6 𝑀𝑃𝑎. The complete calculation for one way slab is explained in the below steps. Length of distribution bars = 6. 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. Bar schedule for Slab; Table 3 : Bar schedule for SlabArea of single bar = (3. 6. 096 square inches per foot (or #4 bars at 18 inches center to center to meet ACI criteria, As = 0. 1 (3) Solid slabs: the maximum spacing of flexural reinforcement bars s max,slabsThere are 2 types of bars in one 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;. 9 Factored loads Factored dead load = 3. Now, we will calculate the length of the three parts of the chair bar separately. DESIGN OF SLAB: Design of typical Floor Slab: We have thickness of slab as 130 mm. 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. 12. 3. 3. 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 ). 6. The reinforcing bars must extend into the slab beyond the critical section for a required length. 3. e. = 27. bars are used as distribution bars and are placed at 30 cm centres at the top of the bottom bars. C. 3. Provided at the top of the slab. Concrete moisture conditions and drying rate. The cross‐sectional area of one N28 bar is As = 620 mm2 and with N12 stirrups at 150 mm centres, Atr = 110 mm2. 3. exposed to earth or weather. unless otherwise noted in plans or specifications, camber all r. 15%of gross cross-sectional area if plain bars are used and 0. The maximum spacing of main bars is limited to 3d or 300 mm (whichever is less). 9, page 341. 1. Main Steel – 3d or 300 mm whichever is smaller. 8 ACI 318 , Section 17. Basically slab is the horizontal member which is rests on the beam section. 26. It is appropriate to design the slab per unit width, hence b = 1000mm. The slab requires 51 main bars. Spacing of Main reinforcement bars = s m = 150mm c/c. (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. 3. 5] = 120 mm c/c. 2. 896 x Total Length (where d is in # Nos. Top & bottom clear cover = 50 mm. 1. Spacing of chairs should be per 1 m or 1 no. 4. Maximum spacing: The maximum spacing of main bars is limited to 3d or 300 mm (whichever. 4. 0018 times the slab's gross area, but the maximum spacing of the bars differs. 2. 6—Factors affecting the construction load distribution 3. Spacing s of longitudinal bars in precast walls shall not exceed the lesser of (a) and (b): (a) 5h. 12: Reinforcement detail in continuous slab 3. In Flat plate slab the, distribution bars are arranged in one direction at Top of main bar (in longer span). 2 of IS 456) shall not exceed 140/8 = 17 mm is also satisfied with the bar diameters selected here. 2 BS 8110-1:1997) Width of the beam = 500mm = 0. • Maximum spacing of shrinkage or temperature bars shall not exceed the lesser of 5ℎ and 450 𝑚𝑚 • Specified concrete cover of primary reinforcement for cast-in-place slabs not exposed to weather or in contact with ground 36 mm∅ bar and smaller is 20 𝑚𝑚; and 16 𝑚𝑚 for precast slabs (see NSCP Table 420. 2. 7. Development length =40d . No of bars = 41 nos. For preparing the bar bending schedule according to the given data. 4H to 0. 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. 2 – Spacing of tendons shall not exceed 6 feet. Placed at a shorter span. For distribution bars (cl. So, Provided area of steel reinforcement, Ast=2416 mm 2. 6. 96 sq mm. A beam is similar to a slab in so many ways but there are fundamental differences in behaviour and stress distribution of the two. (b) One-way joist systems in accordance with 9. Here, ∅ is the bar diameter. 12% of the gross cross-sectional area if HYSD bars (Fe 415) are used. 3. Q) Calculate the quantity and weight of steel rod in a one-way slab having length 6 m, width 2. 3) For distribution bars, the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is smaller. critical section of the slab is just outside the outside edge of the beam supporting the slab. 9) Prepare bar bending. however with a maximum spacing of 4. 3. 6. àIn case the thickness of slab is 120mm, the height of bent bar should be 60mm. Full bond Full bond h/2 Filler Figure 15:3: Contraction joint 15. 1. 2. However, it is not a code, so many engineers do use portions of ACI 318 on their projects. 3 introduces a new requirement for barBridge Deck Slab Design Example as per IRC Indian Codes, Deck Slab Bridge Design are described step by step by Using Limit State Method. 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. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. Spacing between bars = 0. Exceptions: 1. The length of a distribution bar in east side is, = (17′-1½″) + 2 × 10″ = 18. 7. (b) For No. Bar Spacing. Hence, in the above given example spacing for 16 mm dia bar has been calculated, thus. In the. Number of Required Bars Formula = (Length of slab / spacing) + 1. Heavy loads. 2 m), regardless of steel grade. It is mainly to prevent upward bending moment near the joint. 8. = 2sqm/1sqm = 2nos. The Clear cover will be 25 mm (Top or Bottom) and the thickness of the slab will be 150 mm. 2and3 C. purchase orders, drawings, or per diems shall be done at the risk of those making such references or quotation. the maximum spacing between two secondary parallel bars in case of RCC Slab shall be 5d or 450 mm or whichever is less. 1 General== a 1 in direction of 11 • = a, in direction of 12 • angle between the axis of a strut and the bars in the i-th layer of reinforcement crossing that strut. 42D) – (1d x 4) – (2d x 2 (From BBS shape codes) d = diameter of the bar. 6. 12D Sq. Mild reinforcing bars shall have minimum clear spacing of at least 2 in. 2, with “S” assumed to be equal to the length between negative moment design sections. Only 1 D. For longitudinal reinforcement in beams. 1. 13. 2. 6. Distribution Reinforcement) Class B (Not Top Bars) J, NThe span requirement for the slabs is given by ACI Code 8. Distribution Bar. 50 8. The maximum spacing of reinforcement in slabs is 3d or 300mm(minimum of both). 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. 2Dead Load + 1. 3. 6% of the gross wall area for Grade 60 or Grade 40 bars, respectively. continuous slab – code coefficients-. 25 8 #5 12 6 6 2 4. of Main bars = (3000)/150 + 1. 12% of the overall sectional area. vapor retarders - some times referred to as vapor barriers, insulation, etc. Concrete cover to main reinforcing bars shall be provided per AASHTO Table 5. 4 Deck Overhangs for guidance on deck slab bars. The wires or bars will be lapped as follows. Unit weight formula for kg per metre = (D2/163) × L kg/m. 12% of cross-sectional area as distribution rebars as per. The maximum diameter of the reinforcing bar in a slab should not exceed 1/8th of the total thickness of the slab. , 1-hr. Important Points. 6 For two‐way slabs, maximum spacing of bars shall not exceed two times the slab thickness h nor 450 mm. slab to provide shear resistance. Step 2: Preliminary dimensioning. Spacing of bar = area of a bar * width of strip / area of reinforcement required = 78. Note * Spacing rationalised to suit punching shear links. 27. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. 2, 17. One Way Slab Reinforcement Detail. D. But even after that If d,provided < d,reqd, slab thickness is to be increased and check for deflection is to be satisfied. 2 SOLID SLABS SPANNING IN TWO DIRECTIONS When a slab is supported on all four of it sides it effectively spans in both directions, and it is sometimes more economical to design. 3. 10. 25*3. 5% or 0. 42d. No of Bars/m 2 = Factored Load / Pcr. You can design the two way slab using our android application. Distribution bars:-These bars are straight bars. For main bars, maximum spacing is restricted to 3 times effective depth or 300 mm whichever is smaller. 23 Total factored load = 6. We would like to show you a description here but the site won’t allow us. Hence, diameter of bar, thickness of slab, effective depth and spacing are co. Tech degree in Civil Engineering with six specializations, i. Distribution Bar. Longitudinal reinforcement should not be less than 0. 5 m as per IRC. The previous code that allowed up to Grade 520 was changed to Grade 550, and related regulations were modified. 3 Dowel bars The purpose of the dowel bar is to e ectively transfer the load between two concrete slabs and to keep the two slabs in same height. 3) For distribution bars, the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is smaller. 12% Gross area for HYSD bars, 0. Design ProcedureAllowable clear spacing of bars = 3d = 3(170) = 510 mm Actual clear spacing = 300 – 10 = 290 mm < 3d → ok Figure 3. advantage of the smaller lap lengths required for top slab bars. The spacing shall be less than five times the slab’s adequate depth, or 450 mm in the distribution bars. The maximum spacing between stirrups is smallest of the following provided that (V s <0. The cement content of concrete should be kept as low as possible by good grading of the aggregates. The code requires this value to be the minimum of these three values. As per ACI -The drop thickness should not be less than 100mm or (Thickness of slab)/4. =Eq. tangential spacing of legs of links, st max. Distribution Reinforcement bar: No of bars = total span/spacing = 2960 mm/200 mm = 15. 376Kgs For Floor slab -2 (One way slab) :-As per the above figure Floor slab -2 is a One way slab. where is the radius of the wheel load distribution in cm and is the slab thickness in cm. bending dimensions shall be measured as shown for appropriate standard shapes. 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. Is 1200 Important Point Part-1; IS Code for Civil Engineer [Q&a]. 890m. 78′ Say, 19′. 2. 5 In walls and one‐way slabs the maximum bar spacing shall not be more than three times the wall or slab thickness h nor 450 mm. 1. 1. 12. If the maximum diameter for. 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. 5 try 100 mm Dead load Slab weight = 2. Radius = 2. 6 in the following cases; In sections within a distance equal to 4 × thickness of wall above or below a beam or slab. Conclusion. Design the slab using the data given below; Purpose of building – Residential. If we increase the spacing beyond 200mm the column section buckling effect will occur. Two-Way. 13. Check resistance to moment transfer from column to slab . 3(1) of IS 456, is the lesser of 3(135) and 300 mm. 15% gross c/s of slab – for MS bars; 0. Number of bar = 1. 11. Assume 𝑓𝑐′ = 27. 6666666667 = 21 nos No of bars = 21nos . 3. The length of a distribution bar in west side is the same as the east side. Maximum spacing of bars for slabs • Main bars: 3h ≤ 400mm (in areas of concentrated loads 2h ≤ 250mm) • Secondary bars: 3. 10. Base slab width b= 0. 1. dowel misalignment levels of less than 1 in. 3. 1 or the bottom bars required by 8. Before calculating the cutting length, we need to calculate each part length of chair bar. . 67’ Weight of Distribution Bars = d 2 /52. t + d Lsy. Diameter of the Main reinforcement bars = d m = 12mm. The ACI 318-19 provides a number of requirements regarding slab thickness, concrete cover, and reinforcement ratio which facilitate the design process. To distribute the superimposed load to the main bar. No of Bars/m 2 = Factored Load / Pcr. 5. The diameter of the reinforcements and the spacing of bars are to be used according to the (cls. Select the correct answer using the codes given below: A. 0m from the fixed end. Refer to Section 5. The maximum anchor nominal diameter is 5 / 8 inch (16 mm). The new formulas are more complex and consider more parameters, such as bridge length and. 667’ x 40. Assume 𝑓𝑐′ = 27. Spacing of bar supports depends upon the size of the reinforcing bar being. If shear reinforcement is required for in-plane strength, s shall not exceed the smallest of 3h, 18 in. Now, we will calculate the length of the three parts of the chair bar separately. 1—General 8. 2 (6) Beams: the maximum longitudinal spacing between shear assemblies s l,max; 9. Now we have to calculate the depth from maximum moment values. 1 Purchaser’s tests of steel reinforcing bars 28 Section 6 Methods of testing 32 6. 5. Load Distribution. 21. 5. 4. , addi-tional bonded shrinkage and temperature reinforcement conforming to 7. 1000 1500 2000. 1 and 24. Sub-slab details (i. Use bar support in order to maintain the space between bars at the top and bottom and then the distance will be correct. 1000 1500 2000. Distribution of Main Bars. 2 to read as follows:In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. 3 Direct supply of steel reinforcing bars to site by QA Manufacturer 27 Section 5 Purchasers testing 28 5. (c) Distribution. (b) Slabs where Grade 60 deformed bars or welded-wire fabric (plain or deformed) are used: 0. 7. 3. In this kind of. 8. Placed at a longer. Cutting length= 9000 – 2 x 50 =8900 mm =8. Ensure that the return bars at the edge of the slab are a minimum of ¼ (15%) of the length of the adjoining span. 1. 12% of the total cross sectional area , when HYSD bars Fe415 are used. Number of Main Bars = (Length of Longer Side / Spacing) + 1 =. The spacing of the bars The length of a distribution bar on the south side will be the same as the north side. the criteria of max spacing is 3 times the effective depth or 45 cms whichever is smaller; Maximum diameter of bar in slab will not exceed. 6. 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. 2. 67 m, the slab depth for the voided slabs ranged from 10 inches to 16. As per IS 456 : 2000, Minimum percentage of reinforcement: 0. 4. 0104 Ai. The main conclusions can be summarized as follows: • The proposed method gives a good estimate for crack. The Distribution bars will be 8 mm in diameter with 125 mm c/c spacing. 3. 3. 12% gross c/s of slab – for HYSD bars; Spacing of distribution bars. To calculate: Spacing of replaced 12mm. Concrete floor slabs on grade are subjected to aIn steel reinforcement binding wire required is 8 kg per MT. Step 2: Calculate cutting length of main bars and distribution bars. 7. Two way slab building. Maximum Reinforcement Ratio:In this video, you will learn the Spacing between the Main and Distribution steel bar. 6. 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. SECTION 5: CONCRETE STRUCTURES 5-5. Reinforce concrete for a 5-inch thick concrete slab: For a 5-inch thick slab, #4 (1/2-inch diameter) rebar is commonly used. 0m from the fixed end. 2. Given Data: Height of footing = 600 mm. the square of the thicker slab when f=0. 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. 2(5)4. of Main bars = (Width of Slab/Spacing) + 1. thick slab will increase the potential for random or out-of. Clause 6. spacing of bar/prestressing strand etc. Calculation of area of steel. 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. 2 Use Φ12 bar c/c 250mm 2. 4 bar at the top and the bottom. Use #4 bars at 25-inch spacings center to center each way, As = 0. Joints are provided in concrete pavements to control. 1. 3. ? 1. Cutting Length: = total length — 2 x clear cover = 4000 - 2 x 20 = 3960 mm or 3. The span requirement for the slabs is given by ACI Code 8. 75H for surcharged wall. Calculate The Cutting Length of the Chairs Bar Given Data. cm. Minimum number of bars. As = 0. áTie the bars at the top and the bottom irrespectively. 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. 5 bar is permitted to be located at either the top of the slab or bottom of the footing. Thickness of Slab = 0. 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. are called concrete. 3. 11. For Min Steel: 3d ——— Where. 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. Number of Distribution Bars = Lx / spacing + 1 = 3000/150 + 1 = 21 nos. 5. 4 and shall have a total area of not less than 0. 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. The size and spacing of S1 and S2 bars shall be determined by design. 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. 4. The distribution bars are arranged to retain the mesh in perfect place and sustain the center to center c/c, bars. 2: Alternate method for showing two-way slab reinforcement reinforcing bars should be clearly scheduled on the drawings. Basically slab is the horizontal member which is rests on the beam section. To find the Bar Bending Schedule for Slab we use the following formula, No. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. 60. The maximum diameter of the reinforcement bars in R. 5. 1. 5. Lower part bar will be worked by maintaining cover with spacer. , see 10. 1. Check for Cracking. 7. 7. 9 m = 3. 2 of ACI 318-11, it should be clearly denoted on the structural drawings. Slabs - - - maximum spacing is 3*deff or 300mm whichever less side ) of the deformed bar ( see Note ) NOTE - In accordance with IS : 1139-1966. 1. 8% and more than 6% of gross C/S. 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. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. 9. The manual design process included the reinforcement calculation for the main bars and distribution bars as per the considerations and as per the problem statement. 7. Unbonded Cross Sections" for discussion. (1) Deformed steel bars will be overlapped for a distance of at least 24 bar diameters measured from the tip of one bar to the tip of the other bar. e. 6H, and 0. iv) Detrmine Sapcing of bars at critical section based on designed value of Ast by selecting appropriate bar dia. Provided at the top of the slab. 9, page 341. Since diameter of bar = 10 mm. 5 inches, and the transverse bars must be fully developed in grouted masonry at the point where they cross the lapped reinforcement. 3.