Each alternate bar is cranked up to 0. 7. 10mm Main Bars @ 150mm C/C spacing; 10mm Distribution Bars @ 200mm C/C Spacing; Development Length L d = 40d; Top Extra Bar 8mm @ 150 mm c/c (both direction) Bar Bending Schedule for Two Way Slab. Spacing: ACI Code 7. Size of the bar is higher than the distribution bar. 2, The diameter of reinforcing bars shall not exceed one-eighth of the total thickness of the slab. The wires or bars will be lapped as follows. Design ProcedureAllowable clear spacing of bars = 3d = 3(170) = 510 mm Actual clear spacing = 300 – 10 = 290 mm < 3d → ok Figure 3. 2. The complete calculation for one way slab is explained in the below steps. Main Steel – 3d or 300 mm whichever is smaller. Before calculating the cutting length, we need to calculate each part length of chair bar. d = Effective depth. As per IS 456: 2000, Cl. Design of the footing cantilever slab portion (per meter strip) Note that the bending moment in the slab is maximum. 13. Unit weight for feet per metre = (D2/ 533) × L kg/ft. 3-Main bar Bottom Area Given data. the square of the thicker slab when f=0. 6% of the gross wall area for Grade 60 or Grade 40 bars, respectively. 6. Mild reinforcing bars shall have minimum clear spacing of at least 2 in. Table 1. Development Length (Ld) = 40d. 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. 2. 1 Cement 5. For distribution bars the maximum spacing is specified as 5 times the effective depth or 450 mm. 9) Check for shear ( using Table 19 of code IS 456:2000). length of. of distribution bars = Ly/Spacing + 1 = 2000/150 +1 = 14. Main Bars and Distribution Bars in Slab and Their Function. 3 Direct supply of steel reinforcing bars to site by QA Manufacturer 27 Section 5 Purchasers testing 28 5. The maximum spacing of minimum steel (distribution bars) is the lesser of 5(135) and 450 mm. 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. It is a two way slab. 4—Construction load distribution 3. The primary reinforcing bar is placed perpendicular to the bigger side or parallel to the shorter direction to give suitable support. (table 15). 5db). 2. Clear Cover = 20 mm. 3. 2, can form no closer to the facesee table 3 for spacing. 1. member has shallow depth of less than 150 mm (ex. Step Assume load capacity of dowel bar is 40 percent wheel load, find the load capacity factor f as. For Edge Spans : Static Mom. purchase orders, drawings, or per diems shall be done at the risk of those making such references or quotation. Given the radius of relative stiffness of 90 cm. cm. Calculation of the loads. Only 1 D. 2—Construction load factorsThe diameter of the main bar should not be less than 8mm for the HYSD bar and 10mm for plain 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. Is 1200 Important Point Part-1; IS Code for Civil Engineer [Q&a]. 5, the lateral spacing of the. EXAMPLE PROBLEM 1. Given, Cranked bars or Main bar of diameter 16 mm and center to center spacing 150 mm. Question: Question 11 Not yet answered Marked out of 1. 15% gross c/s of slab – for MS bars; 0. 7. Business, Economics, and Finance. Slab steel bar spacing maximum 150mm c/c. slab, shall not. 12. b) Slab depth does not. 6—Factors affecting the construction load distribution 3. How to Design Concrete Structures to Eurocode 2 - Chapter 7 : Flat slabs and Figure 6. 090 square inches per foot of slab width, required each way. This is plotted against the overall fire rating of the structure that is being designed. 2 Effective Length ofCompression Members 25. 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. 5, the lateral spacing of the. 5 bars required by 14. 6. bars at every 3 layers of chb finished surface corner wall detail 1 - 10mm Ø vert. 2. 5. stationary live loads less than 400 po unds per square foot. 300mm. continuous slab – code coefficients-. The maximum spacing of main bars is limited to 3d or 300 mm (whichever is less). The clear cover will be 25 mm(Top or Bottom) and the thickness of the slab is 150 mm. 3 only and there is no need to perform specific checks on the bar spacings to control cracking. = 27. Table 1. 85MPa) was added as a code requirement. 2. The larger the diameter of the bar, the more the spacing is, and vice versa. , 0. 7. Since diameter of bar = 10 mm. 9. Height of the footing (Thickness) = h =0. 12. to carry a uniform live load of 7500 Pa. 13. 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. Reinforcement chairs should be made with a minimum of 12 mm bar. In this article I will explain you complete slab design as per IS 456 code by using manual method. 12% of the total cross sectional area , when HYSD bars Fe415 are used. 12 % of the gross area if the HYSD bar (Fe415) is used. Total length = 3. As per IS 456: 2000, Cl. 5, which equals 51. The reinforcing bars must extend into the slab beyond the critical section for a required length. 5. 3. 6. M. 6. 5% steel (continually reinforced) as described in Section 8. Maximum size of bars in slabs As per clause 26. Tech degree in Civil Engineering with six specializations, i. a = axial spacing of the bar for calculating the lap length (ci. A = roof area in square feet drained by the drainage system. =Eq. 1. 1 General 24. 12. 5 m as per IRC. Sub-Grade and. per 1 m 2. Cutting Length: = total length — 2 x clear cover = 4000 - 2 x 20 = 3960 mm or 3. “D” bars (Distribution bars) - Longitudinal bars in the bottom mat of deck reinforcement. This is also. 5. 2and3 C. This value is commonly used in design today as the minimum. 4 Spacing Between Longitudinal Bars. of chair bars = Area of structural reinforcement in sqm / chair bar per sqm. 2 As per NSCP 2015, a minimum shear reinforcement in concrete design shall be provided in all regions where Vu > 0. 5. 3. Main Bar = 12 mm, Spacing – 150 mm c/c, Alternate bent up. The design of one-way slab is simple and can be carried out easily. Bar Spacing. 7. 12. 1. member :. No of main. Top & bottom distribution bar dia. 1. For footings that exceed 8 inches (203 mm). s code Sandeep Yadav. Weight of Distribution Bar for Waist Slab. Distribution Reinforcement for Stairs. 26. Distribution Bar. 5 b w d): For longitudinal bars bent at 45 degrees, the second equation above is replaced by S max =3d/4The spacing of distribution bars having diameter 10 mm should be 9 inches to 12 inches center to center c/c. 12. k < 0. Effective depth=d provided =120-20-4= 96 mm. 5. The maximum anchor nominal diameter is 5 / 8 inch (16 mm). iv) Detrmine Sapcing of bars at critical section based on designed value of Ast by selecting appropriate bar dia. In both cases, the minimum bar areas are equal to 0. 8. 2, or >0. This spacing should be reduced by a factor of 0. As per ACI Code, In slab, minimum reinforcement shall be 0. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. Figure 3. Diameter of top and bottom distribution bars = 16 mm. 31kg says 35kg. The following minimum limitations relating to various structural components shall be followed: Thickness of top flange : 100 mm. Provided to resist the shear stress and cracks. 5. Provided to resist the bending stress. 2. 4. Important Point: As per IS 456:2000, the limit on minimum reinforcement along either direction has been specified. Now, we will calculate the length of the three parts of the chair bar separately. e. Number of bar = 2150/150+1= 15. 3. Waist slab Bar Bending Schedule. 7. Radius =length /2. The previous code that allowed up to Grade 520 was changed to Grade 550, and related regulations were modified. 2 and 9. 5. 4. ”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. 83 mm. 1 or the bottom bars required by 8. Calculation of number of distribution bars. The ideal spacing for these bars is around 18 to 24 inches on center (from the center of one bar to the center of the next), depending on the expected loads and local building codes. c 0. (a) for a distance equal to the larger lateral dimension of the column above and below a beam or slab, andvii) Any other function assigned to the expansion joint as per the specific requirements of the structural systems. three times the effective depth of solid slab or; 300 mm; whichever is smaller. The length of a distribution bar in west side is the same as the east side. 1 for minimum thickness of non-prestressed two-way slabs without interior beams is revised to include Grade 550. C. 1. Here, ∅ is the bar diameter. What is the maximum spacing of bars in slab? 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. How to Design Concrete Structures to Eurocode 2 - Chapter 2: Getting started. Assume diameter of bars and calculate spacing of bars. design wheel load. 26. e. 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. the total length of the leg is 2×spacing +50. 1. 5. Distribution of Main Bars. 11in2) Spacing = As 0. 64 2 )/8 = 23. maximum spacing of reinforcement in slab as per is code the maximum spacing between two parallel main reinforcing bars in case of RCC Slab shall be 3d or 300 mm or whichever is less. 6. 2 Minimum Slab Thickness 4-1 4. 3. 3 Required Strength 4-2. b) Slab depth does not exceed 200 mm when the steel grade is 460. 2 or 8. Cranking is also used in two way slabs. 8. 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. 2 or 8. One Way Slab Bar Bending Schedule Calculation. S. Weight of rod per meter length = d 2 /162 where. #IS456Explanation#SpacingofReinforcement#IESGATEWizIn this Video Part-45,detailed discussion of IS 456-2000 provisions of Spacing of Reinforcement Bars ha. Whereas, Factored Load = 1. If a closer spacing of bars is required at the columns, as per Section 13. 5 in Y-axis Distribution area 3. All values are taken except ‘D’ in the above formula. e. Now. 3. 6. Distribution bars are provided in the longer span direction. Eurocode 2 section 9. Larger areas, lower loads, and higher seismic zones. 78′ Say, 19′ >WEST side. How to calculate reinforcement bar spacing How to calculate Minimum Bar Spacing for Bundle Bars in Cast-in Place Concrete as per AASHTO provisions. VARIATION AMONG BETWEEN MAIN BARS AND DISTRIBUTION BARS: 1. 4 Deck Overhangs for guidance on deck slab bars. 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. Plain 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. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. c) Slab reinforcement percentage less than 0. A s,min,reqd ≥ b*h*0. 27. Distribution of Main Bars. Distribution Bar. 3. 3. In case of mild steel, minimum reinforcement along either direction shall not be less than 0. 5—Application of the simplified method 3. 10m , Depth of Slab = 0. 18/100× × 100× D = 0. Dia of Chair. 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. The Main bars will be 12 mm in diameter with 100 mm c/c spacing. 75 m. c. 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. EXAMPLE PROBLEM 1. Factor affecting spacing of chair bars. In general we use 5 inch (125mm) thick slab, if thickness of slab is 125mm,then maximum diameter of bar used in slab is 125/8 which is equal to 16mm. 090 square inches per foot of slab width, required each way. 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. Thickness of Slab = 0. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. The distribution bars should not be under 8 mm in a diameter or not be over 1/8 of the thickness of the R. reinforcing parallel to load per inch of slab width perpendicular to load / slab thickness) (steel yield stress)) f. Bars shall not be smaller than No. , if the upper bar of 16mm dia. 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. 12: Reinforcement detail in continuous slab 3. 2 (7) Beams: the maximum longitudinal spacing of bent-up bars s b,max; 9. 6. 3(d) and 17. The maximum spacing of bars shall not exceed. 896 x Total Length (where d is in # Nos. 5-2 Recommended spacing of transverse. Cranking is also used in two way slabs. BS EN 1992–1–1 section 6. 5. 60 kN/m. So may be in this case, chair may be required more. Step 1 – Find out the Total Number of Main Bars & Distribution Bars. Now, we need to replace the distribution bar of 10mm. 12. 2) height of chair:- vertical distance of chair bar is known as height of chair, it is main part of calculation to find and how to calculate height of chair bar Height of chair = depth of footing _ (upper and lower clear cover of concrete + bottom. The code itself suggests that the diameters can be #3, #4 and #5. 12% Gross area for HYSD bars, 0. 2. . Near lapped joints, if the diameter of the longitudinal bar is greater than 14 mm. D. 5. 5 inches (Singh & Saini, 2019). 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. Tech. 7. Clear span of the two way slab = 5000 mm. The distribution bars should be (2000- 2 x 25) /125 + 1. 2: Alternate method for showing two-way slab reinforcement reinforcing bars should be clearly scheduled on the drawings. The slab is supported all around walls of width 300 mm. Roof drainage system (Adapted from the International Code Council). 1 or the bottom bars required by 8. 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. 15% for Mild steel bars. e. Distribution bars are provided perpendicularly with the top of the main bar. the constant value of 50. FIrst, find number of rods required for main reinforcement and distribution. The transverse bar must be No. 14. The equivalent of closer-spaced, typical slab bars can be achieved f DESIGN of ONE-WAY SLAB based on NSCP 2015 and ACI 318-14. For 8 mm diameter bar 7 inches to 9 inches center to center c/c. slabs) or. 26. To calculate: Spacing of replaced 12mm. BS EN 1992-1-1 Annex 1 1. Spacing of main reinforcement bars = 1000/ [A st,req / Area of single bar] = 1000/[660 / 78. The length of a distribution bar on the south side will be the same as the north side. 3. 1 or the bottom bars required by 8. 3 m) is either 0. If the reinforcing bars do not extend beyond the critical section. Design of slab. 2) The horizontal distance between parallel reinforcement bars provided against shrinkage and temperature shall not be more thanACI 360R-102 is a major resource covering design of slabs-on-ground. 6. to carry a uniform live load of 7500 Pa. Fig. Difference Between Main Bars. In Flat plate slab the, distribution bars are arranged in one direction at Top of main bar (in longer span). of Main bars = (3000)/150 + 1. 6. design wheel load 4000 kg. than that calculated as per Sections 12 and/or 16 (whichever is higher) of IRC:112. No. e. The slab is. The cross‐sectional area of one N28 bar is As = 620 mm2 and with N12 stirrups at 150 mm centres, Atr = 110 mm2. That is 11′. The span requirement for the slabs is given by ACI Code 8. The code requires this value to be the minimum of these three values. how to calculate the number of rebar in an exceedingly circular block. Compute number of steel bars. 3. The slab is. R403. For longitudinal reinforcement in columns of size 200 mm and less, with 12 mm diameter bars as longitudinal steel. In conclusion, the efficient design of two-way slab demands following a step-by-step approach according to IS 456. 2, with “S” assumed to be equal to the length between negative moment design sections. Here we have to calculate the number of main bar and distribution bar.