7. iv) Detrmine Sapcing of bars at critical section based on designed value of Ast by selecting appropriate bar dia. 7. 890m. Effective Depth: (130-15-10/2) = 110 mm. 7—Post-tensioning load redistribution Chapter 4—Strength adequacy of concrete slabs and formwork, p. critical section of the slab is just outside the outside edge of the beam supporting the slab. 12. From clause 26. According to ACI Code. per 18-in. e. from deviations in bar spacing and bar size are shown in figure 5. Additionally, the clear space between the transverse bars and lapped bars may not exceed 1. Weight of the bar as per their length and. 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. Step 4 – Extra Top Bar. If the maximum diameter for slab thickness is 75 mm, so the diameter of reinforcing bars should be 8 mm. 6. 3. No of bars = (opp length/spacing) + 1. The maximum diameter of the reinforcing bar in a slab should not exceed 1/8th of the total thickness of the slab. 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. Distribution bar 8 mm C/C 140 mm Length 1. 3. TRANS REINF - Reinforcement required along the transverse direction ( along local Y axis of the plates ). 6. 6. Thus, the requirement threshold of 125psi (0. Side clear cover of slab 25 mm; Thickness of slab is. general building code. 18/100× × 100× D = 0. This type of reinforcement is convenient for modeling beam reinforcement. 6H to 0. 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. Figure-2: Distribution or shrinkage and Temperature Reinforcement Bars in One-way Concrete Slab. 7. slabs) or integral with slab with depth greater of 2. however with a maximum spacing of 4. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. 2) For main bars, maximum spacing is restricted to 3 times effective depth or 300 mm whichever is smaller. / 0. In case of mild steel, minimum reinforcement along either direction shall not be less than 0. EXAMPLE: Suppose we have a one-way slab, which has a length of 5 m or a width of 2 m (clear span). rainfall intensity in inches per hour for the building location specified in the plumbing code. That is 11′. Minimum Reinforcement Ratio in Slabs. Clear cover = 25mm (top and bottom ) Thickness = 150mm. Maximum spacing of tension bars (all slabs) In accordance with clause 7. 1. 2—Minimum flexural reinforcement in prestressed slabs 8. From a study that compared voided slabs and solid slabs, researchers observed that for typical bays of 7. 7. 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. Question: Question 11 Not yet answered Marked out of 1. 6. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. The distribution bars number 17 in total. 1. 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. 04𝑥1000 𝑆= = = 272. It brings economy to the design of. 5m . 090 square inches per foot of slab width, required each way. 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. This is also satisfied for all the bars. and 𝑓𝑦 = 276 𝑀𝑃𝑎 for main and temperature bars. Main bar = 12mm@150mm c/c. (Main Bar & Distribution Bar Difference) Top and Bottom Clear Cover is 25 mm. c. If the reinforcing bars do not extend beyond the critical section. dia. 4 bar at the top and the bottom of the footing or one No. The main bars will be 12 mm in diameter @100 mm c/c spacing. d = Effective depth. Minimum number of reinforcing bars required. 2 Use Φ12 bar c/c 250mm 2. , and ℓw/3. For Min Steel: 3d ——— Where. 5 Loads on Supporting Beams 25 COMPRESSION MEMBERS 25. from deviations in bar spacing and bar size are shown in figure 5. In case of HYSD bars, minimum reinforcement along either direction shall not be. M o can be distributed, according to factors given in the table 8. bar due to its non-availability. Design size and spacing of dowel bars at an expansion joint of concrete pavement of thickness 20 cm. 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. 5] = 120 mm c/c. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. If the maximum diameter for slab thickness is 75 mm, so the diameter of reinforcing bars should be 8 mm. design wheel load 4000 kg. Head of Chair: Length of head = (2 * spacing of distribution bar) + (2 * 50) = (2 * 150) + (2 * 50) = 400mm. C. 4 mm. 3. 2. Conclusion. S. 33=16 no’s. MOM-X – Longitudinal moment, corresponding to which LONG. Distribution bars:-These bars are straight bars. The size of the stirrups should be chosen to avoid a closer spacing. 3 Direct supply of steel reinforcing bars to site by QA Manufacturer 27 Section 5 Purchasers testing 28 5. The maximum spacing should be reduced by a factor of 0. 12. The primary reinforcing bar is placed perpendicular to the bigger side or parallel to the shorter direction to give suitable support. Base slab width b= 0. 2: Alternate method for showing two-way slab reinforcement reinforcing bars should be clearly scheduled on the drawings. For distribution bars, the maximum spacing is specified as 5 times the effective depth. 14. Breadth of Footing = Y = 1. Bar cranking is the process of bending up the bottom steel bars in upward direction. 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. Wood structural panels with a minimum thickness of 7 / 16 inch (11. For longitudinal reinforcement in columns of size 200 mm and less, with 12 mm diameter bars as longitudinal steel. 3(d) and 17. 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. 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. 0 8 #5 12 6 5 2 4. 3 only and there is no need to perform specific checks on the bar spacings to control cracking. 5 mm 2. 15 mm or diameter of bar. design wheel load 4000 kg. 3% (100As/bd < 0. Heavy loads. Total length of bar required for distribution bars of Floor Slab 1 = 131m. A s,min,reqd ≥ b*h*0. e. 5φVc except for the following cases: A. Distribution Bar = 10 mm, Spacing – 150 mm c/c, Alternate bent up. 6 𝑀𝑃𝑎. No of Bars/m 2 = Factored Load / Pcr. 26. 3. 4—Openings in slab systems 8. Cutting length= 9000 – 2 x 50 =8900 mm =8. For 8 mm diameter bar 7 inches to 9 inches center to center c/c. For distribution bars the maximum spacing is specified as 5 times the effective depth or. Anchor bolts are embedded into concrete a minimum of 7 inches (178 mm). The spacing of distribution bar should not be greater than 5 times the effective thickness of slab or 450mm whichever is smaller. 1—Minimum flexural reinforcement in nonprestressed slabs 8. Proportioning of flat slabs: As per cl. Main Steel – 3d or 300 mm whichever is smaller; Distribution Reinforcement for. VARIATION AMONG BETWEEN MAIN BARS AND DISTRIBUTION BARS: 1. Provide main reinforcement of 10 mm diameter bars at 120 mm c/c. 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. × c/c distance between the top distribution bar) + (extra length on either side of the top distribution bar)]Calculate the nos’ of facet rebar. The steel reinforcement in SS/NS wall and slab shall be welded steel fabric mesh for steel bar diameter of up to 16mm and hot rolled steel bars. FIrst, find number of rods required for main reinforcement and distribution. Distribution Reinforcement) Class B (Not Top Bars) J, NThe span requirement for the slabs is given by ACI Code 8. 3. In both cases, the minimum bar areas are equal to 0. Diameter of Distribution Reinforcement Bars = d d =12mm. 12, apply only to one-way slabs (all code sections cited hereinafter are from ACI 318-08): “7. 2. 667’ x 40. (b) For No. Lower part bar will be worked by maintaining cover with spacer. Full bond Full bond h/2 Filler Figure 15:3: Contraction joint 15. , 450 mm. Flexural tension reinforcement shall not be terminated in a tension zone unless (a), (b), or (c) is satisfied: (a) Vu ≤ (2/3)ϕVn at the cutoff point. 5 The lateral spacing of temperature and shrinkage reinforcement should not be placed farther apart than 5 times the slab thickness or 18 inches according to ACI code 7. of chair bars = Area of structural reinforcement in sqm / chair bar per sqm. Now we have to calculate the depth from maximum moment values. Size of the bar is less than the main bar. 1 of IS 456), the maximum spacing is the lesser of 3d and 300 mm i. áTie the bars at the top and the bottom irrespectively. 12. 1. = 16mm, spacing @ 150 c/c. 5—Application of the simplified method 3. , and if the lap length is taken as 50d, then. Given, Length of longer span = 5000 mm. 6m . 3. Provided to resist the shear stress and cracks. Provided to resist the bending stress. 285+150. 17 x 10 6 )/ (1000 x 119 2 x 25) = 0. Given data: Distribution bar dia. Now, we will calculate the length of the three parts of the chair bar separately. (2× Spacing of distribution bar) + (2×25) = (2 x 150) + ( 2 x 25) = 350 mm . 26. 6 For two‐way slabs, maximum spacing of bars shall not exceed two times the slab thickness h nor 450 mm. 4 bar at the top and the bottom of the footing or one No. 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. 7. 896 x Total Length (where d is in # Nos. The spacing < 300mm and <3*d as per Cl. 3. 13. 1. Spacing of Main reinforcement bars = s m = 150mm c/c. Bars shall not be smaller than No. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. Main Steel – 3d or 300 mm whichever is smaller. 2 to read as follows:In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. 15% gross c/s of slab – for MS bars; 0. 5, which equals 51. There are 51 nos of main bars are required for the slab. For longitudinal reinforcement in beams. Load Distribution. cm. 20 square inch (129 mm 2) in cross-sectional area shall be provided: 1. The dowel bars are provided in the direction of. The minimum and maximum spacing reinforcement in concrete structural members such as beams and slabs are required as per standard codes. Unit weight for feet per metre = (D2/ 533) × L kg/ft. 7. 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. 2. 6—Factors affecting the construction load distribution 3. The larger the diameter of the bar, the more the spacing is, and vice versa. Step 1. 5. 2 of IS 456 :2000 , the reinforcing bars shall not exceed 1/8 of theHow to Design Concrete Structures to Eurocode 2 - Chapter 7 : Flat slabs and Figure 6. 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. Spacing = 150mm c/c as per given details = (6000/150) + 1. 5% or 0. three times the effective depth of solid slab or; 300 mm; whichever is smaller. The max. 2. 6. 5 bar is permitted to be located at either the top of the slab or bottom of the footing. BBS of One Way Slab. 6m. Concrete Slab Design ProcedureSteel reinforcements can be use, however with a maximum spacing of 4. Is 1200 Important Point Part-1; IS Code for Civil Engineer [Q&a]. For columns exposed to weather or contact with the ground and embedded bars are No. Development length = 40d. Weight of Distribution Bar=64/162. Minimum reinforcement is ensured in slab (in both directions) to take care of shrinkage, thermal movements and. 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. 3. Check spacing of bars. the joint spacing should be 24 to 30 times the pavement thickness with a maximum spacing of 15 ft (4. As = 0. Clear cover (top & bottom) = 50 mm. If we increase the spacing beyond 200mm the column section buckling effect will occur. “D” bars (Distribution bars) - Longitudinal bars in the bottom mat of deck reinforcement. 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. 5. the value of the calculated k is far below the limiting k’ for slabs. What is the minimum number of main steel bars provided in RCC?the transverse wire or bar and the transverse joint, will not exceed 3 inches or one-half of the wire or bar spacing in the fabric or mat. 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. 25What is the maximum diameter of reinforcement/ bar used in slab as per IS 456: 2000:- there are two types of reinforcement/ bar provided in RCC slab, 1) main bar provided in tension zone of RCC slab and 2) distribution bar provided in compression zone. 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. 7. 21Two-Way Slabs 6 b- Distribution of the total factored static moment to negative and positive moments: I. A = roof area in square feet drained by the drainage system. 1. It is a two way slab. R4405. 4 MoVEMEntS And rotAtIonS: 4. What are the different functions of distribution bars in concrete . 1 Purchaser’s tests of steel reinforcing bars 28 Section 6 Methods of testing 32 6. Concrete cover = 25 mm. 0018 times the slab's gross area, but the maximum spacing of the bars differs. 2. Lesser dimension bars are used. 8. Distribution of Main Bars. NOTE 3 - In co1 3. It is a useful reference for engineers, planners and contractors involved in bridge construction. 5. 2R-8 4. 6. 1 of IS 456:2000, the reinforcement in either direction ,in slabs shall not be less than 0. 2—Flexural reinforcement spacing 8. AS3600-2009 P P Lsy. 4. Slab Thickness = 150 mm. 3. 3 b) 1). Cranking is also used in two way slabs. To calculate: Spacing of replaced 12mm. 1 of IS 456:2000, the reinforcement in either direction ,in slabs shall not be less than 0. b. 4 Slabs Spanning in Two Directions at RightAngles 24. 3. In Flat plate slab the, distribution bars are arranged in one direction at Top of main bar (in longer span). Bars shall not be smaller than No. f. 12. Step 1. Distribution bars are provided in the longer span direction. 715m long, and it is supporting a blockwork load at 1. = 2sqm/1sqm = 2nos. 6. Distribution Bar = 1800 -2 (75) ÷ 150 +1. C slabs. Chair bar per square meter. 2 to read as follows:Top & bottom distribution bar dia. bars in two-way slabs. 83 mm. as per ACI 318. 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. 10 cm; 12 cm; 14. Number of Main Bars = Ly / spacing + 1 = (4000/150) + 1 = 27 nos. The number of the bars is seventh factor taken in basic rules in column design. 5. 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. 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. for a 6 in. The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. The minimum spacing between the two bars can be about 50–75 mm. 8. 3 – When spacing of tendons exceeds 54 in. Minimum distribution reinforcement steel (for TOR Steel) shall be 0. Slab concrete ratio less than M15 grade. For rectangular footings bars in long direction should be uniformly spaced. 2. 1 In slabs, beams and girders, splices in reinforcement at points of maximum stress shall be avoided wherever possible. Minimum Reinforcement Ratio in Uniform Footing. 5. Height of block wall = 2. 8 ACI 318 , Section 17. 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. No. 5 Spacing limits and concrete cover for reinforcement shall be shown on the design drawings. 1. If redistribution is carried in design, the allowable max spacing needs to be reduced or relaxed as per table 15 of IS456. 3. 3. Step 2: Preliminary dimensioning. 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. Radius =length /2. 5. 3 Factored live load = 3. 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. The maximum spacing between stirrups is smallest of the following provided that (V s <0. 5 bar is permitted to be located at either the top of the slab or bottom of the footing. AASHTO 5. For interior Spans: According to the code, the moments can be distributed according to factores shown in the figure: II. Diameter of the Main reinforcement bars = d m = 12mm. 3. how to calculate the number of rebar in an exceedingly circular block. Size of the bar is higher than the distribution bar. Design the slab using the data given below; Purpose of building – Residential. 6. ACI 7. Spacing =80mm. 5. 5—Application of the simplified method 3. 6. b) Slab depth does not exceed 200 mm when the steel grade is 460. Given, Cranked bars or Main bar of diameter 16 mm and center to center spacing 150 mm. 2, 17. 4—Construction load distribution 3. bars at every 3 layers of chb finished surface corner wall detail 1 - 10mm Ø vert. Chapter 9 which is also per mitted per ACI 349-06 Appendix D. 10 the minimum bar spacing for bundled bars shall be calculated based on the derived diameter instead of calculating from individual. But even after that If d,provided < d,reqd, slab thickness is to be increased and check for deflection is to be satisfied. = constant used to compute V c in slabs and footings. 5d or 450 mm whichever is smaller for distribution steel. Tech degree in Civil Engineering with six specializations, i. Distributed reinforcement is a bar spacing applied over a polygon area. 2. 12% of the overall sectional area. 2. 12% gross c/s of slab – for HYSD bars; Spacing of distribution bars. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. 1. Refer to Section 5. 2, also includes guidance on achieving enhanced aggregate interlock by continuing a small percentage of deformed reinforcement (0. The cross‐sectional area of one N28 bar is As = 620 mm2 and with N12 stirrups at 150 mm centres, Atr = 110 mm2. 7. The code makes it explicit that the diameters of the skin bars are not involved in determining the spacing of this reinforcement. normally lower dia rebar tends to more sagging while placing in top layer. 6. 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. of distribution bars = Ly/Spacing + 1 = 2000/150 +1 = 14. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. For distribution bars the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is less. k’ = 0. Dowel bars are typically placed at the mid-depth of the slab and should be parallel to the pavement surface and parallel to the direction of travel. 2 or 8. 64 2 )/8 = 23. The slab is not. 11 bars and smaller, continuing reinforcement provides double the area required for flexure at. 1 of IS 456), the maximum spacing is the.