The Main. 1 or the bottom bars required by 8. One Way Slab Bar Bending Schedule Calculation. The minimum cover for cast-in-place concrete is specified by the ACI 318 Building Code. Ex. 25 kN/m 2. 12, apply only to one-way slabs (all code sections cited hereinafter are from ACI 318-08): “7. Two way slabs Since our typical floor slab is symmetric in two directions, we analyze only a representative section for moments and their adjustments, as shown below. BS EN 1992–1–1 section 6. 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. 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. 08 times the gross area of the column. B. 1. 3 For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall ‘be rounded off in accord-Table 5. But even after that If d,provided < d,reqd, slab thickness is to be increased and check for deflection is to be satisfied. 1. (ii) The pitch of the bars provided to act as distribution bars or bars provided to guard against temperature and shrinkage in an R. Bar Spacing. f yk = 460 Mpa. 34 kg ——– (1) Section 1 Total = 33. For longitudinal reinforcement in columns of size 200 mm and less, with 12 mm diameter bars as longitudinal steel. 5 mm 2. 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. The. For a 6 in. Bar cranking is the process of bending up the bottom steel bars in upward direction. 4 and shall have a total area of not less than 0. • Maximum area of main steel in slab = 4% 𝑜𝑓 𝑏𝐷 (As per ACI). M o can be distributed, according to factors given in the table 8. 2 mm. Maximum spacing of bars for slabs • Main bars: 3h ≤ 400mm (in areas of concentrated loads 2h ≤ 250mm) • Secondary bars: 3. however with a maximum spacing of 4. 10mm Ø hor. Provided at the bottom of the slab. Given, Length of longer span = 5000 mm. Type and spacing of the control and construction joints. 04𝑥1000 𝑆= = = 272. Given data: Distribution bar dia. As per ACI Code, In slab, minimum reinforcement shall be 0. Generally, a #4 (1/2″) diameter reinforcing bar with a minimum grade of 40 is used for standard residential slabs. The distribution bars’ primary function is evenly distributing the load across the slab. (14) Step Find the load transfer capacities , , and of single dowel bar with the. length of dowel bar and a maximum joint opening of 0. the total length of the leg is 2×spacing +50. 15 mm or diameter of bar. 2, or >0. rahuledu said: as per IS 456:2000, chair shall be fixed 1 no in 1 Sq. Section 8. The slab is not. Spacing =80mm. 4. 8. 5. 1 Conditions of test specimens 32ACPA Guide Specification | Dowel Bars for Concrete Street and Highway Pavement | ACPA M254-21a August 1, 2021 | Page 4 of 12 2. 3. Note: The minimum clear spacing of bars is not kept less than 75 mm (Preferably 100 mm) though code do not recommend any. , 450 mm. 2. The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. Refer to "Determination of Bonded vs. Particular care isIRC SP 066 : 2016 is a standard specification and code of practice for the design of steel pedestrian and cycle bridges in India. 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. 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. 3. Workmanship and jobsite conditions. Step 1. Distributed reinforcement is a bar spacing applied over a polygon area. 2. 26. 3. 5. 4 Spacing Between Longitudinal Bars. thick slab will increase the potential for random or out-of. Nos of Bars =. 8. e. Minimum Reinforcement Ratio in Uniform Footing. Spacing between bars = 0. Grade of concrete ƒck, Grade of Steel ƒy, Concrete cover, Clear long spam, Clear short spam, With of supporting beam, Live load, Floor finish load, The diameter of the main and distribution bar, and; Assume the. 2 d t kips in. 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. Now. 9. 1 or the bottom bars required by 8. TRANS REINF - Reinforcement required along the transverse direction ( along local Y axis of the plates ). 3 Slabs-on-ground with turned-down footings. 2) b = edge distane of bar for calculation of lap length (cl. 26. of Main bars = (3000)/150 + 1. 3 Slabs-on-ground with turned-down footings. As per IS 456: 2000, clause 26. Now, we will calculate the length of the three parts of the chair bar separately. 3. C. #IS456Explanation#SpacingofReinforcement#IESGATEWizIn this Video Part-45,detailed discussion of IS 456-2000 provisions of Spacing of Reinforcement Bars ha. 3—Corner restraint in slabsColumn = Self Weight x Number of floors. 12% of the total cross sectional area , when HYSD bars Fe415 are used. 0104 Ai. , 300 mm. Spacing should not exceed smaller these two values. Size of the bar is less than the main bar. Minimum S&T reinforcement quantities required by ACI 350-01 and11. But even after that If d,provided < d,reqd, slab thickness is to be increased and check for deflection is to be satisfied. 9 m = 3. 2 Maximum Distance between Bars in Tension. 2. 2. Spacing of main reinforcement bars = 1000/ [A st,req / Area of single bar] = 1000/[660 / 78. C. Distribution Bar. 6. Placed at a shorter span. For distribution bars the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is less. 75 m. Spacing of bars = 180 mm c/c < 300 mm and 3d ok Distribution steel =. If dowel placement deviates from the desired position, it is said to be misaligned. 2. 5tf or 0. For example, for 12mm. 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). 1. Longitudinal reinforcement should not be less than 0. 3 – When spacing of tendons exceeds 54 in. k’ = 0. . This spacing should be reduced by a factor of 0. For longitudinal reinforcement in beams. 2 SlabsContinuous OverSupports 24. 5 bar or two No. Load Distribution. 2: Alternate method for showing two-way slab reinforcement reinforcing bars should be clearly scheduled on the drawings. The number of the bars is seventh factor taken in basic rules in column design. 6. 25 8 #5 12 6 6 2 4. dia. 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. 890m. 2 of ACI 318-11, it should be clearly denoted on the structural drawings. 2 m), regardless of steel grade. 9. 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. This spacing should be reduced by a factor of 0. Tech degree in Civil Engineering with six specializations, i. 3. 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 reinforcing bars must extend into the slab beyond the critical section for a required length. slab along the shorter span, 3mm per meter span. 002 times the gross cross-sectional area of the footing. The “D” bars shown in the tables conform to Article 9. Use #4 bars at 25-inch spacings center to center each way, As = 0. 26. 1 General 24. 15%of gross cross-sectional area if plain bars are used and 0. Total No’s of Distribution Bars = (Total layers of Dist Bars in Walls are 4) = 10 x 4 = 40 No’s Total Length of Distribution Bars = Cut Length x No’s of Bars. 10. Figure 3:. 318-19 Sections 7. According to ACI Code 7. 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. 1-3). Ex. 3. thick slab, the maximum joint spacing should be limited to 12 to 15 ft. 1. 26. Distribution bars are provided perpendicularly with the top of the main bar. 12% of the overall sectional area. 15% of the total cross-sectional area of the slab (bD). The maximum clear spacing between parallel bars shall not be more than 1 N-6O. Spacing: ACI Code 7. 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. About this chapter: Chapter 3 covers general regulations for plumbing installations. 5. Number of Main Bars = Ly / spacing + 1 = (4000/150) + 1 = 27 nos. The Distribution bars will be 8 mm in diameter @125mm c/c spacing. It covers the general features of design, loads and load combinations, structural analysis, materials, fabrication, erection and maintenance. The no. Weight of Distribution Bar for Waist Slab. steel bars. 5% or 0. t + DChair bars are used primarily on the slab and flooring. The maximum spacing of reinforcement in slabs is 3d or 300mm(minimum of both). Distribution Bar. 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. Spacing =150mm. Every alternate bar is cranked up to 0. Diameter of top and bottom distribution bars = 16 mm. 3(d) and 17. The main conclusions can be summarized as follows: • The proposed method gives a good estimate for crack. e. 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. 31kg says 35kg. 285+150. 53 Compute moments At support: ( - ) M1 = 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. = 16 mm, spacing @ 150 c/c. 40 cm;. ( IS: 456-2000 ). Spacing = 150mm c/c as per given details = (2950/150) + 1 = 20. Radius =length /2. 12. Total Cutting Length Of Rod = 2nos x 1. 3. No of Bars/m 2 = Factored Load / Pcr. = 175 mm Last perimeter, from column face, min. 16. 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. 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. 6% of the gross wall area for Grade 60 or Grade 40 bars, respectively. The size and spacing of S1 and S2 bars shall be determined by design. ,). 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. 3, 1) The horizontal distance between parallel main reinforcement bars shall not be more than. 4 bar at the top and the bottom of the footing or one No. From a study that compared voided slabs and solid slabs, researchers observed that for typical bays of 7. Given, Cranked bars or Main bar of diameter 16 mm and center to center spacing 150 mm. 9 for flat slabs with drops. Such splices, where used, shall be welded, lapped or otherwise fully. e. The maximum spacing of minimum steel (distribution bars) is the lesser of 5(135) and 450 mm. 3d or 300 mm whichever is smaller for main steel. 3 Aggregates 5. 9. No. 14 x 5 x 5 = 78. 8 ACI 318 , Section 17. Given the radius of relative stiffness of 90 cm. 133 square inches per foot). , B. 5d or 450 mm whichever is smaller for distribution steel. 75 Nos. 2 mm. 3. 6H to 0. 1 Spread Box BeamsA. For distribution bars (cl. Slab steel grid not less than Fe500. 3. 5 m as per IRC. 6. Main Reinforcement Bars are used to transfer the bending moment developed at the bottom of the slab. 25 in. 1 or the bottom bars required by 8. 1. The distribution bars provide the following functions in slab construction: 1. What is the maximum spacing of bars in a flat slab? The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. 2, The diameter of reinforcing bars shall not exceed one-eighth of the total thickness of the slab. Head ( E ): The length of the head = [(2nos. 0018. Most of these formulas are based on the analysis of results of tested beams or oneway slabs. 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. Estimation of the joint movement, is therefore, theTwo-Way Slabs 6 b- Distribution of the total factored static moment to negative and positive moments: I. = 2sqm/1sqm = 2nos. 6. As per IS 456:2000, in rcc slab, maximum diameter of main bar and distribution bar should not exceed 1/8th thickness of slab. , 300 mm. To find the Bar Bending Schedule for Slab we use the following formula, No. 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. Fig. 1% steel allows sawed contraction. Note that required A s must be furnished in each direction. 7. Sawcut Joints A typical SOG includes three different types of joints, described in detail in ACI 360R Chapter 5. Design the slab using the data given below; Purpose of building – Residential. Cutting length of main bar = Clear span of slab + (2 x development length) + Inclined length – (Bend length) Clear span of slab = 2000 mmFor one way slab, distribution bars are required to tighten the main bars together – since it has only one spanning reinforcement. Sub-slab details (i. 785 x 16^2 = 200. 2) For main bars, maximum spacing is restricted to 3 times effective depth or 300 mm whichever is smaller. 3. 1. how to calculate the number of rebar in an exceedingly circular block. Number of Required Bars Formula = (Length of slab / spacing) + 1. The diameter of the chair bar should not be less than 12 mm. 5 bar is permitted to be located at either the top of the slab or bottom of the footing. 12. Select the correct answer using the codes given below: A. d = Effective depth. 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. What is the maximum spacing of a distribution reinforcement to be used in a one way slab as per IS 456? b. t 12mm stirrups at 150mm ctrs Two terminated bars A A Elevation Section A-A Lsy. Length of distribution bars = 6. with a banded tendon distribution is achieved without this. 1 Cement 5. Slab steel bar not less than 10mm dia. 12: Reinforcement detail in continuous slab 3. MOM-X – Longitudinal moment, corresponding to which LONG. Provided to resist the bending stress. Calculation of ratio of the length of long span to length of short span. 21Two-Way Slabs 6 b- Distribution of the total factored static moment to negative and positive moments: I. 1—Early-age concrete material strength development 4. Reading time: 2 minutes. Concrete cover = 25 mm. 3. Lap length diameter: When we extend the top bar of the column from the bottom bar, having an unequal diameter, then the lap length is calculated for the smaller dia. Transverse joint spacing should not exceed 125% to 150% of the longitudinal joint spacing. 1. Ensure a minimum number of bars in a square column is 4 and in a circular column, 6. Breadth of Footing = Y = 1. 1. The Clear cover will be 25 mm (Top or Bottom) and the thickness of the slab will be 150 mm. Only 2. Collectors, Chords and ConnectionsIS Code. Distribution bars of diameter 12 mm and center to center spacing 150 mmm. for exterior walls or 30 in. = 16mm, spacing @ 150 c/c. 1 (2) states that, distribution should minimum 20% of the main reinforcement. Length of waist slab= L. 133 square inches per foot). Side clear cover of slab 25 mm; Thickness of slab is. 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. 5 M from the edge of wall and at both ends 6 mm plain M. Thus, there are three relevant issues: 1) According to ACI 318-19 Section 7. Given the radius of relative stiffness of 90 cm. 1. Heavy loads. Check for Cracking. 7. Bar Spacing. 230m. general building code. 3. M. It is also important to keep slabs as square as possible. Minimum spacing for distribution bars is, (1) 5d = 5 X 76 = 380 mm (2) 450 mm . 96 x 1000 / 1536 = 130. bars in two-way slabs. No of bars = 41 nos. In ACI 350R-89, the recommended minimum S&T reinforcement for walls with movement joint spacing greater than 60 ft (18. Opposite length of bar = 2950. 3) or the distance of centre of gravity of the concentrated load from the nearer support (ci. 3 m) is either 0. 5d = 5 * 130 = 650 mm. 12. of Main bars = (Width of Slab/Spacing) + 1. The maximum spacing should be reduced by a factor of 0. 1 Purchaser’s tests of steel reinforcing bars 28 Section 6 Methods of testing 32 6. The equivalent of closer-spaced, typical slab bars can be achievedf DESIGN of ONE-WAY SLAB based on NSCP 2015 and ACI 318-14. 1 of IS 456), the maximum spacing is the lesser of 3d and 300 mm i. 3. The Department of Civil Engineering at IIT Kanpur is producing since 1961, high quality technical manpower needed by industry, R&D organizations, and academic institutions. 6. spacing of bars should not be more than. 3) or the breadth ofthe rectangular beam or slab or the breadth of the rib in case of flanged beam (ci. 12% of the gross cross-sectional area if HYSD bars (Fe 415) are used. 2—Construction load factorsThe diameter of the main bar should not be less than 8mm for the HYSD bar and 10mm for plain bars. Provided at the bottom of the slab. The distribution bars should not be under 8 mm in a diameter or not be over 1/8 of the thickness of the R. the quality and basic shape of reinforcement bar shall be specified. Main Bar. 2. from deviations in bar spacing and bar size are shown in figure 5. IS 456: 2000 CONTENTS PAGE SECTION 1 GENERAL J SCOPE 2 REFERBNCES 3 TERMINOLOGY 4 SVMBOU SECTION 2 MATERIALS, WORKMANSHIP, INSPECTION ANDTESTING 5 MATERIALS 5. 4 Slabs Spanning in Two Directions at RightAngles 24. Basic considerations. bar per intersection 10mm Ø vert. 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. M o can be distributed, according to factors given in the table 8. Always main bar use in shorter span. 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. 3. Step Assume load capacity of dowel bar is 40 percent wheel load, find the load capacity factor f as. Total Length of Distribution Bars = 786. 5% steel (continually reinforced) as described in Section 8. , and ℓw/3. 4. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. 11in2) Spacing = As 0. Calculated area; 5 x d; 450mm; Diameter of 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. 3. 8. Conclusion. 002 times the gross cross-sectional area of the footing. Main Steel Bars. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. 12 x 100cm x D cm=0. Step 2: Calculate cutting length of main bars and distribution bars. For distribution bars the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is less. The maximum reinforcement ratio for columns is 0. BS EN 1992-1-1 Annex 1 1. 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. cm. The slab is. , addi-tional bonded shrinkage and temperature reinforcement conforming to 7. The slab is not. 2. 3 of IS 456). 1) The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. 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. 75 m. slab should not exceed three times the effective depth of the slab or 450 mm whichever is smaller. 305. For 8 mm diameter bar 7 inches to 9 inches center to center c/c. Lits-II 1.