1. Spacing of main reinforcement bars = 1000/ [A st,req / Area of single bar] = 1000/[660 / 78. To firmly hold the main bars in their. They ensure that the load is not concentrated in one area, which could cause cracking or failure. 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. where is the radius of the wheel load distribution in cm and is the slab thickness in cm. 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. 667’ x 40. 2 SlabsContinuous OverSupports 24. Roof drainage system (Adapted from the International Code Council). The distribution bars’ primary function is evenly distributing the load across the slab. 9) Prepare bar bending. Tech. 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. The ACI 318-19 provides a number of requirements regarding slab thickness, concrete cover, and reinforcement ratio which facilitate the design process. For distribution bars, the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is smaller. Distribution steel: 0. 3 Required Strength 4-2. Exceptions: 1. Side clear cover of slab 25 mm; Thickness of slab is. The maximum spacing of minimum steel (distribution bars) is the lesser of 5(135) and 450 mm. 1 mm) and maximum panel span of 8 feet (2438 mm) shall be permitted for opening protection in buildings with a mean roof height of 33 feet (10 058 mm) or less that are classified as a Group R-3 or R-4 occupancy. 2. 5 in Y-axis Distribution area 3. 1. Slab steel bar not less than 10mm dia. àIn case the thickness of slab is 120mm, the height of bent bar should be 60mm. 3. 5 mm 2. b) In partially prestressed superstructure: In tension zone it shall not be less than that calculated as per Sections 12 and/or 16 (whichever is higher) of IRC:112. If a closer spacing of bars is required at the columns, as per Section 13. 3. for interior walls. Step 1. Minimum clear cover to reinforcements in slab depends on the durability criteria and this is. The distribution bars number 17 in total. 6. 5. There are also new provisions for integrity reinforcement. Step 5 – Calculation of Steel Weight. 5. Distribution Bar. 6 𝑀𝑃𝑎. The spacing shall be less than five times the slab’s adequate depth, or 450 mm in the distribution bars. 11*12 in c/c Step 6 : Temperature and Shrinkage ReinforcementWeight of distribution of 8 mm dia steel bar = 33. Whereas, Factored Load = 1. A diagonal crack that might result in shear failure, as suggested in Fig. 6. e. Step 1. 5. 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. Length of waist slab= L. As per IS 456 : 2000, Minimum percentage of reinforcement: 0. 1. 75 m. The length of a distribution bar on the south side will be the same as the north side. For Edge Spans : Static Mom. FIrst, find number of rods required for main reinforcement and distribution. VARIATION AMONG BETWEEN MAIN BARS AND DISTRIBUTION BARS: 1. 25*3. 7. 2 Use Φ12 bar c/c 250mm 2. Wall Load Per Running Meter. Weight of Distribution Bar= d²/162. 12% of high yield. Development Length (Ld) = 40d. 00 P Flag question The maximum spacing of the distribution bar in the one-way slab must be 450 mm or less than Select one: : a. Minimum S&T reinforcement quantities required by ACI 350-01 and11. No of Bars/m 2 = Factored Load / Pcr. 2. #IS456Explanation#SpacingofReinforcement#IESGATEWizIn this Video Part-45,detailed discussion of IS 456-2000 provisions of Spacing of Reinforcement Bars ha. The ACI 318-19 provides a number of requirements regarding slab thickness, concrete cover, and reinforcement ratio which facilitate the design process. Provided spacings, therefore, satisfy the requirements. >EAST side. 1 for minimum thickness of non-prestressed two-way slabs without interior beams is revised to include Grade 550. Slab steel bar spacing maximum 150mm c/c. Note * rationalise centre of bars in column strips T2 and B2 to 175 mm centres to suit punching shear links. 76 Slab designation: CS1 Check if one-way or two-way slab 1 Slab is one way since it is catilever slab Minimum slab thickness min t = 69. 2. April 2, 2023 May 25,. 2 Spacing of longitudinal reinforcement 11. 60. All values are taken except ‘D’ in the above formula. 9. 2 – Spacing of tendons shall not exceed 6 feet. 5. 2 of ACI 318-11, it should be clearly denoted on the structural drawings. 3. The maximum diameter of the reinforcement bars in R. Bar Bending Schedule Of Slab (Two Way) Ly/Lx = Longer span/Shorter span = 5000/3000 = 1. Thickness of Slab – 150 mm. The minimum and maximum spacing reinforcement in concrete structural members such as beams and slabs. The thickness of Slab – 150 mm. the joint spacing should be 24 to 30 times the pavement thickness with a maximum spacing of 15 ft (4. How to calculate reinforcement bar spacing How to calculate Minimum Bar Spacing for Bundle Bars in Cast-in Place Concrete as per AASHTO provisions. No. Sub-Grade and. If a closer spacing of bars is required at the columns, as per Section 13. 6. 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. and the clear spacing between the bottom bars a = 60 mm. 2) For main bars, maximum spacing is restricted to 3 times effective depth or 300. Top & bottom distribution bar dia. Concentrated reinforcement is a fixed number of bars over a parallelogram area. 3. 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. 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. 9. 3. Always main bar use in shorter span. 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. and 𝑓𝑦 = 276 𝑀𝑃𝑎 for main and temperature bars. 7. Whichever is smaller,. 6—Factors affecting the construction load distribution 3. 1. 3 Slabs Monolithic with Supports 24. W = 3. 7. EXAMPLE PROBLEM 1. 7—Reinforcement detailing 8. of chair bars = Area of structural reinforcement in sqm / chair bar per sqm. The main bars will be 12 mm in diameter @100 mm c/c spacing. 4. 3. 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. 11. 2 and 26. Base slab width b= 0. 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. 6. 1 and 24. Here we have to calculate the number of main bar and distribution bar. Calculation: The spacing of replaced bar is calculated by the formula [(D1) ² (D2) ²] = [S1 S2] Where,We would like to show you a description here but the site won’t allow us. Diameter of main bar=10mm. 1. 2. 3(d) and 17. For Min Steel: 3d ——— Where. 26. 1) The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. Common rebar sizes range from #3 to #6 for slab footings, with #4 being the most commonly used. 3. 7. 85MPa) was added as a code requirement. In general we use 5 inch (125mm) thick slab, if thickness of slab is 125mm,then maximum diameter of bar used in. Additionally, the clear space between the transverse bars and lapped bars may not exceed 1. Calculated area; 5 x d; 450mm; Diameter of bars. joint spacing greater than 50 ft (15. ' = 1536 sq mm. The diameter of the bars varies from 8mm to 14mm and should not exceed 1/8 th of the overall depth of. 4 times effective depthThe precast concrete product, which is used to provide the necessary covers or spacing for the reinforcement bars from the formwork, in all the RCC structures like slab, column, beam, footing, etc. 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. The maximum spacing of bars shall not exceed. Considering M20 grade of concrete and Fe 500 steel of diameter of 10 mm. 96 x 1000 / 1536 = 130. The Distribution bars will be 8 mm in diameter @125mm c/c spacing. Joist system relative dimensions, slab thickness, rib width and spacing between ribs are specified in ACI 318-05, Section 8. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. The main reinforcement of an RC slab consists of 10 mm bars at 10 cm spacing. 19 or greater, the minimum concrete cover is 5 cm. Spacing should not exceed smaller these two values. Mild reinforcing bars shall have minimum clear spacing of at least 2 in. 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. The Clear cover will be 25 mm (Top or Bottom) and the thickness of the slab will be 150 mm. 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. The Main bars will be 12 mm in diameter with 100 mm c/c spacing. 1. f. The maximum clear spacing between parallel bars shall not be more than 1 N-6O. 4. of Main bars = (3000)/150 + 1. 230m. 1123 mm. Clear span of the two way slab = 5000 mm. 2, 17. Spacing of chairs should be per 1 m or 1 no. 89 M. If shear reinforcement is required for in-plane strength, spacing of longitudinal reinforcement shall not exceed l w /3. a = axial spacing of the bar for calculating the lap length (ci. Calculate cutting length: calculate the required number of bars for both directions. Concrete cover to main reinforcing bars shall be provided per AASHTO Table 5. of Main bars = (Width of Slab/Spacing) + 1. Minimum number of bars. M =. The clear cover is 30 mm ( top to bottom ) and the thickness of the slab is 150 mm. 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. 8. 5 m. 2(5)In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. 8. 0020. , 300 mm. Hence, diameter of bar, thickness of slab, effective depth and spacing are co. 2, The diameter of reinforcing bars shall not exceed one-eighth of the total thickness of the slab. 11. 1. 091 = 300. 7. 4. Minimum requirement in slab : As per clause 26. As always, local service records are the best guide for determining trans verse joint. 7. 1 or the bottom bars required by 8. MOM-X – Longitudinal moment, corresponding to which LONG. 1: The prime functional requirement of a joint is to cater for movements with very low resistance or with no resistance at all. Beams = Self Weight per running meter. Total Length of Distribution Bars = 19. Q) Design a reinforced concrete slab for a room of clear dimension 4-meter x 5 meters. According to ACI Code 7. b) Slab depth does not exceed 200 mm when the steel grade is 460. 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. (14) Step Find the load transfer capacities , , and of single dowel bar with the. the total length of the leg is 2×spacing +50. b. 2 – Spacing of tendons shall not exceed 6 feet. One Way Slab Bar Bending Schedule Calculation. 2(5)4. Different codes have different formulas to calculate crack spacing and width developed in flexural members. 8. steel bars. Collectors, Chords and ConnectionsIS Code. The cross‐sectional area of one N28 bar is As = 620 mm2 and with N12 stirrups at 150 mm centres, Atr = 110 mm2. According to ACI Code 7. 4. Minimum Bar SpacingAs per AASHTO LRFD, section 5. That is: 19′. 1% of the slab cross-sectional area) through sawcut contraction joints in combination with the recommended joint spacing. 3 or larger placed within the last 8 inches of each end of the lap (Figure 3). What Is The Maximum Bar Spacing In Reinforced Beams According To IS 456? Normally this spacing will be as mentioned below: · For beams, these distances are 300 mm, 180 mm and 150 mm for grades of main reinforcement of Fe 250, Fe 415 and Fe 500, respectively. Lower part bar will be worked by maintaining cover with spacer. 5 bar is permitted to be located at either the top of the slab or bottom of the footing. 9, page 341. Base slab width b= 0. 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. bar per corner 10mm Ø vert. The main conclusions can be summarized as follows: • The proposed method gives a good estimate for crack. 3. It is a two way slab. 2. Weight of Distribution Bar= (8)²/162. 1 specifies the requirements of ACI 7. Two way slab building. Main Steel Bars. 4. Unit weight formula for kg per metre = (D2/163) × L kg/m. 1-4. Concrete moisture conditions and drying rate. As per ACI -The drop thickness should not be less than 100mm or (Thickness of slab)/4. 2 (6) Beams: the maximum longitudinal spacing between shear assemblies s l,max; 9. 6. Designing and drawing of flat slab with the help of i. 1. 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. Number of Required Bars Formula = (Length of slab / spacing) + 1. 1—General 8. The design of one-way slab is simple and can be carried out easily. As many of these requirements would need to be repeated in Chapters 3 through 14, placing such requirements in only one location eliminates code development coordination issues associated with the same requirement in multiple locations. 2 times effective depth b. Slabs - - - maximum spacing is 3*deff or 300mm whichever less side ) of the deformed bar ( see Note ) NOTE - In accordance with IS : 1139-1966. 10. 5% steel (continually reinforced) as described in Section 8. 2 Maximum Distance between Bars in Tension. 2 mm. The number of bars is 50. 3. = 2sqm/1sqm = 2nos. 5—Application of the simplified method 3. for exterior walls or 30 in. Placed at a longer. No of main. TWO WAY SLAB DESIGN SPREADSHEET:Fig 10: Reinforcement of a slab. spacing in plates and two-way slabs with concrete covers. What is the maximum spacing of a distribution reinforcement to be used in a one way slab as per IS 456? b. e. 6 in the following cases; In sections within a distance equal to 4 × thickness of wall above or below a beam or slab. BS EN 1992-1-1 Annex 1 1. No. 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. 3. 3. Curtailment of bars in slabs Curtailment of bars is. C. ([DPSOH ± 'HWHUPLQDWLRQ RI Seismic Forces: Diaphragms of %XLOGLQJ Chapter 4 One-way Slabs 4. 2, also includes guidance on achieving enhanced aggregate interlock by continuing a small percentage of deformed reinforcement (0. Adequacy of curing. Concrete moisture conditions and drying rate. Lesser dimension bars are used. Note * Spacing rationalised to suit punching shear links. No. 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. Number of bar = total width /spacing +1. 2. In both cases, the minimum bar areas are equal to 0. 4 Water 5. Eurocode 2 section 9. The “D” bars shown in the tables conform to Article 9. 2. The slab is not. 26. (c) Deep beams in accordance with 9. The clear cover will be 25 mm(Top or Bottom) and the thickness of the slab is 150 mm. To distribute the superimposed load to the main bar. The maximum spacing of bars shall not exceed. The cross‐sectional area of one N28 bar is As = 620 mm2 and with N12 stirrups at 150 mm centres, Atr = 110 mm2. For preparing the bar bending schedule according to the given data. Thus, the requirement threshold of 125psi (0. Distribution Reinforcement) Class B (Not Top Bars) J, NThe span requirement for the slabs is given by ACI Code 8. Calculation of area of steel. The AASHTO-LFD formulas are based on the girder spacing only and are usually presented as S/D, where S is the spacing and D is a constant based on the bridge type. Unit weight for feet per metre = (D2/ 533). Crack Control – when crack widths are not checked by calculations No Further Checked Required. 3. slabs) or integral with slab with depth greater of 2. steel bar use Top Side +28 Nos Steel use. 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. Other notations, wherever used, areQuick guide to design of one way slab – with IS Code 456:2000. Weight of Distribution Bar for Waist Slab. Thickness of Slab = 0. 896 x Total Length (where d is in # Nos. Important Point: As per IS 456:2000, the limit on minimum reinforcement along either direction has been specified. Distribution bars are 8 mm in diameter @ 150 mm centre to centre spacing. The continuous vertical bar required beside an opening is permitted to substitute for one of the two No. the constant value of 50. 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. 7. 6% of the gross wall area for Grade 60 or Grade 40 bars, respectively. Head ( E ): The length of the head = [(2nos. Provide main reinforcement of 10 mm diameter bars at 120 mm c/c. for industrial slabs that carry distribution. Practical considerations of one-way slab • Spacing shall be between 150-200 mm (main bars) • Spacing shall be between 150-300 mm (distribution bars)Bar Bending Schedule for Two Way Slab. (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. 2. it's a tool to maintain the spacing between two separate layers of slabs, footing etc. 67’ Weight of Distribution Bars = d 2 /52. #IScodes #Concrete #Concretetechnology Recent & Related Videos Concrete. Bar schedule for Slab; Table 3 : Bar schedule for SlabArea of single bar = (3. dia. 1 Spread Box BeamsA. 8. 150m = 150 mm. 12% of the total cross sectional area , when HYSD bars Fe415 are used. 42d. According to direct design, the balanced load, W1, and the effective prestressing, F, in a one-way slab or the beam supports for one-way slabs can be computed as t _ 48kBW + 8k f (L (3) Wl — 1 + 48kB F, = 72BW L2 + 12 f t2 (4) t(1 + 48kB) where B is the moment coefficient, M = BWL2, depending on the slabDesign of 2 way slab as per IS code. Provided to resist the shear stress and cracks. shall be the lesser of (i) five times the effective depth, or (ii) 450 mm. 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. 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. The length of a distribution bar in west side is the same as the east side. Lesser dimension bars are used. Anchor bolts are located a minimum of 1 3 / 4 inches (45 mm) from the edge of the concrete parallel to the length of the wood sill plate. 2. Spacing: ϕ8 mm: ϕ10 mm: ϕ12 mm: ϕ16 mm: ϕ20 mm: 100: 502 : 785: 1130: 2010: 3141: 125: 402:. Provide 0. 6 For two‐way slabs, maximum spacing of bars shall not exceed two times the slab thickness h nor 450 mm. 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. 5. 6. For Edge Spans : Static Mom. 2 to read as follows:Top & bottom distribution bar dia. 6. Larger areas, lower loads, and higher seismic zones. Is 1200 Important Point Part-1; IS Code for Civil Engineer [Q&a]. The slab edge insulation for heated slabs shall not be required to extend below the slab. e. The slab requires 51 main bars. The maximum clear spacing between parallel bars shall not be more than 1 N-6O. >EAST side. 1 QA Stockist’s certification of steel reinforcing bars 25 4. . 200= 6. Important Point: As per IS 456:2000, the limit on minimum reinforcement along either direction has been specified. The wires or bars will be lapped as follows. Design size and spacing of dowel bars at an expansion joint of concrete pavement of thickness 20 cm. 3. Provided at the bottom of the slab. 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. The following minimum limitations relating to various structural components shall be followed: Thickness of top flange : 100 mm. Weight of Distribution Bar=64/162. C. 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. 5] = 120 mm c/c. 3. Given, Cranked bars or Main bar of diameter 16 mm and center to center spacing 150 mm. Assume diameter of bars and calculate spacing of bars. 10. And, in compression zone, same as in (a) above.