Length of waist slab= L. for exterior walls or 30 in. 2) For main bars, maximum spacing is restricted to 3 times effective depth or 300. however with a maximum spacing of 4. 3. #IScodes #Concrete #Concretetechnology Recent & Related Videos Concrete. Provided at the bottom of the slab. 3 of IS 456). The maximum spacing of bars shall not exceed. 5 bars required by 14. Code of practice for plain and reinforced concrete ( third revision ) Specification for high strength deformed steel bars and wires for concrete reinforcement ( t&d revision ) Criteria for earthquake design of structures (fourth revision ). Basically slab is the horizontal member which is rests on the beam section. 66 < 2. Maximum spacing of bars for slabs • Main bars: 3h ≤ 400mm (in areas of concentrated loads 2h ≤ 250mm) • Secondary bars: 3. The design of a one-way slab can be done by using the Indian standard code. The length of a distribution bar in east side is, = (17′-1½″) + 2 × 10″ = 18. Main Steel – 3d or 300 mm whichever is smaller; Distribution Reinforcement for. , Chapter 12 c c = clear cover of reinforcement, in. The code itself suggests that the diameters can be #3, #4 and #5. 3. Given the radius of relative stiffness of 90 cm. 3. 3. 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. bars in two-way slabs. 5:3) 2) centering and shuttering for slab 3) Weight of 12mm Φ bars 4) Weight of 6 mm Φ distribution steel bars 5) Abstract for approximate estimate 6) Cement, sand, Aggregate for slab 7) Percentage steel in slab 8) Cost of slab per m. 5. 5. Refer to "Determination of Bonded vs. 2. Maximum spacing: The maximum spacing of main bars is limited to 3d or 300 mm (whichever. R403. a) Slab depth does not exceed 250mm when the steel grade is 250. bars should be arranged as distribution bars and are provided at 30 cm centres at the top of the. Conclusion. 2), The bar spacing shall not exceed 450 mm at any location (ACI Code Section 7. 3. , 300 mm. unless otherwise noted in plans or specifications, camber all r. W = 3. The distribution bars are arranged to retain the mesh in exact location and keep the center to center c/c, bars spacing among main bars. Main bar = 12mm@150mm c/c. Requirements regarding dowel bars and spacing of joints have been modified. 1 of IS 456), the maximum spacing is the lesser of 3d and 300 mm i. Actual variety of 1 sides rebar =Number of main bar – rebar of the middle. Distribution Bar. 1. member has shallow depth of less than 200 mm (ex. IS 456: 2000 CONTENTS PAGE SECTION 1 GENERAL J SCOPE 2 REFERBNCES 3 TERMINOLOGY 4 SVMBOU SECTION 2 MATERIALS, WORKMANSHIP, INSPECTION ANDTESTING 5 MATERIALS 5. Step Find the length of the dowel bar embedded in slab by equating Eq. 12% Gross area for HYSD bars, 0. Minimum area of slab reinforcement. 3m. C. The Main bars will be 12 mm in diameter with 100 mm c/c spacing. However, it is not a code, so many engineers do use portions of ACI 318 on their projects. 5db). In conclusion, the efficient design of two-way slab demands following a step-by-step approach according to IS 456. 7—Post-tensioning load redistribution Chapter 4—Strength adequacy of concrete slabs and formwork, p. 304. Spacing of bar = area of a bar * width of strip / area of reinforcement required = 78. 2. 7. e. The main bars will be 12 mm in diameter @100 mm c/c spacing. 5] = 120 mm c/c. No. • Maximum area of main steel in slab = 4% 𝑜𝑓 𝑏𝐷 (As per ACI). Number of Main Bars = Ly / spacing + 1 = (4000/150) + 1 = 27 nos. GameStop Moderna Pfizer Johnson & Johnson AstraZeneca Walgreens Best Buy Novavax SpaceX Tesla. 5 inches (Singh & Saini, 2019). C. Minimum Reinforcement Ratio in Slabs. 5. i,e. Difference Between Main Bars. Minimum reinforcement is ensured in slab (in both directions) to take care of shrinkage, thermal movements and. 3. The size of the stirrups should be chosen to avoid a closer spacing. Reading time: 2 minutes. 7. Number of bar =radius /spacing. 6. Step 1. 5. 6. 13. 1. The minimum and maximum spacing reinforcement in concrete structural members such as beams and slabs are required as per standard codes. of chair bars = Area of structural reinforcement in sqm / chair bar per sqm. 5 times effective depth d. 6 = 17. ”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. Slab steel bar not less than 10mm dia. spacing of reinforcing bars (cls. As bar is placed in longer span which is 4m. e. Earth Pressure intensity (q) = N/A prov = (18765. It is a useful reference for engineers, planners and contractors involved in bridge construction. Heavy loads. 4. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. 5. Design size and spacing of dowel bars at an expansion joint of concrete pavement of thickness 20 cm. Total Length of Distribution Bars = 786. 2. The previous code that allowed up to Grade 520 was changed to Grade 550, and related regulations were modified. Calculate Steel Quantity for Slab. 17 The design of one-way slab is simple and can be carried out easily. 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. 7. Question: Question 11 Not yet answered Marked out of 1. c. Most of these formulas are based on the analysis of results of tested beams or oneway slabs. t 12mm stirrups at 150mm ctrs Two terminated bars A A Elevation Section A-A Lsy. The slab requires 51 main bars. 1. Step 1: – Calculate numbers of distribution rods. 091 = 300. Design the slab using the data given below; Purpose of building – Residential. Size of the bar is less than the main bar. 12. dowel misalignment levels of less than 1 in. 2). 3 – When spacing of tendons exceeds 54 in. For columns exposed to weather or contact with the ground and embedded bars are No. The “D” bars shown in the tables conform to Article 9. Calculation for distribution bar: Bending moment for distribution. 9) Prepare bar bending. The manual design process included the reinforcement calculation for the main. 3. 5 bar or two No. are called concrete. Distribution Bar = 1800 -2 (75) ÷ 150 +1. 1. Spacing of bar supports depends upon the size of the reinforcing bar being. ment among different types of cements. 3. Concrete moisture conditions and drying rate. Distribution bars placed on top of the main bar. 1—Minimum flexural reinforcement in nonprestressed slabs 8. 304. 1905. Breadth of Footing = Y = 1. Now, we will calculate the length of the three parts of the chair bar separately. 5. The design method is followed as per Annexure D of IS 456:2000. 9. 2: Alternate method for showing two-way slab reinforcement reinforcing bars should be clearly scheduled on the drawings. 00mm Bottom Footing Clear Cover (F, CL). 6. For distribution bars (cl. with a banded tendon distribution is achieved without this. 347. 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. Dia of Chair. 9) Check for shear ( using Table 19 of code IS 456:2000). Table 1. Maximum size of bars in slabs As per clause 26. Modify ACI 318 Sections 17. 300mm. That is 11′. The no. 7. 24 SOLID SLABS 24. The minimum cover for cast-in-place concrete is specified by the ACI 318 Building Code. Spacing =150mm. 785 x d^2 = 0. This spacing should be reduced by a factor of 0. 4 Splices in reinforcement. Step 1. Learn More Estimate this Slab (Drawing Included) STEP 5. 140 M. The span requirement for the slabs is given by ACI Code 8. Spacing: ϕ8 mm: ϕ10 mm: ϕ12 mm: ϕ16 mm: ϕ20 mm: 100: 502 : 785: 1130: 2010: 3141: 125: 402:. The slab edge insulation for heated slabs shall not be required to extend below the slab. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. For a given area of tension steel areas, the distribution of steel reinforcement affects. 002 times the gross cross-sectional area of the footing. 5d = 5 * 130 = 650 mm. The below specified 7 steps are generally used to design the two way slab. The no. (b) One-way joist systems in accordance with 9. Main Bars and Distribution Bars in Slab and Their Function. 26. 78′ Say, 19′. 6. Assume diameter of bars and calculate spacing of bars. Step 1- Calculation of Numbers of Bars. 14. This type of reinforcement is convenient for modeling beam reinforcement. 3. Spacing of Main Reinforcement: The maximum spacing of bars shall not exceed. 5, the lateral spacing of the. Effective depth=d provided =120-20-4= 96 mm. 4. Provided to resist the bending stress. 60 kN/m. = 16 mm, spacing @ 150 c/c. 2. , 450 mm. Spacing of bars = 180 mm c/c < 300 mm and 3d ok Distribution steel =. 1. e. We would like to show you a description here but the site won’t allow us. FAQ . 1. 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. 167, hence it is singly reinforced. 12% of cross-sectional area as distribution rebars as per. 2 MineralAdmixtures 5. Main Steel Bars. 96 x 1000 / 1536 = 130. The maximum diameter of the reinforcement bars in R. 5 m as per IRC. 3(d) and 17. The maximum clear spacing between parallel bars shall not be more than 1 N-6O. 53 Compute moments At support: ( - ) M1 = 3. the quality and basic shape of reinforcement bar shall be specified. 8 ACI 318 , Section 17. 6. The size and number of reinforcing bars must be chosen to (1) provide an area of reinforcement equal to or greater than the amount that is required, and (2) satisfy the minimum and maximum spacing requirements in ACI 318-14, Building Code Requirements for Structural Concrete and Commentary. 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. On the bigger side, distribution bars are supplied, however, they will not assist in bearing any weight. 26. 7. 2. 6% of the gross wall area for Grade 60 or Grade 40 bars, respectively. 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. 1 Overview 4-1 4. Spacing of chairs should be per 1 m or 1 no. Distribution Bars are used to hold the slabs on either way and to resist the cracks. Reinforce concrete for a 5-inch thick concrete slab: For a 5-inch thick slab, #4 (1/2-inch diameter) rebar is commonly used. The Main. 21. Cutting length of main bar = Clear span of slab + (2 x development length) + Inclined length – (Bend length) Clear span of slab = 2000 mmFor one way slab, distribution bars are required to tighten the main bars together – since it has only one spanning reinforcement. What Is Bar Bending Schedule | Preparation as Per Bs 4466 | Tolerances as Per Bs 4466; Disadvantages of Dowel Bar. 8 ACI 318 , Section 17. (Main Bar & Distribution Bar Difference) Top and Bottom Clear Cover is 25 mm. Minimum number of bars for a square column are 4 and for circular column are 6. 11*12 in c/c Step 6 : Temperature and Shrinkage ReinforcementWeight of distribution of 8 mm dia steel bar = 33. 1. The distribution bars should be (2000- 2 x 25) /125 + 1. Chapter 9 which is also per mitted per ACI 349-06 Appendix D. C. Calculation of the loads. b) Slab depth does not exceed 200 mm when the steel grade is 460. The bigger span in the above slab, 5000, divided by the shorter span, 2000, is 2. No of main. 0018. In case of HYSD bars, minimum reinforcement along either direction shall not be. 1. slab known as a joist system can be constructed without any shear reinforcement in the joist ribs. No of Bars/m 2 = Factored Load / Pcr. Having <0. 5m . That is: 19′. 2 shall be provided between the ten-dons at slab edges extending from the slab edge for a dis-tance equal to the tendon spacing. 9. 12. ratio of flexural stiffuess. How to calculate reinforcement bar spacing How to calculate Minimum Bar Spacing for Bundle Bars in Cast-in Place Concrete as per AASHTO provisions. 5. Sketch the detail of reinforcement. 1. 225m. A = roof area in square feet drained by the drainage system. 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. 3. 2. 3. 2 For one-way shallow foundations, two-way isolated footings, or two-way combined. Unit weight of concrete = 25 kN/m 3. C. 4 Water 5. 33=16 no’s. The distribution bars are arranged to retain the mesh in perfect place and sustain the center to center c/c, bars. Use bar support in order to maintain the space between bars at the top and bottom and then the distance will be correct. Fig. 12. Number of Main Bar & Distribution Bar: First, we have to calculate the number of bar required for the slabs. Ex. e. Temperature distribution due to heat of hydration and internal stresses caused by outside cooling in a free standing concrete block. 4 Minimum Eccentricity Step 5: Calculation of Steel Weight. 3 – When spacing of tendons exceeds 54 in. 6. 3. 7. Concrete Reinforcement January 2008 15-3. design wheel load. For slabs less than 200 mm thick the following maximum spacing rules apply: For the principal reinforcement: 3h but not more than 400 mm. Now assume diameter of bars and calculate spacing between bars. 31kg says 35kg. Also useful for attaching stirrup bar effectively. 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. In case of HYSD bars, minimum reinforcement along either direction shall not be. assume corners are held down. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. 3 ANALYSIS 3. 7. 12. 7. spacing of bars should not be more than. 1% steel allows sawed contraction. 1000 1500 2000. 97 kN/m 2. cm for 1 m width of slab where D is the overall depth of slab. 3. Diameter of a chair bar should not be less than 12mm. 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. 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. 2. 6. Cryptocritical section of the slab is just outside the outside edge of the beam supporting the slab. The wires or bars will be lapped as follows. b. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. Distribution bars:-These bars are straight bars. 2. Now. As per clause 26. 1. 3% (100As/bd < 0. For distribution bars, the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is smaller. 6 = 17 bars; The number of distribution. Exceeding a joint spacing of 15 ft. 5 m as per IRC. Table 1. 3. The depth of voided slabs could reduce the height of the structural system up to one foot per floor compared. 3 Required Strength 4-2. 4. If it is desired to replace 10 mm bars by 12 mm bars, then the spacing of 12 mm bars should be. Top & bottom distribution bar dia. From a study that compared voided slabs and solid slabs, researchers observed that for typical bays of 7. Figure: Contraction joint;. 6. Thickness of Slab = 0. 1-1 and its accompanying notes, except as modified herein. Main Steel – 3d or 300 mm whichever is smaller. 1-3). with 12mm. TWO WAY SLAB DESIGN SPREADSHEET:Fig 10: Reinforcement of a slab. 6 in the following cases; In sections within a distance equal to 4 × thickness of wall above or below a beam or slab. 40 mm or diameter of bar whichever is more 2. For instance, the ACI 318-19 specifies minimum slab thickness that satisfies deflection. If a closer spacing of bars is required at the columns, as per Section 13. 5. The clear cover will be 25 mm(Top or Bottom) and the thickness of the slab is 150 mm. 8. 8. Since diameter of bar = 10 mm. Given data: Distribution bar dia. Only 2. 5. Clear cover (top & bottom) = 50 mm. Provide 0. c. slab, shall not. In design of slab, as per IS-456, what should be minimum percent of distribution steel if Fe 415 reinforcement is used ? The minimum percentage of reinforcement is 0. 0146. 1 of code IS 456:2000. 2.