If the maximum diameter for slab thickness is 75 mm, so the diameter of reinforcing bars should be 8 mm. Factor affecting spacing of chair bars. Height of block wall = 2. For ASTM A 497 deformed welded wire fabric Values in the subgrade drag equationData of Calculate Steel in Rcc Slab-. Provide main reinforcement of 10 mm diameter bars at 120 mm c/c. Step 1. 5. 2. 7. of Main bars = 20 + 1 = 21 Nos. normally lower dia rebar tends to more sagging while placing in top layer. Heat de-velopment can also be reduced by ad-Cutting length = clear span of the slab + (2 x Ld) + ( 2 x 0. ACI 7. Now, we need to replace the distribution bar of 10mm. Spacing between bars = 0. Weight of Distribution Bar= (8)²/162. 1. Given, Length of longer span = 5000 mm. 4. 2) For main bars, maximum spacing is restricted to 3 times effective depth or 300 mm whichever is smaller. TWO WAY SLAB DESIGN SPREADSHEET:Fig 10: Reinforcement of a slab. Since diameter of bar = 10 mm. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. Design ProcedureAllowable clear spacing of bars = 3d = 3(170) = 510 mm Actual clear spacing = 300 – 10 = 290 mm < 3d → ok Figure 3. 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. Breadth of Footing = Y = 1. 3. Main bar = 12mm@150mm c/c. Sub-Grade and. 5. ? 1. The maximum spacing of main bars, as given in cl. 3. , and ℓw/3. 4. 78′ Say, 19′ >WEST side. 12% of the gross cross-sectional area if HYSD bars (Fe 415) are used. 2 Symbols Relating to Shape of the Bar Along Its Length As per IS 456: 2000, Cl. The no. 19 or greater, the minimum concrete cover is 5 cm. HYSD bars for upto M45 grade concrete and 0. 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. Total length of bar required for distribution bars of Floor Slab 1 = 131m. of chair bars = Area of structural reinforcement in sqm / chair bar per sqm. bars in two-way slabs. 2) b = edge distane of bar for calculation of lap length (cl. = 2sqm/1sqm = 2nos. 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. Tech. 1 or the bottom bars required by 8. 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. Q) Calculate the quantity and weight of steel rod in a one-way slab having length 6 m, width 2. Exceptions: 1. 318-081, Section 7. Additionally, the clear space between the transverse bars and lapped bars may not exceed 1. Lesser dimension bars are used. Conclusion. A cantilever slab 200 mm thick is 1. The minimum spacing between the two bars can be about 50–75 mm. 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. Use M20 Concrete and 415 steel. Special surface finishes, including coatings. dowel misalignment levels of less than 1 in. c. bars at every 3 layers of chb finished surface corner wall detail 1 - 10mm Ø vert. 5. 2—Flexural reinforcement spacing 8. 002 times the gross cross-sectional area of the footing. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. Consider the ACI 318-14 code according to which the Ø is the strength reduction factor as specified in table 21. For Edge Spans : Static Mom. 2. Conclusion. 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. As per clause 26. 960m. 2. (15) Step Spacing of the dowel bars. 89m. 10m , Depth of Slab = 0. f. 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. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. If the reinforcing bars do not extend beyond the critical section. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. , 300 mm. spacing of bars should not be more than. 0020. It is mainly to prevent upward bending moment near the joint. 96 x 1000 / 1536 = 130. Reinforcing Bars for Crack Control 6-33 Distribution of Tension Reinforcement in. Spacing of Main Reinforcement: The maximum spacing of bars shall not exceed. 3. / 0. Thus, the requirement threshold of 125psi (0. , 300 mm. Step 2: Calculate cutting length of main bars and distribution bars. 3(d) and 17. 12% of high yield. 08 times the gross area of the column. Side clear cover of slab 25 mm; Thickness of slab is. As bar is placed in longer span which is 4m. Distribution bars are provided in the longer span direction. • Maximum area of main steel in slab = 4% 𝑜𝑓 𝑏𝐷 (As per ACI). Length of waist slab= L. 3—Corner restraint in slabsColumn = Self Weight x Number of floors. , Structural. 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. Cutting length= 9000 – 2 x 50 =8900 mm =8. 1: The prime functional requirement of a joint is to cater for movements with very low resistance or with no resistance at all. 3. Five times the effective depth of slab, and; 45 cm. 1 of IS 456:2000, the reinforcement in either direction ,in slabs shall not be less than 0. Also useful for attaching stirrup bar effectively. àIn case the thickness of slab is 120mm, the height of bent bar should be 60mm. 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. Main Steel Bars. 7—Post-tensioning load redistribution Chapter 4—Strength adequacy of concrete slabs and formwork, p. The length of a distribution bar in west side is the same as the east side. 11. 21Two-Way Slabs 6 b- Distribution of the total factored static moment to negative and positive moments: I. Modify ACI 318 Sections 17. For ASTM A 497 deformed welded wire fabric Values in the subgrade drag equation Data of Calculate Steel in Rcc Slab-. however with a maximum spacing of 4. Cutting Length: = total length — 2 x clear cover = 4000 - 2 x 20 = 3960 mm or 3. e. Distribution Bar = 12 Number of The Distribution Bar. 7. 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. 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. EXAMPLE: Suppose we have a one-way slab, which has a length of 5 m or a width of 2 m (clear span). 6. 6. 7. Sub-Grade and. Unit weight formula for kg per metre = (D2/163) × L kg/m. = 2sqm/1sqm = 2nos. 67’ Weight of Distribution Bars = d 2 /52. , and if the lap length is taken as 50d, then. 667’ x 40. Bars shall not be smaller than No. 5. W = 3. 8. 3. 7 For temperature steel only, maximum spacing shall not exceed five times the slab thickness h nor 450. Ld = Development length of the bar. 9. In case of HYSD bars, minimum reinforcement along either direction shall not be. 1. 2 and 9. So, provide spacing of. c. Here we have to calculate the number of main bar and distribution bar. Unbonded Cross Sections" for discussion. 3. 5. It is a two way slab. 1 QA Stockist’s certification of steel reinforcing bars 25 4. 1. Full bond Full bond h/2 Filler Figure 15:3: Contraction joint 15. total angular change of tendon profile from tendon jacking end to point under considerations, radians. Number of Main Bars = (Length of Longer Side / Spacing) + 1 =. Step 4 – Extra Top Bar. 3%. Whichever is smaller,. cm. Ensure that the return bars at the edge of the slab are a minimum of ¼ (15%) of the length of the adjoining span. Provided to resist the bending stress. 12% of cross-sectional area as distribution rebars as per. and : 1786-19667, the nominal size of the deformed bar is equivalent to the diameter or side of a plain bar having the same weight per metre run as the deformed bar. The diameter of the reinforcements and the spacing of bars are to be used according to the (cls. 4. Now we have to calculate the depth from maximum moment values. Minimum distribution reinforcement steel (for TOR Steel) shall be 0. (c) Deep beams in accordance with 9. 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. - M. 3. 8 say 16 nos. 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 b) 1). Width of the Slab = 2 m = 2000 mm. 75 m. The minimum and maximum spacing reinforcement in concrete structural members such as beams and slabs. 890m. Bar Spacing. 090 square inches per foot of slab width, required each way. It is mainly to prevent upward bending moment near the joint. 3 Design of the slab (per meter strip) Bending moment on the slab is maximum at the face of the column (in this case at the face of the upstand beams) (clause 3. The dowel bars are provided in the direction of. However, it is not a code, so many engineers do use portions of ACI 318 on their projects. 3. Head ( E ): The length of the head = [(2nos. Number of Required Bars Formula = (Length of slab / spacing) + 1. For distribution bars the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is less. correct. e. This spacing should be reduced by a factor of 0. , Chapter 12 c c = clear cover of reinforcement, in. Adequacy of curing. Unit weight of concrete = 25 kN/m 3. 5 m). per 18-in. 26. 1 of IS 456), the maximum spacing is the. 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. C. Inclined length = 0. Other notations, wherever used, areQuick guide to design of one way slab – with IS Code 456:2000. 18D sq. 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. 54 * 1000 / 180 = 436. Bar cranking is the process of bending up the bottom steel bars in upward direction. Number of Main Bars = (Length of Longer Side / Spacing) + 1 = (6000/150)+1. Nos of Bars =. STEP. 6. Design the slab using the data given below; Purpose of building – Residential. unless otherwise noted, all slabs on grade are to be reinforced with 10mm bars at 400mm o. 2 As per NSCP 2015, a minimum shear reinforcement in concrete design shall be provided in all regions where Vu > 0. In ACI 350R-89, the recommended minimum S&T reinforcement for walls with movement joint spacing greater than 60 ft (18. 6 𝑀𝑃𝑎. 2) For main bars, maximum spacing is restricted to 3 times effective depth or 300 mm whichever is smaller. critical section of the slab is just outside the outside edge of the beam supporting the slab. Bar Bending Schedule Of Slab (Two Way) Ly/Lx = Longer span/Shorter span = 5000/3000 = 1. The term "standard hook" as used in this Code shall mean one of the following: (a) 180o. For instance, the ACI 318-19 specifies minimum slab thickness that satisfies deflection. Sawcut Joints A typical SOG includes three different types of joints, described in detail in ACI 360R Chapter 5. Concrete floor slabs on grade are subjected to aIn steel reinforcement binding wire required is 8 kg per MT. Near lapped joints, if the diameter of the longitudinal bar is greater than 14 mm. Reinforcement details bay C-D, 1-2. the maximum spacing between two secondary parallel bars in case of RCC Slab shall be 5d or 450 mm or whichever is less. Step 1: – Calculate numbers of distribution rods. Slab steel grid not less than Fe500. from deviations in bar spacing and bar size are shown in figure 5. The punching shear capacity is obtained via the ACI code equations, seen below. 3(1) of IS 456, is the lesser of 3(135) and 300 mm. Distribution Reinforcement for Stairs. Calculate the quantity of. The shear resistance in a R. 2) For main bars, maximum spacing is restricted to 3 times effective depth or 300. Provided at the bottom of the slab. 7. Note that required A s must be furnished in each direction. 6. 3. You just enter your information in the yellow colour box for the design of two way slab excel sheet as per is 456 such as. Reinforcement chairs should be made with a minimum of 12 mm bar. iv) Detrmine Sapcing of bars at critical section based on designed value of Ast by selecting appropriate bar dia. 1. thick slab, the maximum joint spacing should be limited to 12 to 15 ft. 6. The code itself suggests that the diameters can be #3, #4 and #5. 2. 200= 6. 225m. 1. The span requirement for the slabs is given by ACI Code 8. 24 SOLID SLABS 24. 67 m, the slab depth for the voided slabs ranged from 10 inches to 16. 1. 3. TRANS REINF - Reinforcement required along the transverse direction ( along local Y axis of the plates ). C. The slab is supported all around walls of width 300 mm. A s,min,reqd ≥ b*h*0. Difference Between Main Bars. × c/c distance between the top distribution bar) + (extra length on either side of the top distribution bar)]Calculate the nos’ of facet rebar. For distribution bars the maximum spacing is specified as 5 times the effective depth or 450 mm. Maximum Spacing between Stirrups . 3. They ensure that the load is not concentrated in one area, which could cause cracking or failure. , i. Spacing of chairs should be per 1 m or 1 no. and floor finishes 1 KN per meter square. Clear cover (top & bottom) = 50 mm. 20 square inch (129 mm 2) in cross-sectional area shall be provided: 1. Given, Cranked bars or Main bar of diameter 16 mm and center to center spacing 150 mm. Design procedure. 25 x 87. Spacing s of longitudinal bars in precast walls shall not exceed the lesser of (a) and (b): (a) 5h. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. 1% steel allows sawed contraction. 9) Check for shear ( using Table 19 of code IS 456:2000). cb = smaller of (a) the distance from center of a bar or wire to nearest concrete surface, and (b) one-half the center-to-center spacing of bars or wires being developed, in. Actual variety of 1 sides rebar =Number of main bar – rebar of the middle. 7. 1 Purchaser’s tests of steel reinforcing bars 28 Section 6 Methods of testing 32 6. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. 3 ANALYSIS 3. 1. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. #IScodes #Concrete #Concretetechnology Recent & Related Videos Concrete. 7. The slab requires 51 main bars. 6. Distribution bars are 8 mm in diameter @ 150 mm centre to centre spacing. Spacing: ACI Code 7. The depth of voided slabs could reduce the height of the structural system up to one foot per floor compared. C. For slabs less than 200 mm thick the following maximum spacing rules apply: For the principal reinforcement: 3h but not more than 400 mm. 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. , 1-hr. Load Distribution. That is 11′. One Way Slab Reinforcement Detail. 2—Minimum flexural reinforcement in prestressed slabs 8. Step 1. 3. 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. For distribution bars, the maximum spacing is specified as 5 times the effective depth. 2 of IS 456), the maximum spacing is the lesser of 5d or 450 mm i. 4. Dia of Main Bar=16mm. The new formulas are more complex and consider more parameters, such as bridge length and. Effective depth=d provided =120-20-4= 96 mm. Step 1- Calculation of Numbers of Bars. 4. ment among different types of cements. 896 x Total Length (where d is in # Nos. 14 x 5 x 5 = 78. As the slab is inflexibly fixed at the ends, this shrinkage will be limited by the support, which will prompt liable tensile stress in the slab. Weight of Distribution Bar= d²/162. 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. No. 300mm. 304. The Main bars will be 12 mm in diameter with 100 mm c/c spacing. Clear Cover = 20 mm. k’ = 0. Given the radius of relative stiffness of 90 cm. 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. 2. 2). 1. 12. Ex. As always, local service records are the best guide for determining trans verse joint. The thickness of Slab – 150 mm. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. 5d = 5 * 130 = 650 mm. 10. b. 6m . and 𝑓𝑦 = 276 𝑀𝑃𝑎 for main and temperature bars. Bar cranking is the process of bending up the bottom steel bars in upward direction. Before calculating the cutting length, we need to calculate each part length of chair bar. 6. 5φVc except for the following cases: A. 5. Where a slab on ground is cast monolithically with the footing, one No. 2R-8 4. e. R403.