllowable clear spacing of bars = 3d = 3(170) = 510 mm Actual clear spacing = 300 – 10 = 290 mm < 3d → ok Figure 3. Considering M20 grade of concrete and Fe 500 steel of diameter of 10 mm. 2. This is also satisfied for all the bars. 78′ Say, 19′. = 175 mm Last perimeter, from column face, min. 347. April 2, 2023 May 25,. Total length of Foundation Distribution bar =No’s of bar x cutting length. however with a maximum spacing of 4. 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. Spacing = 150mm c/c as per given details = (2950/150) + 1 = 20. 5. Note that required A s must be furnished in each direction. Rebar steel will be calculated for the bending moments “Mx” and “My. To calculate: Spacing of replaced 12mm. Cryptocritical section of the slab is just outside the outside edge of the beam supporting the slab. 50 8. 2. f yk = 460 Mpa. Waist slab Bar Bending Schedule. , 1-hr. Slabs - - - maximum spacing is 3*deff or 300mm whichever less side ) of the deformed bar ( see Note ) NOTE - In accordance with IS : 1139-1966. k’ = 0. So, provide spacing of. Is 1200 Important Point Part-1; IS Code for Civil Engineer [Q&a]. Loads which consist of any on e of the following: moving live loads exceeding a. 3. Step 1- Calculation of Numbers of Bars. Solving for the Number of Reinforcement Chair required per square meter: Since the chair reinforcements support only the top layer, then we will consider the weight of top mesh reinforcement as dead load. Cover block use 15 to 20mm. 4 and shall have a total area of not less than 0. 4. Reinforcement Cover The minimum cover to outside of main bars shall not be less than the following: 15 mm and; Diameter of the main bar. 4. than that calculated as per Sections 12 and/or 16 (whichever is higher) of IRC:112. This is plotted against the overall fire rating of the structure that is being designed. Maximum spacing of bars for slabs • Main bars: 3h ≤ 400mm (in areas of concentrated loads 2h ≤ 250mm) • Secondary bars: 3. Consider 28 Nos. 1: The prime functional requirement of a joint is to cater for movements with very low resistance or with no resistance at all. (i) The pitch of the main tensile bars in R. The maximum spacing of bars shall not exceed. Given the radius of relative stiffness of 90 cm. 1 for minimum thickness of non-prestressed two-way slabs without interior beams is revised to include Grade 550. Diameter of Distribution Reinforcement Bars = d d =12mm. The slab requires 51 main bars. Concrete cover = 25 mm. 2 As per NSCP 2015, a minimum shear reinforcement in concrete design shall be provided in all regions where Vu > 0. 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. Minimum Reinforcement Ratio in Uniform Footing. 7. 5. Fig. Abstract. 4. 3. Distribution bars are placed on the top of the. 1. 1. Only 2. D = Height of the bending bar. Provided at the bottom of the slab. 3 of the Eurocode or Chapter 2, originally published as. 15%of gross cross-sectional area if plain bars are used and 0. 2 or 8. 3. The minimum percentage of reinforcement is 0. Dual degree in Civil Engineering, and M. 3 m) is either 0. Actual variety of 1 sides rebar =Number of main bar – rebar of the middle. 5. Instead, to comply with ACI minimum reinforcing ratio and bar spacing requirements, slabs from 4 to 7 inches thick should have at least #4 bars at 12 inches on centers; closer spacing or larger bar sizes are needed for thicker slabs. total angular change of tendon profile from tendon jacking end to point under considerations, radians. Distribution steel –5d or 450 mm. Use M20 Concrete and 415 steel. 8. 18D sq. 3. 6H to 0. 5 Spacing limits and concrete cover for reinforcement shall be shown on the design drawings. Unbonded Cross Sections" for discussion. In both cases, the minimum bar areas are equal to 0. Ex. The span requirement for the slabs is given by ACI Code 8. 12% of cross-sectional area as distribution rebars as per. cm. Note: When ACI 318-19 is selected, an additional size effect factor λs is added in the above equations, λs is a function of effective depth of the slab d, and is calculated per Equation (22. C. Provide main reinforcement of 10 mm diameter bars at 120 mm c/c. So No, of 8 mm Steel bar = 3. Where a slab on ground is cast monolithically with the footing, one No. 1. spacing of reinforcing bars (cls. bars are used as distribution bars and are placed at 30 cm centres at the top of the bottom bars. For distribution bars the maximum spacing is specified as 5 times the effective depth or 450 mm. The slab is. 2 or 8. 6. One Way Slab Bar Bending Schedule Calculation. Distribution Bar. Maximum size of bars in slabs As per clause 26. 2 For one-way shallow foundations, two-way isolated footings, or two-way combined. 5. 6 = 17. The spacing of distribution bar should not be greater than 5 times the effective thickness of slab or 450mm whichever is smaller. 13. Diameter of the Main reinforcement bars = d m = 12mm. 5 m as per IRC. Tech degree in Civil Engineering with six specializations, i. Beams = Self Weight per running meter. Joist system relative dimensions, slab thickness, rib width and spacing between ribs are specified in ACI 318-05, Section 8. The cross‐sectional area of one N28 bar is As = 620 mm2 and with N12 stirrups at 150 mm centres, Atr = 110 mm2. 140 M. Suppose we have a one way slab,which having a length 5 m or width 2 m (clear span). Check spacing of bars. 5. Number of Main Bar & Distribution Bar: First, we have to calculate the number of bar required for the slabs. Note: The minimum clear spacing of bars is not kept less than 75 mm (Preferably 100 mm) though code do not recommend any value. tangential spacing of legs of links, st max. as indicated in the table. bars at 400 mm o. 14 x r x r) = 3. Five times the effective depth of slab, and; 45 cm. For Edge Spans : Static Mom. The distribution bars provide the following functions in slab construction: 1. The distribution bars provide the following functions in slab construction: 1. Calculation of no of bars required in slab reinforcement Number of bars = length of lab/spacing +1. 2. = 27. Number of Distribution Bars = Lx / spacing + 1 = 3000/150 + 1 = 21 nos. The distribution bars should not be under 8 mm in a diameter or not be over 1/8 of the thickness of the R. The slab is not. Diameter of top and bottom main bars = 20 mm. Step 2: Preliminary dimensioning. 1. For footings that exceed 8 inches (203 mm) in thickness, a minimum of one bar shall be provided at the top and bottom of the footing. Section 8. , Chapter 12 c c = clear cover of reinforcement, in. 3(d) and 17. 3) or the breadth ofthe rectangular beam or slab or the breadth of the rib in case of flanged beam (ci. Refer to Section 5. R4405. 12% of the total cross sectional area , when HYSD bars Fe415 are used. 5. cb = smaller of (a) the distance from center of a bar or wire to nearest concrete surface, and (b) one-half the center-to-center spacing of bars or wires being developed, in. the maximum spacing between two secondary parallel bars in case of RCC Slab shall be 5d or 450 mm or whichever is less. Joints are provided in concrete pavements to control. Unit weight for feet per metre = (D2/ 533). and floor finishes 1 KN per meter square. The Clear. 3. Concrete Reinforcement January 2008 15-3. 9 for flat slabs with drops. Collectors, Chords and ConnectionsIS Code. 3. 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. #IScodes #Concrete #Concretetechnology Recent & Related Videos Concrete. 8 ACI 318 , Section 17. If a closer spacing of bars is required at the columns, as per Section 13. 1 or the bottom bars required by 8. 4, Chapter 10 ct = distance from the interior face of the column to the slab edge measured parallel to c1. 3 Factored live load = 3. c. e. Adequacy of curing. The thickness of Slab – 150 mm. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. 24. ? 1. 96 sq mm. Total Length of Distribution Bars = 19. Spacing =150mm. 67’ Weight of Distribution Bars = d 2 /52. The spacing between longitudinal reinforcement of the column should be the greatest of the following: 4 cm; 1. Full bond Full bond h/2 Filler Figure 15:3: Contraction joint 15. What are the different functions of distribution bars in concrete . (c) Distribution. For concrete cast against and permanently. 1. IF Grade 50 to 60 deformed bars or welted wire reinforcement are used9. , addi-tional bonded shrinkage and temperature reinforcement conforming to 7. 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. Step 1 – Find out the Total Number of Main Bars & Distribution Bars. 2) For main bars, maximum spacing is restricted to 3 times effective depth or 300 mm whichever is smaller. 4—Construction load distribution 3. with a banded tendon distribution is achieved without this. No of Bars/m 2 = Factored Load / Pcr. Step #1 – Bar Numbers. Distribution of Main Bars. Sub-Grade and. This value is commonly used in design today as the minimum. 3 Slabs-on-ground with turned-down footings. Maximum spacing: The maximum spacing of main bars is limited to 3d or 300 mm (whichever. Minimum Reinforcement Ratio in Slabs. Design Guide on the ACI 318 Building Code Requirements for Structural Concrete. No. 3 Slabs-on-ground with turned-down footings. Distribution steel –5d or 450 mm whichever is smaller Where, ‘d’ is the effective depth of slab. 1 (2) states that, distribution should minimum 20% of the main reinforcement. Factor affecting spacing of chair bars. 3. 3. Each alternate bar is cranked up to 0. 9, page 341. 6. Sawcut Joints A typical SOG includes three different types of joints, described in detail in ACI 360R Chapter 5. What is the maximum spacing of bars in a flat slab? The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. FAQ . 5 h Finding out bar spacing: Let us chose # 3 bar (0. Tayabji (1986) identified the following categories of dowelmillimetres and N represents the identification number of the bar/bars given consecutively. 3 Design of the slab (per meter strip) Bending moment on the slab is maximum at the face of the column (in this case at the face of the upstand beams) (clause 3. Clear Cover = 20 mm. The wires or bars will be lapped as follows. 6. Placed at a longer. Main bar = 12mm@150mm c/c. Reinforce concrete for a 5-inch thick concrete slab: For a 5-inch thick slab, #4 (1/2-inch diameter) rebar is commonly used. 8. 17 The design of one-way slab is simple and can be carried out easily. 1. If a closer spacing of bars is required at the columns, as per Section 13. 6H to 0. , 300 mm. The minimum percentage of reinforcement is 0. Figure: Contraction joint;. 2 or 8. 6—Factors affecting the construction load distribution 3. 4. The larger the diameter of the bar, the more the spacing is, and vice versa. No. × c/c distance between the top distribution bar) + (extra length on either side of the top distribution bar)]Calculate the nos’ of facet rebar. It is mainly to prevent upward bending moment near the joint. 5 m. 12 % of the gross area if the HYSD bar (Fe415) is used. 2, with “S” assumed to be equal to the length between negative moment design sections. Now assume diameter of bars and calculate spacing between bars. SECTION 5: CONCRETE STRUCTURES 5-5. ACI 7. 7. 3d or 300 mm whichever is smaller for main steel. Always main bar use in shorter span. No of Bars/m 2 = Factored Load / Pcr. 12. 230m. If the maximum diameter for slab thickness is 75 mm, so the diameter of reinforcing bars should be 8 mm. 6. A minimum of three bars evenly placed in the lap length is required. The following details are obtained from the figure-2: Length of Footing = X = 2m. 0020. 5 specifies that Spacing ≤ 3h or 18 in, whichever is smaller but > 1. 2. 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. 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. >EAST side. Proportioning of flat slabs: As per cl. of bars= (Slab length (L)/spacing)+1 Equation 1. 4. The length of a distribution bar in east side is, = (17′-1½″) + 2 × 10″ = 18. cm for 1 m width of slab where D is the overall depth of slab. 5. MOM-X – Longitudinal moment, corresponding to which LONG. 2 and 9. 25 8 #5 12 6 6 2 4. spacing of 18” d) Choose bars: For square footings use the same size and number of bars uniformly spaced in each direction (ACI 13. t 12mm stirrups at 150mm ctrs Two terminated bars A A Elevation Section A-A Lsy. Important Point: As per IS 456:2000, the limit on minimum reinforcement along either direction has been specified. Step Find the length of the dowel bar embedded in slab by equating Eq. Bar schedule for Slab; Table 3 : Bar schedule for SlabArea of single bar = (3. As per IS 456: 2000, Cl. In. 4 MoVEMEntS And rotAtIonS: 4. What Is Bar Bending Schedule | Preparation as Per Bs 4466 | Tolerances as Per Bs 4466; Disadvantages of Dowel Bar. 2. M255M/M 255 (2019) Standard Specification for Steel Bars, Carbon, Hot-Wrought, Special Quality, Mechanical Properties M 334M/334 (2017) Standard Specification for Uncoated, Corrosion-Resistant, Deformed and Plain Chromium Alloy, Billet-Steel Bars for Concrete Reinforcement and Dowels T 253-02 (2016) Standard Method of Test for Coated Dowel. Figure-2: Distribution or shrinkage and Temperature Reinforcement Bars in One-way Concrete Slab. Area of Steel 'Ast req. , Structural. shall be the lesser of (i) five times the effective depth, or (ii) 450 mm. Diameter of top and bottom distribution bars = 16 mm. , nonskewed) bridges only. 0104 Ai. 2and3 C. Development length = 40d. 3 only and there is no need to perform specific checks on the bar spacings to control cracking. C. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. For instance, the ACI 318-19 specifies minimum slab thickness that satisfies deflection. 4: Two-way slabs having multiple spans; The purpose of the code is to design the total amount of reinforcement steel rebar into principal directions in the slab system.