Unit weight for feet per metre = (D2/ 533) × L kg/ft. As per IS 456:2000, in rcc slab, maximum diameter of main bar and distribution bar should not exceed 1/8th thickness of slab. 10 cm; 12 cm; 14. 1. 890m. 300 Area of bars Φ12, a=π62 = 113. 0020. Sub-slab details (i. purchase orders, drawings, or per diems shall be done at the risk of those making such references or quotation. 1. What Is The Maximum Bar Spacing In Reinforced Beams According To IS 456? Normally this. Collectors, Chords and ConnectionsIS Code. 10mm Ø hor. 3. Number of bar =radius of slab/spacing. 2. Compute number of steel bars. 1. Refer to Section 5. tangential spacing of legs of links, st max. 150m = 150 mm. Distribution bars of diameter 12 mm and center to center spacing 150 mmm. 12% of the total cross sectional area , when HYSD bars Fe415 are used. = 16mm, spacing @ 150 c/c. 4. Lap length 50d = 50 × 16mm = 800mm. Slab steel bar spacing maximum 150mm c/c. 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. 960m. 2. Distribution Bar = width of the foundation – 2 CC ÷ Spacing +1. 11in2) Spacing = As 0. Tech. Main Steel – 3d or 300 mm whichever is smaller; Distribution Reinforcement for. anchorage to longitudinal bars and confinement of core concrete in resisting shear2. . 6 For two‐way slabs, maximum spacing of bars shall not exceed two times the slab thickness h nor 450 mm. Ensure that the return bars at the edge of the slab are a minimum of ¼ (15%) of the length of the adjoining span. Distribution bars are 8 mm in diameter @ 150 mm centre to centre spacing. As discussed earlier, assume that the beam is reinforced with two layers of #11 reinforcement and clear spacing between layers = 1 in. Note: The minimum clear spacing of bars is not kept less than 75 mm (Preferably 100 mm) though code do not recommend any value. 6. Number of bar = 1. To calculate: Spacing of replaced 12mm. These bars should be distributed as evenly as possible between the negative moment design sections, with one bar being placed at the inside of each bottom truss bar bend. “D” bars (Distribution bars) - Longitudinal bars in the bottom mat of deck reinforcement. 4 Deck Overhangs for guidance on deck slab bars. = 16 mm, spacing @ 150 c/c. 6. Depth of footing = 750 mm. The distribution bars are arranged to retain the mesh in perfect place and sustain the center to center c/c, bars. The no. 5. 12. of Main bars = (3000)/150 + 1. Main Bar. Design Guide on the ACI 318 Building Code Requirements for Structural Concrete. Number of Main Bars = (Length of Longer Side / Spacing) + 1 = (6000/150)+1. Step 1. 3d or 300 mm whichever is smaller for main steel. 1. For 8 mm diameter bar 7 inches to 9 inches center to center c/c. 7. 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). Minimum S&T reinforcement quantities required by ACI 350-01 and11. Calculate Steel Quantity for Slab. 53 Compute moments At support: ( - ) M1 = 3. R4405. Spacing of Main reinforcement bars = s m = 150mm c/c. 3 of IS 456) 20 KTUNOTES. Note: The minimum clear spacing of bars is not kept less than 75 mm (Preferably 100 mm) though code do not recommend any value. Maximum spacing of bars for slabs • Main bars: 3h ≤ 400mm (in areas of concentrated loads 2h ≤ 250mm) • Secondary bars: 3. correct. 2, with “S” assumed to be equal to the length between negative moment design sections. Thus, there are three relevant issues: 1) According to ACI 318-19 Section 7. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. 6. Type and spacing of the control and construction joints. 5. 5 inches, and the transverse bars must be fully developed in grouted masonry at the point where they cross the lapped reinforcement. each way at center of slab construction joint for same shall not be more than 3000mm apart. C. ACI 318-19, Table 8. 1 of code IS 456:2000. Slab steel grid not less than Fe500. 2. 4. Number of Distribution Bars = Lx / spacing + 1 = 3000/150 + 1 = 21 nos. 6 in the following cases; In sections within a distance equal to 4 × thickness of wall above or below a beam or slab. 13. For Min Steel: 3d ——— Where. 5—Application of the simplified method 3. 1 - 10mm Ø vert. Concrete Slab Design ProcedureSteel reinforcements can be use, however with a maximum spacing of 4. 2 times effective depth b. 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 times effective depth c. Note: The minimum clear spacing of bars is not kept less than 75 mm (Preferably 100 mm) though code do not recommend any value. Dia of Distribution Bar=16mm. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. ,). 7 Storageof MaterialsThere are 2 types of bars in two-way slab: Main Bar & Distribution Bar; Main Bar Diameter = 10 mm; Spacing Between Main Bars(C/C distance) = 150 mm; Distribution Bar Diameter = 8 mm; Spacing Between Distribution Bars(C/C distance) = 100 mm; Length of Slab = 6000 mm; Width of Slab = 3000 mm;. Number of Required Bars Formula = (Length of slab / spacing) + 1. Requirements regarding dowel bars and spacing of joints have been modified. 3-Main bar Bottom Area Given data. Larger areas, lower loads, and higher seismic zones. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. 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 For two‐way slabs, maximum spacing of bars shall not exceed two times the slab thickness h nor 450 mm. 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. 1. 2. Distribution bars:-These bars are straight bars. 7. 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. Lits-II 1. 6H, and 0. 1. member has shallow depth of less than 200 mm (ex. 6. 5. = 2sqm/1sqm = 2nos. 2. Given Data: Height of footing = 600 mm. Exceeding a joint spacing of 15 ft. But even after that If d,provided < d,reqd, slab thickness is to be increased and check for deflection is to be satisfied. 7. , addi-tional bonded shrinkage and temperature reinforcement conforming to 7. 5. 2. The distribution bars number 17 in total. 2. 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. thick slab will increase the potential for random or out-of. 23 Total factored load = 6. 7. Total length = 3. (b) Horizontal reinforcement at least 0. For eg. 5. Spacing between bars = 0. 1. 2. C. 2. For Edge Spans : Static Mom. 8. The continuous vertical bar required beside an opening is permitted to substitute for one of the two No. 7. 5. The cross‐sectional area of one N28 bar is As = 620 mm2 and with N12 stirrups at 150 mm centres, Atr = 110 mm2. , Structural. 4 must be met, and max. 0m from the fixed end. Design procedure. So we have total 16 nos of distribution Reinforcement bar so the total length is. As bar is placed in longer span which is 4m. Top & bottom distribution bar dia. The minimum spacing between the two bars can be about 50–75 mm. The “D” bars shown in the tables conform to Article 9. 1123 mm. 5 Spacing limits and concrete cover for reinforcement shall be shown on the design drawings. design wheel load 4000 kg. d = Effective depth. As always, local service records are the best guide for determining trans verse joint. 3. 5 M from the edge of wall and at both ends 6 mm plain M. 2Dead Load + 1. 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. Concentrated reinforcement is a fixed number of bars over a parallelogram area. 6. The design of one-way slab is simple and can be carried out easily. 2—Construction load factorsThe diameter of the main bar should not be less than 8mm for the HYSD bar and 10mm for plain bars. 3. Use #4 bars at 25-inch spacings center to center each way, As = 0. 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. 1. B. Step 1: – Calculate numbers of distribution rods. Area of One Bar 20114 Sqmm 16 RESULT Spacing of Distribution Bars 360 mm 16 from BSCE 11234 at Xavier University - Ateneo de CagayanThe maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. If it is desired to replace 10 mm bars by 12 mm bars, then the spacing of 12 mm bars should be. For basic building the 4 number of bars is sufficient as per code. 090 square inches per foot of slab width, required each way. Maximum size of bars in slabs As per clause 26. c. and floor finishes 1 KN per meter square. Bar Bending Schedule Of Slab (Two Way) Ly/Lx = Longer span/Shorter span = 5000/3000 = 1. 2 or 8. 2. 3 ANALYSIS 3. 975 KN)/ (39. 27. 26. is the strength reduction factor as specified by table 21. Cover block use 15 to 20mm. 15%of gross cross-sectional area if plain bars are used and 0. 8. 11. 6. There are 51 nos of main bars are required for the slab. Spacing of bar = area of a bar * width of strip / area of reinforcement required = 78. Weight of the bar as per their length and. Step 1. TWO WAY SLAB DESIGN SPREADSHEET:Fig 10: Reinforcement of a slab. Effective depth=d provided =120-20-4= 96 mm. The maximum spacing of bars shall not exceed. The slab edge insulation for heated slabs shall not be required to extend below the slab. Tech. Figure 3:. Given the radius of relative stiffness of 90 cm. The code itself suggests that the diameters can be #3, #4 and #5. For a 6 in. Most of these formulas are based on the analysis of results of tested beams or oneway slabs. 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. Spacing of bars = 180 mm c/c < 300 mm and 3d ok Distribution steel =. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. 5. 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. Sub-Grade and. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. For concrete cast against and permanently. 14 x r x r) = 3. Reinforce concrete for a 5-inch thick concrete slab: For a 5-inch thick slab, #4 (1/2-inch diameter) rebar is commonly used. 26. bars in two-way slabs. Check spacing of bars. In case of mild steel, minimum reinforcement along either direction shall not be less than 0. 3. The maximum spacing of reinforcement at critical design sections for positive and negative moments in both the middle and column strips shall not exceed two times the slab thickness (ACI Code Section 13. b) Slab depth does not. 5% steel (continually reinforced) as described in Section 8. 3. According to ACI Code. Distribution Bar = 10 mm, Spacing – 150 mm c/c, Alternate bent up. 5, the lateral spacing of the. 7. 17 The design of one-way slab is simple and can be carried out easily. Modify ACI 318 Sections 17. However,. 9. 230/0. As per IS 456: 2000, clause 26. ”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. 2. bars are used as distribution bars and are placed at 30 cm centres at the top of the bottom bars. Design the slab using the data given below; Purpose of building – Residential. 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. slab should not exceed three times the effective depth of the slab or 450 mm whichever is smaller. As per ACI Code, In slab, minimum reinforcement shall be 0. 2 Maximum Distance between Bars in Tension. 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. Bar Spacing. Workmanship and jobsite conditions. advantage of the smaller lap lengths required for top slab bars. For main bars, maximum spacing is restricted to 3 times effective depth or 300 mm whichever is smaller. Minimum distribution reinforcement steel (for TOR Steel) shall be 0. Maximum size of bars in slabs As per clause 26. 4 bar at the top and the bottom. To firmly hold the main bars in their. of chair bars = Area of structural reinforcement in sqm / chair bar per sqm. 2. Here we have to calculate the number of main bar and distribution bar. 3 m) is either 0. b) Slab depth does not exceed 200 mm when the steel grade is 460. Height of block wall = 2. 9, page 341. slab known as a joist system can be constructed without any shear reinforcement in the joist ribs. Spacing of chairs should be per 1 m or 1 no. The no. 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. 4 Minimum Eccentricity Step 5: Calculation of Steel Weight. The manual design process included the reinforcement calculation for the main. spacing in plates and two-way slabs with concrete covers. Sub-slab details (i. 5 inches (Singh & Saini, 2019). 1. Minimum Bar Size : 16 mm Maximum Bar Size : 25 mm Top Footing Minimum Bar Size : 16 mm Top Footing Maximum Bar Size : 25 mm Pedestal Minimum Bar Size : 16 mm Pedestal Maximum Bar Size : 25 mm Minimum Bar Spacing : 100. 5. c. Section 8. 7. 1 given below. Development Length (Ld) = 40d. 2 Spacing s of transverse bars in precast walls shall not exceed the. Q) Calculate the quantity and weight of steel rod in a one-way slab having length 6 m, width 2. 97 kN/m 2. Cutting length= 9000 – 2 x 50 =8900 mm =8. 9. In this article I will explain you complete slab design as per IS 456 code by using manual method. No. 3 – When spacing of tendons exceeds 54 in. Important Points. The following minimum limitations relating to various structural components shall be followed: Thickness of top flange : 100 mm. The distribution bars provide the following functions in slab construction: 1. shall be the lesser of (i) five times the effective depth, or (ii) 450 mm. 5 m). a) Slab depth does not exceed 250mm when the steel grade is 250. Width of the Slab = 2 m = 2000 mm. 5. Design of slab. Distribution Bar. 42D) – (1d x 4) – (2d x 2 (From BBS shape codes) d = diameter of the bar. spacing of bars should not be more than. . Main bar = 12mm@150mm c/c. 26. joint spacing greater than 50 ft (15. 0146. slabs, walls, and joists - #14 and #18 bars - ½ inch; Slabs, walls, and joists - #11 bars and smaller - ¾ inch ; Beams and columns. 14 x r x r) = 3. In RC slabs and PT one-way slabs, the clear distance between bars is limited to the smaller of. Tech. 5. 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. (b) One-way joist systems in accordance with 9. DESIGN OF SLAB: Design of typical Floor Slab: We have thickness of slab as 130 mm. Step 1 – Find out the Total Number of Main Bars & Distribution Bars. 12% of the total cross sectional area , when HYSD bars Fe415 are used. 3. Design a one-way slab having a simple span of 3 m. 6% of the gross wall area for Grade 60 or Grade 40 bars, respectively. The slab is. 5. 34 kg ——– (1) Section 1 Total = 33. 167, hence it is singly reinforced. dia. 31 of IS456-2000, the span by depth ratio of two way slab is applicable for flat slabs and the values can be (l/d)modified by 0. 2. 14 m, and 10. The maximum reinforcement ratio for columns is 0. R403. Max. 1 of IS 456:2000, the reinforcement in either direction ,in slabs shall not be less than 0. 75 Nos. 2R-8 4. 11 bars and smaller, continuing reinforcement provides double the area required for flexure at. 0. Check for Cracking. 3. 21. Conclusion. slabs is Thickness of slab/8 14. 6. Bar Spacing. Load Calculation: Live Load = 2 kN/m 2. 11. BS EN 1992-1-1 Annex 1 1. f ck = 25 Mpa. 5. 7. C. In Flat plate slab the, distribution bars are arranged in one direction at Top of main bar (in longer span). slab along the shorter span, 3mm per meter span. Step 3 – Top Distribution. Distribution bars are provided perpendicularly with the top of the main bar. Waist slab Bar Bending Schedule. 26. That is 11′. 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. Minimum number of bars. 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. Step 1 – Find out the Total Number of Main Bars & Distribution Bars. No. One Way Slab Bar Bending Schedule Calculation. 4. 12. The steel reinforcement in SS/NS wall and slab shall be welded steel fabric mesh for steel bar diameter of up to 16mm and hot rolled steel bars. Main Steel – 3d or 300 mm whichever is smaller. 3—Corner restraint in slabsColumn = Self Weight x Number of floors. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. IF Grade 50 to 60 deformed bars or welted wire reinforcement are used9. 18D sq. 1. Weight of Main Bar = (102/163) x 126. 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. 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. bar due to its non-availability. 1905. 6. 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. Ensure a minimum number of bars in a square column is 4 and in a circular column, 6. Check resistance to moment transfer from column to slab . C. 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. So, provide spacing of. e. 9. 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. dia. 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. 7. Cranking is also used in two way slabs. 3. However, it is not a code, so many engineers do use portions of ACI 318 on their projects.