equal to ( C < 2. 15m. Tayabji (1986) identified the following categories of dowelmillimetres and N represents the identification number of the bar/bars given consecutively. 1. 15% of the gross cross-sectional area if mild steel bars are used. 6. Clear Cover = 20 mm. For the cranked bars near the supports at the top of the slab distribution bars of same size and same spacing are provided below the top bars. 2 Spacing of longitudinal reinforcement 11. Step 1- Calculation of Numbers of Bars. Number of Main Bar & Distribution Bar: First, we have to calculate the number of bar required for the slabs. Figure 3. 2. EXAMPLE: Suppose we have a one-way slab, which has a length of 5 m or a width of 2 m (clear span). 5. 5φVc except for the following cases: A. Practical considerations of one-way slab • Spacing shall be between 150-200 mm (main bars) • Spacing shall be between 150-300 mm (distribution bars) • Max. Provided at the top of the slab. Main Steel – 3d or 300 mm whichever is smaller. 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. 4—Construction load distribution 3. As per IS code, the minimum grade of concrete for the design of a Pre-tensioned concrete structure is:-M20; M25; M40; M30;Cutting Length of Foundation Distribution Bar. , i. than that calculated as per Sections 12 and/or 16 (whichever is higher) of IRC:112. A = roof area in square feet drained by the drainage system. 5. Rebar steel will be calculated for the bending moments “Mx” and “My. 8. Maximum spacing between Individual Bars: The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. Minimum distribution reinforcement steel (for TOR Steel) shall be 0. 2 BS 8110-1:1997) Width of the beam = 500mm = 0. Mild reinforcing bars shall have minimum clear spacing of at least 2 in. 5. 6. 31kg says 35kg. The maximum spacing of reinforcement in slabs is 3d or 300mm(minimum of both). 66 < 2. Length of the Slab = 5 m = 5000 mm. Maximum spacing of tension bars (all slabs) In accordance with clause 7. Max. Important Point: As per IS 456:2000, the limit on minimum reinforcement along either direction has been specified. Bar Spacing: The lateral spacing of the flexural bars should not exceed 3 times the thickness h or 18 inches according to ACI code 7. 6. 304. The minimum and maximum spacing reinforcement in concrete structural members such as beams and slabs. 3. 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. bars at every 3 layers of chb finished surface corner wall detail 1 - 10mm Ø vert. 3. 9. This smaller amount of reinforcement0. 9. 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 Spacing s of transverse bars in precast walls shall not exceed the. The maximum spacing between stirrups is smallest of the following provided that (V s <0. Distribution bars are provided in the longer span direction. 3. 5. Distribution bars:-These bars are straight bars. 2, can form no closer to the facesee table 3 for spacing. Distribution bars are provided perpendicularly with the top of the main bar. (a) for a distance equal to the larger lateral dimension of the column above and below a beam or slab, andThe complete column design process as per IS code is determined by using below 3 basic formulas. Calculate cutting length: calculate the required number of bars for both directions. Step 2: Preliminary dimensioning. TWO WAY SLAB DESIGN SPREADSHEET:Fig 10: Reinforcement of a slab. advantage of the smaller lap lengths required for top slab bars. Given Data: Height of footing = 600 mm. The slab has to carry a live load of 4 KN per meter square. 2—Construction load factorsThe diameter of the main bar should not be less than 8mm for the HYSD bar and 10mm for plain bars. And depth of check is determined as per IS 456 standards. Spacing s of longitudinal bars in precast walls shall not exceed the lesser of (a) and (b): (a) 5h. Basically slab is the horizontal member which is rests on the beam section. 11*12 in c/c Step 6 : Temperature and Shrinkage ReinforcementWeight of distribution of 8 mm dia steel bar = 33. In this article I will explain you complete slab design as per IS 456 code by using manual method. Generally # 3 or # 4 bars are used for slab main reinforcement. In both cases, the minimum bar areas are equal to 0. of Main bars = (3000)/150 + 1. The minimum percentage of reinforcement is 0. Main bar = 12mm@150mm c/c. 2. 6. 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. Anchor bolts are embedded into concrete a minimum of 7 inches (178 mm). f. 6. Step 2: Calculation of cutting length ( for main bars and distribution bars) Cutting length of main bar = Clear span of slab + (2 × Development Length) ( 2 × D e v e l o p m e n t L e n g t h) + Inclined Length - Bend Length. 460/2=1. For slabs less than 200 mm thick the following maximum spacing rules apply: For the principal reinforcement: 3h but not more than 400 mm. R-5 insulation shall be provided under the full slab area of a heated slab in addition to the required slab edge insulation R-value for slabs. For distribution bars the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is less. × c/c distance between the top distribution bar) + (extra length on either side of the top distribution bar)]Calculate the nos’ of facet rebar. This chapter shall apply to the design of nonprestressed and prestressed beams, including: (a) Composite beams of concrete elements constructed in separate placements but connected so that all elements resist loads as a unit. 7. Dia of Bar to be provided 'd' = 16 mm (round bar) Area of cross-section of 1 bar = 0. 4 bars in the middle third of the footing depth. ' = 1536 sq mm. 1. 75H for surcharged wall Base slab thickness= H/10 to H/14 Toe projection= (1/ 3-1/4) Base width Behaviour or structural action and design All the three elements namely stem, toe and heel acts as cantilever slabs and hence the design 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. 9 Factored loads Factored dead load = 3. , nonskewed) bridges only. For concrete cast against and permanently. Ld = Development length of the bar. ( IS: 456-2000 ). 1. Basic considerations. The Distribution bars will be 8 mm in diameter with 125 mm c/c spacing. 4. Full bond Full bond h/2 Filler Figure 15:3: Contraction joint 15. bar. 7. Radius = 2. 2. 1 QA Stockist’s certification of steel reinforcing bars 25 4. thick slab, the maximum joint spacing should be limited to 12 to 15 ft. 2. 3. The direction of the main bars (T1 and B1) in a flat slab system depends on various design factors such as the span length, load distribution, structural efficiency, and code requirements. 1000 1500 2000. The code makes it explicit that the diameters of the skin bars are not involved in determining the spacing of this reinforcement. 8. 1% steel allows sawed contraction. 4 bars in the middle third of the footing depth. 1: The prime functional requirement of a joint is to cater for movements with very low resistance or with no resistance at all. and 𝑓𝑦 = 276 𝑀𝑃𝑎 for main and temperature bars. 3. however with a maximum spacing of 4. For 8 mm diameter bar 7 inches to 9 inches center to center c/c. 1 given below by the ACI 318-14 code. Calculation of the loads. steel bar use Top Side +28 Nos Steel use. Thickness of Slab = 0. That is: 19′. , 300 mm. Cover block use 15 to 20mm. 27. the total length of the leg is 2×spacing +50. However, it is not a code, so many engineers do use portions of ACI 318 on their projects. 7. 2. 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] = 120 mm c/c. Step 1. 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. The distribution bars should be (2000- 2 x 25) /125 + 1. 6—Reinforcement limits 8. 3. 12. Refer to EN 1994-2, Clauses 6. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. 7 For temperature steel only, maximum spacing shall not exceed five times the slab thickness h nor 450. 75 m. The shear resistance in a R. Difference Between Main Bars And Distribution Bars: Main reinforcement bar is normally used at the bottom of the slab. M. Opposite length of bar = 2950. The Distribution bars will be 8 mm in diameter with 125 mm c/c spacing. Minimum spacing for distribution bars is, (1) 5d = 5 X 76 = 380 mm (2) 450 mm . Lower part bar will be worked by maintaining cover with spacer. b) Slab depth does not exceed 200 mm when the steel grade is 460. Spacing: ϕ8 mm: ϕ10 mm: ϕ12 mm: ϕ16 mm: ϕ20 mm: 100: 502 : 785: 1130: 2010: 3141: 125: 402:. There are no SHGC requirements in the Marine Zone. Always main bar use in shorter span. e. Minimum Reinforcement Ratio in Slabs. iv) Detrmine Sapcing of bars at critical section based on designed value of Ast by selecting appropriate bar dia. The size and spacing of S1 and S2 bars shall be determined by design. Concrete moisture conditions and drying rate. 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. 9. No of Bars/m 2 = Factored Load / Pcr. The distribution bars provide the following functions in slab construction: 1. Note * rationalise centre of bars in column strips T2 and B2 to 175 mm centres to suit punching shear links. 2 d t kips in. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. 8. the square of the thicker slab when f=0. where is the radius of the wheel load distribution in cm and is the slab thickness in cm. Slab steel bar spacing maximum 150mm c/c. Fig. of chair bars = Area of structural reinforcement in sqm / chair bar per sqm. three times the effective depth of solid slab or; 300 mm; whichever is smaller. 1. (b) Horizontal reinforcement at least 0. It is a useful reference for engineers, planners and contractors involved in bridge construction. 347. Alternative reinforcing bar sizes and spacings having an equivalent cross-sectional area of reinforcement per lineal foot of wall shall be permitted provided the spacing of the reinforcement does not exceed 72 inches in Seismic Design Categories A, B and C, and 48 inches in Seismic Design Categories D 0, D 1 and D 2. Calculation of effective depth. 3. and : 1786-19667, the nominal size of the deformed bar is equivalent to the diameter or side of a plain bar having the same weight per metre run as the deformed bar. 7. 167 for 15% redistribution. The minimum spacing between the two bars can be about 50–75 mm. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. 9. The wires or bars will be lapped as follows. Collectors, Chords and ConnectionsIS Code. 1. 3 Slabs-on-ground with turned-down footings. 18D sq. 12 % of the gross area if the HYSD bar (Fe415) is used. 6. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. 150m = 150 mm. Reinforcing Bars for Crack Control 6-33 Distribution of Tension Reinforcement in. 93 m 2 ) = 469. 5 and 6. Design the slab using the data given below; Purpose of building – Residential. Design size and spacing of dowel bars at an expansion joint of concrete pavement of thickness 20 cm. design wheel load 4000 kg. Slab steel bar not less than 10mm dia. Spacing =150mm. If shear reinforcement is required for in-plane strength, s shall not exceed the smallest of 3h, 18 in. spacing of bar/prestressing strand etc. 5. The maximum anchor nominal diameter is 5 / 8 inch (16 mm). 3. = 16mm, spacing @ 150 c/c. Concrete Slab Design ProcedureSteel reinforcements can be use, however with a maximum spacing of 4. The slab edge insulation for heated slabs shall not be required to extend below the slab. Step 1: – Calculate numbers of distribution rods. The distribution bars’ primary function is evenly distributing the load across the slab. Fig. 5 bar is permitted to be located at either the top of the slab or bottom of the footing. Total Length of Distribution Bars = 786. If a closer spacing of bars is required at the columns, as per Section 13. Head ( E ): The length of the head = [(2nos. dia. Weight of the bar as per their length and diameter by following the Formula: –. The spacing of distribution bar should not be greater than 5 times the effective thickness of slab or 450mm whichever is smaller. 6. The distribution bars number 17 in total. 4—Openings in slab systems 8. 5. Bar crank. Length of waist slab= L. 890m. 6. Clear cover = 25mm (top and bottom ) Thickness = 150mm. Distribution bar = 8mm@150mm c/c. Assume 𝑓𝑐′ = 27. Distribution Bar = 1800 -2 (75) ÷ 150 +1. Provide 0. 3. However, in some cases, 10mm dia bars are taken for the floor slab, when there is no extra external load other than reinforcement mesh load. and 𝑓𝑦 = 276 𝑀𝑃𝑎 for main and temperature bars. 140 M. 3% (100As/bd < 0. 3. Spacing (feet) Deck Slab Thickness, T (inches) Transverse Bar Size and Maximum Bar Spacing, S (inches) F dimension (inches) #5 “D” Bars per Bay (quantity) #4 “G” Bars per Bay (quantity) Bar Size S 4. 78′ Say, 19′ >WEST side. 3 of IS 456). 16. 10 cm; 12 cm; 14. Check for Cracking. 25*3. The Clear. 42d. 18D sq. 12. Note that required A s must be furnished in each direction. 1. Business, Economics, and Finance. Reinforcement chairs should be made with a minimum of 12 mm bar. The number of bars is 50. 0m from the fixed end. Weight of rod per meter length = d 2 /162 where. Adequacy of curing. 3. 23 Total factored load = 6. bar per corner 10mm Ø vert. 6. Placed at a longer span. 15 % of the gross area if a mild steel bar is used. Height of block wall = 2. Cryptocritical section of the slab is just outside the outside edge of the beam supporting the slab. of distribution bars = Ly/Spacing + 1 = 2000/150 +1 = 14. 1 of IS 456:2000, the reinforcement in either direction ,in slabs shall not be less than 0. Distribution bars placed on top of the main bar. 8. As per ACI Code, In slab, minimum reinforcement shall be 0. rainfall intensity in inches per hour for the building location specified in the plumbing code. Spacing should not exceed smaller these two values. The main conclusions can be summarized as follows: • The proposed method gives a good estimate for crack. 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. Minimum S&T reinforcement quantities required by ACI 350-01 and11. The term "standard hook" as used in this Code shall mean one of the following: (a) 180o. The code itself suggests that the diameters can be #3, #4 and #5. 11in2) Spacing = As 0. 1. cm. Ex. 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. 2 or 8. Step 4 – Extra Top Bar. 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. 2—Flexural reinforcement spacing 8. Number of Main Bars = (Length of Longer Side / Spacing) + 1 =. 1. The maximum diameter of the reinforcement bars in R. Heavy loads. 3. 4 must be met, and max. 6. 25𝑚𝑚 𝐴𝑠 415. A minimum of three bars evenly placed in the lap length is required. Provided spacings, therefore, satisfy the requirements. 5 bar is permitted to be located at either the top of the slab or bottom of the footing. 25. 17 The design of one-way slab is simple and can be carried out easily. Distribution Bar. So, Provided area of steel reinforcement, Ast=2416 mm 2. slabs) or. As = 0. 2. Development Length (Ld) = 40d. April 2, 2023 May 25,. 34 kg ——– (1) Section 1 Total = 33. Table 1. Clear span of the two way slab = 5000 mm. Use #4 bars at 25-inch spacings center to center each way, As = 0. >EAST side. For example let us consider a building which is having 120mm thickness of slab, for that particular structure we need to take maximum reinforcement bar diameter is (1/8) of 120mm which is 15mm. slabs) or integral with slab with depth greater of 2. 5, the lateral spacing of the flexural bars should not exceed three times the thickness of 18 inches. The minimum percentage of reinforcement is 0. 5d = 5 * 130 = 650 mm. 00mm Bottom Footing Clear Cover (F, CL). 150m = 150 mm. , see 10. 4 and shall have a total area of not less than 0. No. are called concrete. 3(1) of IS 456, is the lesser of 3(135) and 300 mm. 3, the maximum spac- 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. 6% of the gross wall area for Grade 60 or Grade 40 bars, respectively. 3. This reinforcement is reported in terms of area required per unit width of slab. 1 for minimum thickness of non-prestressed two-way slabs without interior beams is revised to include Grade 550. 896 x Total Length (where d is in # Nos. 4. Distribution Bar. 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. C. As per clause 26. 8. 2. It is appropriate to design the slab per unit width, hence b = 1000mm. 7. Distribution bars are 8 mm in diameter @ 150 mm centre to centre spacing. 10mm Ø hor. The length of a distribution bar in east side is, = (17′-1½″) + 2 × 10″ = 18. And, in compression zone, same as in (a) above. , addi-tional bonded shrinkage and temperature reinforcement conforming to 7. Cutting Length: = total length — 2 x clear cover = 4000 - 2 x 20 = 3960 mm or 3. Total length = 3. f ck = 25 Mpa. 2 m), regardless of steel grade. What should be the diameter of chair bars used in construction? Typically, chair bars are made of reinforcement with a diameter of 12 mm and above. 3. In general, the main bars are usually placed parallel to the shorter dimension of the slab to reduce the slab's overall span length and provide. In the. Total Cutting Length Of Rod = 2nos x 1. How do you calculate slab distribution bar? Formula = (total length – clear cover)/center to center spacing + 1 main bar, = (5000 – (25+25))/100 + 1, = 4950 divided by 100 + 1, = 51 bars. 12. How to Design Concrete Structures to Eurocode 2 - Chapter 2: Getting started. Workmanship and jobsite conditions. 8. Note * Spacing rationalised to suit punching shear links. Minimum number of bars for a square column are 4 and for circular column are 6. 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. Now. dia.