3(d) and 17. Area of reinforcement per metre width of spacing. 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;. total angular change of tendon profile from tendon jacking end to point under considerations, radians. Clear cover (top & bottom) = 50 mm. 5h ≤ 450mm (in areas of concentrated loads 3h ≤ 400mm) Where h is the thickness of. 1—General 8. Concrete cover to main reinforcing bars shall be provided per AASHTO Table 5. Now. 9 Factored loads Factored dead load = 3. Cutting length= 9000 – 2 x 50 =8900 mm =8. , 1-hr. The primary reinforcing bar is placed perpendicular to the bigger side or parallel to the shorter direction to give suitable support. Step 3 – Top Distribution. Step 2: Calculate cutting length of main bars and distribution bars. 11. Distribution Bar. 2 – Spacing of tendons shall not exceed 6 feet. 0014: (a) Slabs where Grade 40 or 50 deformed bars are used: 0. FIrst, find number of rods required for main reinforcement and distribution. 5. 5 M from the edge of wall and at both ends 6 mm plain M. and the clear spacing between the bottom bars a = 60 mm. reinforcing parallel to load per inch of slab width perpendicular to load / slab thickness) (steel yield stress)) f. According to ACI Code. 3, 1) The horizontal distance between parallel main reinforcement bars shall not be more than. Before calculating the cutting length, we need to calculate each part length of chair bar. 2, or >0. 3. 7. The code requires this value to be the minimum of these three values. 1 or the bottom bars required by 8. April 2, 2023 May 25,. 785 x d^2 = 0. 3. Also useful for attaching stirrup bar effectively. Number of Main Bars = Ly / spacing + 1 = (4000/150) + 1 = 27 nos. 1 Definitions 25. 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. C. Roof drainage system (Adapted from the International Code Council). length of. Other notations, wherever used, areQuick guide to design of one way slab – with IS Code 456:2000. (i) The pitch of the main tensile bars in R. As discussed earlier, assume that the beam is reinforced with two layers of #11 reinforcement and clear spacing between layers = 1 in. Ld = Development length of the bar. 21. 7. Type and spacing of the control and construction joints. Slabs - - - maximum spacing is 3*deff or 300mm whichever less side ) of the deformed bar ( see Note ) NOTE - In accordance with IS : 1139-1966. c) Slab reinforcement percentage less than 0. Here, ∅ is the bar diameter. d = Effective depth. The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. The term "standard hook" as used in this Code shall mean one of the following: (a) 180o. bar due to its non-availability. 3%. 14 x 5 x 5 = 78. A diagonal crack that might result in shear failure, as suggested in Fig. Distribution bars are placed on the top of the. For interior Spans: According to the code, the moments can be distributed according to factores shown in the figure: II. 6. 2. 12% of high yield strength deformed bars. 2 shall be provided between the ten-dons at slab edges extending from the slab edge for a dis-tance equal to the tendon spacing. . 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 ). For. Temperature distribution due to heat of hydration and internal stresses caused by outside cooling in a free standing concrete block. slab, shall not. 7 For temperature steel only, maximum spacing shall not exceed five times the slab thickness h nor 450. 7. 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) For main bars, maximum spacing is restricted to 3 times effective depth or 300. 3: Two-way slabs supported on four sides; Clause 6. 12% gross c/s of slab – for HYSD bars; Spacing of distribution bars. The spacing shall be less than five times the slab’s adequate depth, or 450 mm in the distribution bars. Development length =40d . Design the slab using the data given below; Purpose of building – Residential. 2. 2. 5. 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. Number of Main Bars = (Length of Longer Side / Spacing) + 1 = (6000/150)+1. 960m. Proportioning of flat slabs: As per cl. Reinforcement details bay C-D, 1-2. three times the effective depth of solid slab or; 300 mm; whichever is smaller. As per ACI Code, In slab, minimum reinforcement shall be 0. 7. For a 6 in. Important Point: As per IS 456:2000, the limit on minimum reinforcement along either direction has been specified. 225m. 4. NOTE 3 - In co1 3. 6 𝑀𝑃𝑎. Distribution Reinforcement for Stairs. 1. 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. e. Exceptions: 1. Actual variety of 1 sides rebar =Number of main bar – rebar of the middle. 6H to 0. Step 1. 4—Construction load distribution 3. Additionally, the clear space between the transverse bars and lapped bars may not exceed 1. 12: Reinforcement detail in continuous slab 3. 5, the lateral spacing of the flexural bars should not exceed three times the thickness of 18 inches. 2 and 9. 2. 1. As per ACI Code, In slab, minimum reinforcement shall be 0. 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. 5 times the diameter of the longitudinal barR4405. 960 x 16 =. 4. 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. If a closer spacing of bars is required at the columns, as per Section 13. The spacing < 300mm and <3*d as per Cl. Tech. 0020. M o can be distributed, according to factors given in the table 8. , and dowel length to be 18 in. Depth of footing = 750 mm. 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. The reinforcing bars must extend into the slab beyond the critical section for a required length. is lapped with a lower bar of 20mm dia. t + DChair bars are used primarily on the slab and flooring. Important Points. to carry a uniform live load of 7500 Pa. Distribution Bar. 5φVc except for the following cases: A. Calculation for distribution bar: Bending moment for distribution. 2 For one-way shallow foundations, two-way isolated footings, or two-way combined. 6. Minimum Reinforcement Ratio in Slabs. 6. bars at every 3 layers of chb finished surface wall intersection b h lintel beam reinf. Design size and spacing of dowel bars at an expansion joint of concrete pavement of thickness 20 cm. 6—Factors affecting the construction load distribution 3. 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. Spacing of bar = area of a bar * width of strip / area of reinforcement required = 78. One Way Slab Bar Bending Schedule Calculation. 25 x 87 =34. Every alternate bar is cranked up to 0. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. 3. Maximum size of bars in slabs As per clause 26. cm. 2 of ACI 318-11, it should be clearly denoted on the structural drawings. is more that the diameters used here. Width of the Slab = 2 m = 2000 mm. Distribution bars typically have lesser dimension bars compared to main bars. Spacing should not exceed smaller these two values. 3. Fig. 318-19 Sections 7. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. Bars shall not be smaller than No. 4. 3% (100As/bd < 0. 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. Number of Required Bars Formula = (Length of slab / spacing) + 1. Design the slab using the data given below; Purpose of building – Residential. a) Slab depth does not exceed 250mm when the steel grade is 250. For longitudinal bars in slabs. 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. 3. Provided spacings, therefore, satisfy the requirements. the square of the thicker slab when f=0. 2. No. 5. 6H to 0. iv) Detrmine Sapcing of bars at critical section based on designed value of Ast by selecting appropriate bar dia. A cantilever slab 200 mm thick is 1. Inclined length = 0. Reinforcement chairs should be made with a minimum of 12 mm bar. 3. Minimum spacing for distribution bars is, (1) 5d = 5 X 76 = 380 mm (2) 450 mm . 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. If shear reinforcement is required for in-plane strength, s shall not exceed the smallest of 3h, 18 in. Near lapped joints, if the diameter of the longitudinal bar is greater than 14 mm. What is the maximum spacing of a distribution reinforcement to be used in a one way slab as per IS 456? b. 75 Nos. 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. f d n §· ¨¸ ¨¸ ©¹ ©¹ Since the required nominal moment from Section 1 (M n,reqThe Chinese code “Code for composite slabs design and construction” (CECS273:2010) states [34] that steel-bars truss can work with concrete as upper and lower bearing reinforcement in concrete, but without considering the role of steel-bars truss as a whole and bottom PSS, the bearing capacity of SBTS is calculated according to ordinary. 3. 1 for minimum thickness of non-prestressed two-way slabs without interior beams is revised to include Grade 550. The maximum spacing between stirrups is smallest of the following provided that (V s <0. 8 of BS EN 1992-1-2 Eurocode 2: Design of concrete structures – Part 1-2: General rules – Structural fire design provides data which can be used to determine the thickness and cover requirement for concrete elements. Conclusion. 1. Spacing Requirements. 096 square inches per foot (or #4 bars at 18 inches center to center to meet ACI criteria, As = 0. 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. If shear reinforcement is required for in-plane strength, spacing of longitudinal reinforcement shall not exceed l w /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. 9, page 341. . The spacing of distribution bar should not be greater than 5 times the effective thickness of slab or 450mm whichever is smaller. Effective depth=d provided =120-20-4= 96 mm. BS EN 1992–1–1 section 6. The below specified 7 steps are generally used to design the two way slab. 6. 7. That is 11′. 26. 97 kN/m 2. slabs, walls, and joists - #14 and #18 bars - ½ inch; Slabs, walls, and joists - #11 bars and smaller - ¾ inch ; Beams and columns. Tayabji (1986) identified the following categories of dowelmillimetres and N represents the identification number of the bar/bars given consecutively. 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. If the maximum diameter for. for exterior walls or 30 in. BS EN 1992–1–1 section 7. For distribution bars (cl. 8. 1) The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. however with a maximum spacing of 4. 5. 8 say 16 nos. (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. e. Modify ACI 318 Sections 17. In this kind of. 4. 26. Slab steel grid not less than Fe500. 1 or the bottom bars required by 8. Diameter of Distribution Reinforcement Bars = d d =12mm. Maximum spacing between Individual Bars: The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. As per IS 456: 2000, Cl. Number of Main Bars = Ly / spacing + 1 = (4000/150) + 1 = 27 nos. A s,min,reqd ≥ b*h*0. The diameter of the chair bar should not be less than 12 mm. 3. The diameter of main bars may be from 8 mm to 14 mm. 7. 347. 1. As = 0. 1. Number of Distribution Bars = Lx / spacing + 1 = 3000/150 + 1 = 21 nos. 3. The distribution bars provide the following functions in slab construction: 1. Distribution bars of diameter 12 mm and center to center spacing 150 mmm. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. 2. slab should not exceed three times the effective depth of the slab or 450 mm whichever is smaller. 896 x Total Length (where d is in # Nos. Slab Thickness = 150 mm. 2 Symbols Relating to Shape of the Bar Along Its Length As per IS 456: 2000, Cl. 4. of chair bars = Area of structural reinforcement in sqm / chair bar per sqm. According to Clauses 8. 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. The maximum diameter of the reinforcing bar in a slab should not exceed 1/8th of the total thickness of the slab. 2 or 8. 3. shall be the lesser of (i) five times the effective depth, or (ii) 450 mm. 4 Deck Overhangs for guidance on deck slab bars. member has shallow depth of less than 150 mm (ex. stationary live loads less than 400 po unds per square foot. however we need to understand the requirement of chair. Distribution Bar = 12 Number of The Distribution Bar. , addi-tional bonded shrinkage and temperature reinforcement conforming to 7. 7. 2 MineralAdmixtures 5. According to ACI Code 7. The ACI 318-19 provides a number of requirements regarding slab thickness, concrete cover, and reinforcement ratio which facilitate the design process. A distribution bar is equal to (total slab length- 2x clear cover length)/center to center spacing of the bars + 1. DESIGN OF SLAB: Design of typical Floor Slab: We have thickness of slab as 130 mm. 6 For two‐way slabs, maximum spacing of bars shall not exceed two times the slab thickness h nor 450 mm. 1. 2. 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. #IScodes #Concrete #Concretetechnology Recent & Related Videos Concrete. C. #IS456Explanation#SpacingofReinforcement#IESGATEWizIn this Video Part-45,detailed discussion of IS 456-2000 provisions of Spacing of Reinforcement Bars ha. , addi-tional bonded shrinkage and temperature reinforcement conforming to 7. 3 Slenderness Limits for Columns 25. Total wt of Bars = 150. 3. 2. e. 2R-8 4. 2). 3. 1-3). For 8 mm diameter bar 7 inches to 9 inches center to center c/c. Placed at a shorter span. However, it is not a code, so many engineers do use portions of ACI 318 on their projects. No of bars = 41 nos. LL = 6. But even after that If d,provided < d,reqd, slab thickness is to be increased and check for deflection is to be satisfied. 50 8. Considering M20 grade of concrete and Fe 500 steel of diameter of 10 mm. (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. Spacing of Main reinforcement bars = s m = 150mm c/c. 1. 3. However,. Thickness of Slab = 0. 6666666667 = 21 nos No of bars = 21nos . What Is Bar Bending Schedule | Preparation as Per Bs 4466 | Tolerances as Per Bs 4466; Disadvantages of Dowel Bar. Note: The minimum clear spacing of bars is not kept less than 75 mm (Preferably 100 mm) though code do not recommend any value. Opposite length of bar = 2950. 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. In RC slabs and PT one-way slabs, the clear distance between bars is limited to the smaller of. About this chapter: Chapter 3 covers general regulations for plumbing installations. 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. 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. Concrete Reinforcement January 2008 15-3. As per clause 26. 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. 7. slab known as a joist system can be constructed without any shear reinforcement in the joist ribs. Maximum Spacing between Stirrups . 25 kN/m 2. 3. ACI 360R, Section 6. 2 m), regardless of steel grade. 7. 1 for minimum thickness of non-prestressed two-way slabs without interior beams is revised to include Grade 550. 3. 6 in the following cases; In sections within a distance equal to 4 × thickness of wall above or below a beam or slab. For Min Steel: 3d ——— Where. Distribution Bar = width of the foundation – 2 CC ÷ Spacing +1. slab should not exceed three times the effective depth of the slab or 450 mm whichever is smaller. This type of reinforcement is convenient for modeling beam reinforcement. 5% or 0. 4. Area of Steel 'Ast req. 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. Check for Cracking. 2 of IS 456) shall not exceed 140/8 = 17 mm is also satisfied with the bar diameters selected here. 3. The distribution bars should be (2000- 2 x 25) /125 + 1. 5% steel (continually reinforced) as described in Section 8. 133 square inches per foot). , 0. 4 and shall have a total area of not less than 0. Spacing of chairs should be per 1 m or 1 no. Bar cranking is the process of bending up the bottom steel bars in upward direction. Reading time: 2 minutes. 12% of the gross cross-sectional area if HYSD bars (Fe 415) are used. 12. Main Reinforcement bars are placed in shorter direction and Distribution bars placed in longer span direction. For distribution bars the maximum spacing is specified as 5 times the effective depth or 450 mm. 15%of gross cross-sectional area if plain bars are used and 0. Cranking is also used in two way slabs. 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. 460/2=1. 2. 8. Spacing of bar = area of a bar * width of strip / area of reinforcement required = 78. EXAMPLE PROBLEM 1. Given, Length of longer span = 5000 mm. dia. HYSD bars for upto M45 grade concrete and 0. 3. Total Length of Distribution Bars = 786. 2: Alternate method for showing two-way slab reinforcement reinforcing bars should be clearly scheduled on the drawings. 1.