Placed at a longer. Top and bottom clear cover of slab is 20 mm. To calculate: Spacing of replaced 12mm. An interaction between steel requirements for bending in the slab and longitudinal shear has to be considered. from deviations in bar spacing and bar size are shown in figure 5. 15% for Mild steel bars. 7. Conclusion. This portion is coming at the top of the bottom main bar. What are the different functions of distribution bars in concrete . Weight of Distribution Bar=64/162. Loads which consist of any on e of the following: moving live loads exceeding a. Spacing of 10mm bar = S1 =150 c/c. 2. Bar cranking is the process of bending up the bottom steel bars in upward direction. If shear reinforcement is required for in-plane strength, spacing of longitudinal reinforcement shall not exceed l w /3. The maximum clear spacing between parallel bars shall not be more than 1 N-6O. 2 or 8. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. Now. bending dimensions shall be measured as shown for appropriate standard shapes. Calculation for distribution bar: Bending moment for distribution. The dowel bars are provided in the direction of. 2 As per NSCP 2015, a minimum shear reinforcement in concrete design shall be provided in all regions where Vu > 0. =Eq. 2. = 27. 2. 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. Step Assume load capacity of dowel bar is 40 percent wheel load, find the load capacity factor f as. The diameter of the chair bar should not be less than 12 mm. of bars = { (L or w – concrete cover for both sides) ÷ spacing} +1 Equation 8. It is mainly to prevent upward bending moment near the joint. 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. Earth Pressure intensity (q) = N/A prov = (18765. 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. Minimum number of reinforcing bars. 1 of IS 456), the maximum spacing is the lesser of 3d and 300 mm i. What is the maximum spacing of a distribution reinforcement to be used in a one way slab as per IS 456? b. Spacing of Main Reinforcement: The maximum spacing of bars shall not exceed. Basically slab is the horizontal member which is rests on the beam section. The length of a distribution bar in east side is, = (17′-1½″) + 2 × 10″ = 18. BS EN 1992–1–1 section 7. Note * rationalise centre of bars in column strips T2 and B2 to 175 mm centres to suit punching shear links. 5] = 120 mm c/c. 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. 3. 13. , B. Figure 3. 25 x 87 =34. 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. Main Reinforcement Bars are used to transfer the bending moment developed at the bottom of the slab. The previous code that allowed up to Grade 520 was changed to Grade 550, and related regulations were modified. normally lower dia rebar tends to more sagging while placing in top layer. 6. 7. In both cases, the minimum bar areas are equal to 0. TWO WAY SLAB DESIGN SPREADSHEET:Fig 10: Reinforcement of a slab. 2. 4. 21. Collectors, Chords and ConnectionsIS Code. 2 – Spacing of tendons shall not exceed 6 feet. Head ( E ): The length of the head = [(2nos. 19 or greater, the minimum concrete cover is 5 cm. Design of slab. For eg. This is needed both to prevent splitting of the con-crete adjacent to the stud and to allow load to spread out across the width of the slab. As per IS 456: 2000, Cl. , 450 mm. 5. The term "standard hook" as used in this Code shall mean one of the following: (a) 180o. The maximum spacing of bars shall not exceed. e. Number of Main Bar & Distribution Bar: First, we have to calculate the number of bar required for the slabs. 7. Number of Main Bars = (Length of Longer Side / Spacing) + 1 =. The length of a distribution bar in west side is the same as the east side. 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. Distribution bars are placed on the top of the. 2 Maximum Distance between Bars in Tension. 60 kN/m. Bar schedule for Slab; Table 3 : Bar schedule for SlabArea of single bar = (3. 3: Two-way slabs supported on four sides; Clause 6. The distribution bars are arranged to retain the mesh in perfect place and sustain the center to center c/c, bars. The span requirement for the slabs is given by ACI Code 8. ”Distribution bars are typically used in conjunction with main bars, and they are often spaced at regular intervals along the length of the main bar. where. 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;. slab known as a joist system can be constructed without any shear reinforcement in the joist ribs. Thickness of Slab = 0. Cutting Length: = total length — 2 x clear cover = 4000 - 2 x 20 = 3960 mm or 3. Larger areas, lower loads, and higher seismic zones. Type and spacing of the control and construction joints. Consider the ACI 318-14 code according to which the Ø is the strength reduction factor as specified in table 21. The diameter of main bars may be from 8 mm to 14 mm. 318-19 Sections 7. 5 mm 2. = 175 mm Last perimeter, from column face, min. Distribution Bar. The following minimum limitations relating to various structural components shall be followed: Thickness of top flange : 100 mm. 5. 2. 8. f. The main reinforcement of an RC slab consists of 10 mm bars at 10 cm spacing. Basic considerations. C. 85MPa) was added as a code requirement. 5 M from the edge of wall and at both ends 6 mm plain M. Considering M20 grade of concrete and Fe 500 steel of diameter of 10 mm. 3. stationary live loads less than 400 po unds per square foot. The minimum and maximum spacing reinforcement in concrete structural members such as beams and slabs. 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. W = 3. 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. 18/100× × 100× D = 0. Exceeding a joint spacing of 15 ft. 26. 7. Number of bar = total width /spacing +1. however with a maximum spacing of 4. 10 the minimum bar spacing for bundled bars shall be calculated based on the derived diameter instead of calculating from individual. 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. 2R-8 4. Check for Cracking. 08 times the gross area of the column. 24. Dia of Distribution Bar=16mm. Note: The minimum clear spacing of bars is not kept less than 75 mm (Preferably 100 mm) though code do not recommend any value. Cover block use 15 to 20mm. The primary reinforcing bar is placed perpendicular to the bigger side or parallel to the shorter direction to give suitable support. Total length of bar required for distribution bars of Floor Slab 1 = 131m. bars at 400 mm o. 890m. The use of #4 or #5 bars is at the discretion of the Structural Project Manager if both available diameters meet demand. If the maximum diameter for slab thickness is 75 mm, so the diameter of reinforcing bars should be 8 mm. Minimum spacing for distribution bars is, (1) 5d = 5 X 76 = 380 mm (2) 450 mm . 5 m. 6. 5 h Finding out bar spacing: Let us chose # 3 bar (0. 4 Deck Overhangs for guidance on deck slab bars. Spacing of bar supports depends upon the size of the reinforcing bar being. vapor retarders - some times referred to as vapor barriers, insulation, etc. bar. Effective Depth: (130-15-10/2) = 110 mm. Heavy loads. Two way slab building. LL = 6. 26. Design size and spacing of dowel bars at an expansion joint of concrete pavement of thickness 20 cm. Radius = 2. 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. For distribution bars the maximum spacing is specified as 5 times the effective depth or. This is plotted against the overall fire rating of the structure that is being designed. Minimum Bar SpacingAs per AASHTO LRFD, section 5. What Is The Maximum Bar Spacing In Reinforced Beams According To IS 456? Normally this. 4. If a closer spacing of bars is required at the columns, as per Section 13. of Main bars = (Width of Slab/Spacing) + 1. 4. 2. Sub-slab details (i. Total Length of Distribution Bars = 19. 6. 12% of the overall sectional area. 4 MoVEMEntS And rotAtIonS: 4. 2—Minimum flexural reinforcement in prestressed slabs 8. 4 bars in the middle third of the footing depth. slabs, walls, and joists - #14 and #18 bars - ½ inch; Slabs, walls, and joists - #11 bars and smaller - ¾ inch ; Beams and columns. For distribution bars the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is less. No of bars = (opp length/spacing) + 1. 15=7no’s. 2. Provide main reinforcement of 10 mm diameter bars at 120 mm c/c. Transverse joint spacing should not exceed 125% to 150% of the longitudinal joint spacing. The design method is followed as per Annexure D of IS 456:2000. Provide a thickness of D=120 mm. 2, can form no closer to the facesee table 3 for spacing. Main Steel – 3d or 300 mm whichever is smaller; Distribution Reinforcement for Concrete Slab Design: The area of distribution reinforcement shall not be less than 0. Here, ∅ is the bar diameter. 25*3. According to Clauses 8. 2(5)In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. 1-3). 715m long, and it is supporting a blockwork load at 1. 4. Special surface finishes, including coatings. 00mm Bottom Footing Clear Cover (F, CL). 4 Minimum Eccentricity Step 5: Calculation of Steel Weight. ( IS: 456-2000 ). Hence, diameter of bar, thickness of slab, effective depth and spacing are co. 1. SECTION 5: CONCRETE STRUCTURES 5-5. 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. Distribution Bar = 12 Number of The Distribution Bar. Base slab width b= 0. This method is applicable to straight and right (i. The minimum reinforcement spacing is based on maximum size of aggregates, so that concrete can be placed and compacted properly. 960 x 16 =. For Min Steel: 3d ——— Where. (1:1. Provide main reinforcement of 10 mm diameter bars at 120 mm c/c. 4. 5. spacing of reinforcing bars (cls. 1 Cement 5. 11. 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. Important Point: As per IS 456:2000, the limit on minimum reinforcement along either direction has been specified. 7. 2 mm. Distribution bars are provided perpendicularly with the top of the main bar. 0018 times the slab's gross area, but the maximum spacing of the bars differs. ) = 200. Only 2. It covers the general features of design, loads and load combinations, structural analysis, materials, fabrication, erection and maintenance. 3. 15 % of the gross area if a mild steel bar is used. 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. 6. 6. 7. b. The shear resistance in a R. 2 of IS 456) shall not exceed 140/8 = 17 mm is also satisfied with the bar diameters selected here. 3. 5. 11. Spacing should not exceed smaller these two values. There are 51 nos of main bars are required for the slab. 1. How to Design Concrete Structures to Eurocode 2 - Chapter 2: Getting started. however with a maximum spacing of 4. 150m = 150 mm. bars at 400 mm o. 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. Adequacy of curing. 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. 3. Lapping is not allowed for the bars having diameters more than 36 mm. 667’ x 40. 5. 3). 10mm Ø hor. Distribution Reinforcement) Class B (Not Top Bars) J, NThe span requirement for the slabs is given by ACI Code 8. For interior Spans: According to the code, the moments can be distributed according to factores shown in the figure: II. 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. 3. Section 8. The spacing shall be less than five times the slab’s adequate depth, or 450 mm in the distribution bars. Minimum Bar Size : 16 mm Maximum Bar Size : 25 mm Top Footing Minimum Bar Size : 16 mm Top Footing Maximum Bar Size : 25 mm Pedestal Minimum Bar Size : 16 mm Pedestal Maximum Bar Size : 25 mm Minimum Bar Spacing : 100. 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. 2, or >0. TRANS REINF - Reinforcement required along the transverse direction ( along local Y axis of the plates ). 5. 3. Spacing =150mm. 3. C. reinforcing parallel to load per inch of slab width perpendicular to load / slab thickness) (steel yield stress)) f. In case of mild steel, minimum reinforcement along either direction shall not be less than 0. The diameter of the reinforcements and the spacing of bars are to be used according to the (cls. 12. 3. There are also new provisions for integrity reinforcement. 5, the lateral spacing of the flexural bars should not exceed three times the thickness of 18 inches. Mainly used in slab and footing, it is the most significant part of raft foundation. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. For longitudinal bars in columns of size more than 200 mm. design wheel load. 6H to 0. 2 of IS 456), the maximum spacing is the lesser of 5d or 450 mm i. = constant used to compute V c in slabs and footings. per 1 m 2. The spacing between longitudinal reinforcement of the column should be the greatest of the following: 4 cm; 1. Self-weight of the slab = 3. 5. Lesser dimension bars are used. The manual design process included the reinforcement calculation for the main. 3. 460/2=1. There are no SHGC requirements in the Marine Zone. 12. 1 or the bottom bars required by 8. 5tf or 0. For Edge Spans : Static Mom. Main Steel – 3d or 300 mm whichever is smaller. of chair bars = Area of structural reinforcement in sqm / chair bar per sqm. The Distribution bars will be 8 mm in diameter with 125 mm c/c spacing. Spacing: ϕ8 mm: ϕ10 mm: ϕ12 mm: ϕ16 mm: ϕ20 mm: 100: 502 : 785: 1130: 2010: 3141: 125: 402:. 2—Construction load factorsThe diameter of the main bar should not be less than 8mm for the HYSD bar and 10mm for plain bars. The ACI 318-19 provides a number of requirements regarding slab thickness, concrete cover, and reinforcement ratio which facilitate the design process. t 12mm stirrups at 150mm ctrs Two terminated bars A A Elevation Section A-A Lsy. and the clear spacing between the bottom bars a = 60 mm. Refer to EN 1994-2, Clauses 6. 3. 10. Design Guide on the ACI 318 Building Code Requirements for Structural Concrete. It brings economy to the design of. 2 For one-way shallow foundations, two-way isolated footings, or two-way combined. 12% of high yield strength deformed bars. 4 bar at the top and the bottom of the footing or one No. 1—Reinforcement for shrinkage and temperature. The slab is supported all around walls of width 300 mm. is the strength reduction factor as specified by table 21. 96 x 1000 / 1536 = 130. 2. Slab concrete ratio less than M15 grade. Ensure that the return bars at the edge of the slab are a minimum of ¼ (15%) of the length of the adjoining span. 6H, and 0. however we need to understand the requirement of chair. 2. 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. In. for industrial slabs that carry distribution. Wall Load Per Running Meter. Distribution bars:-These bars are straight bars. 1-1 and its accompanying notes, except as modified herein. Providing 20mm diameter bars @130mm spacing C/C. Current recommended. 25 in. Tech. 12 % of the gross area if the HYSD bar (Fe415) is used. 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. b) For design of distribution bar/Transverse bar. It is appropriate to design the slab per unit width, hence b = 1000mm. 3. There is two spacing between 3 reinforcement and 50 mm length both side of 1st and 3rd reinforcement used in footing. So, Provided area of steel reinforcement, Ast=2416 mm 2. 8. Sub-Grade and. The span requirement for the slabs is given by ACI Code 8. Proportioning of flat slabs: As per cl. 9) Prepare bar bending. Difference Between Main Bars. FIrst, find number of rods required for main reinforcement and distribution. Distribution steel –5d or 450 mm. We would like to show you a description here but the site won’t allow us. and 𝑓𝑦 = 276 𝑀𝑃𝑎 for main and temperature bars. 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. Roof drainage system (Adapted from the International Code Council). But even after that If d,provided < d,reqd, slab thickness is to be increased and check for deflection is to be satisfied. 140 M. 2. Solving for the Number of Reinforcement Chair required per square meter: Since the chair reinforcements support only the top layer, then we will consider the weight of top mesh reinforcement as dead load. correct. Total length = 3. 10 cm; 12 cm; 14. 7. 3. 2. , and if the lap length is taken as 50d, then. If it is desired to replace 10 mm bars by 12 mm bars, then the spacing of 12 mm bars should be. 4. ACI 318-19, Table 8. Wood structural panels with a minimum thickness of 7 / 16 inch (11. steel bars. Abstract. 5. A distribution bar is equal to (total slab length- 2x clear cover length)/center to center spacing of the bars + 1. Nos of Bars =. Modify ACI 318 Sections 17. The minimum spacing between the two bars can be about 50–75 mm. For longitudinal bars in slabs. As per IS 456: 2000, Cl. Step 1- Calculation of Numbers of Bars.