12% of high yield. FIrst, find number of rods required for main reinforcement and distribution. 3. A minimum of three bars evenly placed in the lap length is required. 5—Application of the simplified method 3. e. As per IS 456: 2000, clause 26. 26. 04𝑥1000 𝑆= = = 272. Special surface finishes, including coatings. 6. 25𝑚𝑚 𝐴𝑠 415. 15 % of the gross area if a mild steel bar is used. with 12mm. e. These were developed for slabs of “ordinary” proportions supporting gravity loads, and they may not be sufficient to intercept potential punching shear cracks in thick transfer slabs, podium slabs, and mat foundations. The transverse bar must be No. Adequacy of curing. GameStop Moderna Pfizer Johnson & Johnson AstraZeneca Walgreens Best Buy Novavax SpaceX Tesla. 304. Cutting Length: = total length — 2 x clear cover = 4000 - 2 x 20 = 3960 mm or 3. In case of HYSD bars, minimum reinforcement along either direction shall not be. 12. = 20 mm, spacing @ 150c/c. 12% of cross-sectional area as distribution rebars as per. A cantilever slab 200 mm thick is 1. 34 kg ——– (1) Section 1 Total = 33. 1. Bar Spacing. The punching shear capacity is obtained via the ACI code equations, seen below. 10. It covers the general features of design, loads and load combinations, structural analysis, materials, fabrication, erection and maintenance. Take à l/d as 32 for HYSD bars . L is the required length of the Steel bar of Diameter D. Requirements regarding dowel bars and spacing of joints have been modified. Development length = 40d. M o can be distributed, according to factors given in the table 8. 1. 5. Waist slab Bar Bending Schedule. For distribution bars the maximum spacing is specified as 5 times the effective depth or. e. Diameter of a chair bar should not be less than 12mm. 6. 960 x 16 =. 3. 2. 2. To distribute the superimposed load to the main bar. 2). 67 m, the slab depth for the voided slabs ranged from 10 inches to 16. According to Clauses 8. Reinforcement details bay C-D, 1-2. Distribution of Main Bars. Calculation of number of distribution bars. 9, page 341. 25*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. Chair bar per square meter. Distribution bars of diameter 12 mm and center to center spacing 150 mmm. All values are taken except ‘D’ in the above formula. c. Cranking is also used in two way slabs. 1. 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. Distribution bar 8 mm C/C 140 mm Length 1. 5. three times the effective depth of solid slab or; 300 mm; whichever is smaller. Top & bottom distribution bar dia. 5 mm 2. t 12mm stirrups at 150mm ctrs Two terminated bars A A Elevation Section A-A Lsy. exposed to earth or weather. Here we have to calculate the number of main bar and distribution bar. Exceptions: 1. 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. Unit weight of concrete = 25 kN/m 3. 8. ,). 7. Basically slab is the horizontal member which is rests on the beam section. slabs) or. 15% gross c/s of slab – for MS bars; 0. 4. They ensure that the load is not concentrated in one area, which could cause cracking or failure. Here, ∅ is the bar diameter. 16. Minimum number of reinforcing bars. 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. . Minimum Reinforcement Ratio in Uniform Footing. 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. LL = 6. , addi-tional bonded shrinkage and temperature reinforcement conforming to 7. 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. 1. 5d = 5 * 130 = 650 mm. Now. 3 Required Strength 4-2. Clear Cover = 20 mm. The maximum spacing of main bars, as given in cl. 15%of gross cross-sectional area if plain bars are used and 0. 6 Live Load. 1. 2, The diameter of reinforcing bars shall not exceed one-eighth of the total thickness of the slab. Learn More Estimate this Slab (Drawing Included) STEP 5. Thickness of Slab – 150 mm. What Is The Maximum Bar Spacing In Reinforced Beams According To IS 456? Normally this. Load Distribution. What is the maximum spacing of a distribution reinforcement to be used in a one way slab as per IS 456? b. The spacing of the chair bars depends on several factors which are listed below: – Diameter of the bar used in making a chair. 8 say 16 nos. cm for 1 m width of slab where D is the overall depth of slab. In case of mild steel, minimum reinforcement along either direction shall not be less than 0. 12. The maximum diameter of the reinforcement bars in R. It is also important to keep slabs as square as possible. The minimum cover for cast-in-place concrete is specified by the ACI 318 Building Code. Type and spacing of the control and construction joints. So may be in this case, chair may be required more. 21Two-Way Slabs 6 b- Distribution of the total factored static moment to negative and positive moments: I. = 175 mm Last perimeter, from column face, min. 5% steel (continually reinforced) as described in Section 8. a) Slab depth does not exceed 250mm when the steel grade is 250. 304. Number of Main Bars = (Length of Longer Side / Spacing) + 1 =. For interior Spans: According to the code, the moments can be distributed according to factores shown in the figure: II. The maximum spacing of reinforcement at critical design sections for positive and negative moments in both the middle and column strips shall not exceed two times the slab thickness (ACI Code Section 13. Radius =length /2. 4. 1 of IS 456:2000, the reinforcement in either direction ,in slabs shall not be less than 0. 715m long, and it is supporting a blockwork load at 1. Total Length of Distribution Bars = 19. The spacing of the bars The length of a distribution bar on the south side will be the same as the north side. Near lapped joints, if the diameter of the longitudinal bar is greater than 14 mm. f. Now assume diameter of bars and calculate spacing between bars. 6. For Edge Spans : Static Mom. 2. unless otherwise noted, all slabs on grade are to be reinforced with 10mm bars at 400mm o. Bar cranking is the process of bending up the bottom steel bars in upward direction. The minimum and maximum spacing reinforcement in concrete structural members such as beams and slabs are required as per standard codes. IF Grade 50 to 60 deformed bars or welted wire reinforcement are used9. Section 8. 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. 20 square inch (129 mm 2) in cross-sectional area shall be provided: 1. 5 m). Top & bottom clear cover = 50 mm. 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. 4. If dowel placement deviates from the desired position, it is said to be misaligned. Important Point: As per IS 456:2000, the limit on minimum reinforcement along either direction has been specified. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. Number of bar = 2150/150+1= 15. 2and3 C. Note that required A s must be furnished in each direction. 133 square inches per foot). 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. 7. 1123 mm. 3. 8. 167 for 15% redistribution. 2. 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. Main Steel – 3d or 300 mm whichever is smaller; Distribution Reinforcement for. 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. If the reinforcing bars do not extend beyond the critical section. 3(d) and 17. 6. length of dowel bar and a maximum joint opening of 0. 6. 3. 7. 1. 5. Provided to resist the shear stress and cracks. Slab steel bar spacing maximum 150mm c/c. Consider 28 Nos. 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. 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. 2. steel bars. Slabs - - - maximum spacing is 3*deff or 300mm whichever less side ) of the deformed bar ( see Note ) NOTE - In accordance with IS : 1139-1966. Reinforce concrete for a 5-inch thick concrete slab: For a 5-inch thick slab, #4 (1/2-inch diameter) rebar is commonly used. 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. 2 BS 8110-1:1997) Width of the beam = 500mm = 0. dia. 1. 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;. 3. 3. S. 26. 2 – Spacing of tendons shall not exceed 6 feet. and the clear spacing between the bottom bars a = 60 mm. Two-Way. (table 15). 3 times effective depth c. To calculate: Spacing of replaced 12mm. Fig. Maximum spacing: The maximum spacing of main bars is limited to 3d or 300 mm (whichever. 7. 2—Flexural reinforcement spacing 8. Design of the footing cantilever slab portion (per meter strip) Note that the bending moment in the slab is maximum. 7. Exceeding a joint spacing of 15 ft. = D1=10mm. BS EN 1992-1-1 Annex 1 1. 9. ACI 7. 2. is the strength reduction factor as specified by table 21. Height of block wall = 2. Note * rationalise centre of bars in column strips T2 and B2 to 175 mm centres to suit punching shear links. 2, 17. Check for the depth. But even after that If d,provided < d,reqd, slab thickness is to be increased and check for deflection is to be satisfied. 2) For main bars, maximum spacing is restricted to 3 times effective depth or 300. For columns exposed to weather or contact with the ground and embedded bars are No. Longitudinal reinforcement should not be less than 0. 3-Main bar Bottom Area Given data. Spacing: ACI Code 7. 5 try 100 mm Dead load Slab weight = 2. slab, shall not. Proportioning of flat slabs: As per cl. Tech. Maximum spacing of tension bars (all slabs) In accordance with clause 7. The maximum spacing of bars shall not exceed. 0m from the fixed end. member has shallow depth of less than 200 mm (ex. = 16 mm, spacing @ 150 c/c. 5bw and 600 mm B. 7. Modify ACI 318 Sections 17. 4H to 0. 5% or 0. 6 𝑀𝑃𝑎. 17 x 10 6 )/ (1000 x 119 2 x 25) = 0. 6 = 17. According to ACI Code 7. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. ([DPSOH ± 'HWHUPLQDWLRQ RI Seismic Forces: Diaphragms of %XLOGLQJ Chapter 4 One-way Slabs 4. The reinforcing bars must extend into the slab beyond the critical section for a required length. 15 mm or diameter of bar. f ck = 25 Mpa. 1-3). (c) Deep beams in accordance with 9. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. 6. Actual variety of 1 sides rebar =Number of main bar – rebar of the middle. BS EN 1992–1–1 section 7. t + D Chair bar per square meter. 3. 54 * 1000 / 180 = 436. Number of Distribution Bars = Lx / spacing + 1 = 3000/150 + 1 = 21 nos. For slabs 200 mm thick or greater, the bar size and spacing should be limited to control the crack width and reference should be made to Section 7. It is a useful reference for engineers, planners and contractors involved in bridge construction. DESIGN OF SLAB: Design of typical Floor Slab: We have thickness of slab as 130 mm. Given the radius of relative stiffness of 90 cm. Some discussion to decide about max spacing: AS per IS 456: Maximum spacing for bars in beams is 180mm for Fe415 grade and 150mm for Fe 500 grade reinf. L 1 = (2 x spacing of distribution bar) + (2 x the clear cover). Before calculating the cutting length, we need to calculate each part length of chair bar. . 13. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. The maximum spacing of reinforcement in slabs is 3d or 300mm(minimum of both). The design of a one-way slab can be done by using the Indian standard code. 1905. 2, The diameter of reinforcing bars shall not exceed one-eighth of the total thickness of the slab. The. = 2sqm/1sqm = 2nos. As per IS 456: 2000, Cl. the maximum spacing between two secondary parallel bars in case of RCC Slab shall be 5d or 450 mm or whichever is less. Lesser dimension bars are used. 3. IN Downloaded from Ktunotes. Important Points. 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. 1 or the bottom bars required by 8. Total length of Foundation Distribution bar =No’s of bar x cutting length. The format for each example follows the format of the ACI Design Handbook, SP-17, and provides a reference to the Code paragraph for each calculation procedure. 2 (7) Beams: the maximum longitudinal spacing of bent-up bars s b,max; 9. If the reinforcing bars do not extend beyond the critical section. 2. The previous code that allowed up to Grade 520 was changed to Grade 550, and related regulations were modified. unless otherwise noted in plans or specifications, camber all r. 3, 1) The horizontal distance between parallel main reinforcement bars shall not be more than. 4. If the maximum diameter for. (b) Horizontal reinforcement at least 0. Concrete floor slabs on grade are subjected to aIn steel reinforcement binding wire required is 8 kg per MT. 7 For temperature steel only, maximum spacing shall not exceed five times the slab thickness h nor 450. 890m. So, provide spacing of distribution bar equal to. 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. 2—Minimum flexural reinforcement in prestressed slabs 8. The clear cover is 30 mm ( top to bottom ) and the thickness of the slab is 150 mm. The reinforcing bars must extend into the slab beyond the critical section for a required length. 78′ Say, 19′. 3. 2 or 8. 10. Distribution Reinforcement bar: No of bars = total span/spacing = 2960 mm/200 mm = 15. For structural slabs of uniform thickness the minimum area of tensile reinforcement in the direction of the span is: For US-units: IF Grade 40 to 50 deformed bars are used. Check for Cracking. Total Length of Distribution Bars = 19. 2 For one-way shallow foundations, two-way isolated footings, or two-way combined. 2. 5] = 120 mm c/c. Having <0. Max BM = wl 2 /8 = (14. 8. Given the radius of relative stiffness of 90 cm. M. R403. 3. 11. 34 kg Section 2-1. 4. Hence, diameter of bar, thickness of slab, effective depth and spacing are co. 2. properly jointed slab. Calculate The Cutting Length of the Chairs Bar Given Data. for exterior walls or 30 in. Bar crank. Lesser dimension bars are used. 10mm Ø hor. So, provide spacing of. Main Bar = 12 mm, Spacing – 150 mm c/c, Alternate bent up. 2. 12% of the total cross sectional area , when HYSD bars Fe415 are used. 2 or 8. 4. 2. 285+150. 6m. 1 or the bottom bars required by 8. Minimum number of bars for a square column are 4 and for circular column are 6. 096 square inches per foot (or #4 bars at 18 inches center to center to meet ACI criteria, As = 0. The primary reinforcing bar is placed perpendicular to the bigger side or parallel to the shorter direction to give suitable support. The thickness of Slab – 150 mm. is lapped with a lower bar of 20mm dia. The dowel bars are provided in the direction of. 6. 3 b) 1). c. Distribution of Main Bars. Dia of Chair. Figure 3:. Maximum Spacing between Stirrups . Clause 6. A = roof area in square feet drained by the drainage system. Provided at the bottom of the slab. BASIC THUMB RULE FOR RETAINING WALL DESIGN-Base slab thickness not less then 0 (H= Total height of retaining wall)The bottom part of the chair bar is called the leg of the chair bar. Modify ACI 318 Sections 17. Distribution Reinforcement for Stairs. The Main bars will be 12 mm in diameter with 100 mm c/c spacing. Depth of footing = 750 mm. 4. 167, hence it is singly reinforced. 3. 3. In general we use 5 inch (125mm) thick slab, if thickness of slab is 125mm,then maximum diameter of bar used in. 2. 3% (100As/bd < 0. The length of a distribution bar on the south side will be the same as the north side. and the clear spacing between the bottom bars a = 60 mm. a) Slab depth does not exceed 250mm when the steel grade is 250. Suppose we have a one way slab,which having a length 5 m or width 2 m (clear span). 10m , Depth of Slab = 0. Minimum reinforcement is ensured in slab (in both directions) to take care of shrinkage, thermal movements and. 305. Other Standards ACPA T 253-21 Standard Method of Test for Dowel Bars for Concrete Pavement AWWA C213-07 Fusion-Bonded Epoxy Coating for Interior and Exterior of Steel Water Pipeline (American Water Works. . 1 and 24. 2. (c) Deep beams in accordance with 9. Provided at the bottom of the slab. 2. The maximum spacing should be reduced by a factor of 0. 0 8 #5 12 6 5 2 4. AS3600-2009 P P Lsy. The minimum percentage of reinforcement is 0.