Diameter of top and bottom distribution bars = 16 mm. 1. The Clear. For concrete cast against and permanently. Check for the depth. 2. 7—Post-tensioning load redistribution Chapter 4—Strength adequacy of concrete slabs and formwork, p. The maximum reinforcement ratio for columns is 0. 5 b w d): For longitudinal bars bent at 45 degrees, the second equation above is replaced by S max =3d/4The spacing of distribution bars having diameter 10 mm should be 9 inches to 12 inches center to center c/c. vapor retarders - some times referred to as vapor barriers, insulation, etc. What are the different functions of distribution bars in concrete . 3. This reinforcement is reported in terms of area required per unit width of slab. 1. For ASTM A 497 deformed welded wire fabric Values in the subgrade drag equationData of Calculate Steel in Rcc Slab-. Q) Calculate the quantity and weight of steel rod in a one-way slab having length 6 m, width 2. 14 x 5 x 5 = 78. the quality and basic shape of reinforcement bar shall be specified. Grade of concrete ƒck, Grade of Steel ƒy, Concrete cover, Clear long spam, Clear short spam, With of supporting beam, Live load, Floor finish load, The diameter of the main and distribution bar, and; Assume the. Slabs - - - maximum spacing is 3*deff or 300mm whichever less side ) of the deformed bar ( see Note ) NOTE - In accordance with IS : 1139-1966. the square of the thicker slab when f=0. The length of a distribution bar on the south side will be the same as the north side. The design method is followed as per Annexure D of IS 456:2000. 6 Reinforcement 5. 5 bar is permitted to be located at either the top of the slab or bottom of the footing. 6. 7. 3. Select the correct answer using the codes given below: A. 3. thick slab, the maximum joint spacing should be limited to 12 to 15 ft. The maximum spacing should be reduced by a factor of 0. For longitudinal bars in columns of size more than 200 mm. e. 1 mm) and maximum panel span of 8 feet (2438 mm) shall be permitted for opening protection in buildings with a mean roof height of 33 feet (10 058 mm) or less that are classified as a Group R-3 or R-4 occupancy. As per IS 456: 2000, Cl. Additionally, the clear space between the transverse bars and lapped bars may not exceed 1. 2. and 𝑓𝑦 = 276 𝑀𝑃𝑎 for main and temperature bars. 00mm Maximum Bar Spacing : 250. 3. For instance, the ACI 318-19 specifies minimum slab thickness that satisfies deflection. Note: When ACI 318-19 is selected, an additional size effect factor λs is added in the above equations, λs is a function of effective depth of the slab d, and is calculated per Equation (22. S. 8. The slab has to carry a live load of 4 KN per meter square. slabs, walls, and joists - #14 and #18 bars - ½ inch; Slabs, walls, and joists - #11 bars and smaller - ¾ inch ; Beams and columns. 7. 3. , i. 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. This is also satisfied for all the bars. 347. = constant used to compute V c in slabs and footings. 3. member :. For ASTM A 497 deformed welded wire fabric Values in the subgrade drag equation Data of Calculate Steel in Rcc Slab-. 2 times effective depth b. 2 mm. 2. 40 mm or diameter of bar whichever is more 2. 2 d t kips in. 3. = 2sqm/1sqm = 2nos. TWO WAY SLAB DESIGN SPREADSHEET:Fig 10: Reinforcement of a slab. 5. bars at 400 mm o. Business, Economics, and Finance. According to Clauses 8. 6. Assume diameter of bars and calculate spacing of bars. 2) For main bars, maximum spacing is restricted to 3 times effective depth or 300. 460/2=1. 7. 2. 1-4. Also useful for attaching stirrup bar effectively. Radius = 2. *A4 size is 210 x 297 mm. Distribution Bars are used to hold the slabs on either way and to resist the cracks. Unit weight formula for kg per metre = (D2/163) × L kg/m. If the reinforcing bars do not extend beyond the critical section. ratio of flexural stiffuess. 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. 4. 3. Diameter of Distribution Reinforcement Bars = d d =12mm. Larger areas, lower loads, and higher seismic zones. 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. 12. This reinforcement is reported in terms of area required per unit width of slab. There are also new provisions for integrity reinforcement. According to ACI Code 7. 20 square inch (129 mm 2) in cross-sectional area shall be provided: 1. , the effective depth is: clear spacing between layers clear cover stirrup diameter bar diameters 2 dh . 2. iv) Detrmine Sapcing of bars at critical section based on designed value of Ast by selecting appropriate bar dia. 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. of Main bars = (3000)/150 + 1. 4 Splices in reinforcement. Spacing should not exceed smaller these two values. How to Design Concrete Structures to Eurocode 2 - Chapter 7 : Flat slabs and Figure 6. 2, The diameter of reinforcing bars shall not exceed one-eighth of the total thickness of the slab. 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. 11. 19. Total Length of Distribution Bars = 19. 5-2 Recommended spacing of transverse. b) In partially prestressed superstructure: In tension zone it shall not be less than that calculated as per Sections 12 and/or 16 (whichever is higher) of IRC:112. The diameter of the chair bar should not be less than 12 mm. Figure: Contraction joint;. 5 and 6. One Way Slab Bar Bending Schedule Calculation. 5. of chair bars = Area of structural reinforcement in sqm / chair bar per sqm. 11. how to calculate the number of rebar in an exceedingly circular block. 960 x 16 =. Provided at the bottom of the slab. Provide main reinforcement of 10 mm diameter bars at 120 mm c/c. 7. Structural Design 1 - Design of Reinforced Concrete Structures REFERENCES/COURTESY 1) IS 456 : 2000 — Plain and reinforced concrete – Code of practice 2) S Unnikrishna pillai and. bars at every 3 layers of chb finished surface corner wall detail 1 - 10mm Ø vert. Crack Control – when crack widths are not checked by calculations No Further Checked Required. 4 Deck Overhangs for guidance on deck slab bars. per Section 6. as per ACI 318. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. 12. 4. 10mm Ø hor. Cryptocritical section of the slab is just outside the outside edge of the beam supporting the slab. For distribution bars, the maximum spacing is specified as 5 times the effective depth. 5 inches, and the transverse bars must be fully developed in grouted masonry at the point where they cross the lapped reinforcement. Design the slab using the data given below; Purpose of building – Residential. 7. 3. 12% of high yield strength deformed bars. Number of Distribution Bars = Lx / spacing + 1 = 3000/150 + 1 = 21 nos. Leg of Chair= (2 * spacing of bottom main bar) + 50Plain 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. Cranking is also used in two way slabs. Tech. Anchor bolts are located a minimum of 1 3 / 4 inches (45 mm) from the edge of the concrete parallel to the length of the wood sill plate. According to ACI Code 7. e. But even after that If d,provided < d,reqd, slab thickness is to be increased and check for deflection is to be satisfied. For a given area of tension steel areas, the distribution of steel reinforcement affects. Rebar steel will be calculated for the bending moments “Mx” and “My. Special surface finishes, including coatings. Minimum number of reinforcing bars required. Only 2. Breadth of Footing = Y = 1. 4: Two-way slabs having multiple spans; The purpose of the code is to design the total amount of reinforcement steel rebar into principal directions in the slab system. No. Weight of Distribution Bar= d²/162. 3. cm. 6. The maximum spacing of minimum steel (distribution bars) is the lesser of 5(135) and 450 mm. general building code. 5 Loads on Supporting Beams 25 COMPRESSION MEMBERS 25. Concrete Slab Design ProcedureSteel reinforcements can be use, however with a maximum spacing of 4. Bar Spacing. 5 times effective depth d. spacing of bar/prestressing strand etc. The distribution bars provide the following functions in slab construction: 1. Minimum reinforcement is ensured in slab (in both directions) to take care of shrinkage, thermal movements and. And, in compression zone, same as in (a) above. 4. Basically slab is the horizontal member which is rests on the beam section. 2 and 26. The code requires this value to be the minimum of these three values. The code itself suggests that the diameters can be #3, #4 and #5. 3. Unbonded Cross Sections" for discussion. 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. c. This smaller amount of reinforcement0. Development Length (Ld) = 40d. For example, for 12mm. 1 Definitions 25. correct. 200= 6. 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. Clause 6. M. Spacing of Main Reinforcement: The maximum spacing of bars shall not exceed. 4. 12% gross c/s of slab – for HYSD bars; Spacing of distribution bars. spacing of reinforcing bars (cls. Total Length of Distribution Bars = 786. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. thick slab will increase the potential for random or out-of. • Maximum spacing of shrinkage or temperature bars shall not exceed the lesser of 5ℎ and 450 𝑚𝑚 • Specified concrete cover of primary reinforcement for cast-in-place slabs not exposed to weather or in contact with ground 36 mm∅ bar and smaller is 20 𝑚𝑚; and 16 𝑚𝑚 for precast slabs (see NSCP Table 420. 60. There are 51 nos of main bars are required for the slab. Abstract. 5. c) Slab reinforcement percentage less than 0. Ex. 5 m as per IRC. One Way Slab Bar Bending Schedule Calculation. 11. 5 bar is permitted to be located at either the top of the slab or bottom of the footing. e. NOTATION All notations and definitions are the same as defined in Chapter 2 of the Code. For Main Bar. f ck = 25 Mpa. 04𝑥1000 𝑆= = = 272. 2. 3 only and there is no need to perform specific checks on the bar spacings to control cracking. 3. 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. 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. The slab is. Step 1- Calculation of Numbers of Bars. in. 3(d) and 17. Continuity of reinforcement shall be provided at corners and intersections. To calculate: Spacing of replaced 12mm. This portion is coming at the top of the bottom main bar. 140 M. 1,2 and 3 B. 10. Number of Main Bar & Distribution Bar: First, we have to calculate the number of bar required for the slabs. The slab is supported all around walls of width 300 mm. The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. 08 times the gross area of the column. reinforcing parallel to load per inch of slab width perpendicular to load / slab thickness) (steel yield stress)) f. C. Consider 28 Nos. 6—Factors affecting the construction load distribution 3. 6. Dia of Bar to be provided 'd' = 16 mm (round bar) Area of cross-section of 1 bar = 0. 3. 17 The design of one-way slab is simple and can be carried out easily. Use #4 bars at 25-inch spacings center to center each way, As = 0. LL = 6. vapor retarders - some times referred to as vapor barriers, insulation, etc. Total Length of Distribution Bars = 786. 15 % of the gross area if a mild steel bar is used. 3m. 1. Spacing of Main Reinforcement: The maximum spacing of bars shall not exceed. 6% of the gross wall area for Grade 60 or Grade 40 bars, respectively. Head of Chair: Length of head = (2 * spacing of distribution bar) + (2 * 50) = (2 * 150) + (2 * 50) = 400mm. As = 0. 5d or 450 mm whichever is smaller for distribution steel. ACI 318-19, Table 8. 5 Spacing limits and concrete cover for reinforcement shall be shown on the design drawings. 50 8. (1) Deformed steel bars will be overlapped for a distance of at least 24 bar diameters measured from the tip of one bar to the tip of the other bar. Since diameter of bar = 10 mm. spacing of bars should not be more than. First, find number of rods required for main reinforcement and distribution. In the. 3 or larger placed within the last 8 inches of each end of the lap (Figure 3). Provided at the top of the slab. 2 Effective Length ofCompression Members 25. Calculate The Cutting Length of the Chairs Bar Given Data. Workmanship and jobsite conditions. 2(5)In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. AS3600-2009 P P Lsy. In general we use 5 inch (125mm) thick slab, if thickness of slab is 125mm,then maximum diameter of bar used in slab is 125/8 which is equal to 16mm. 5. Now we have to calculate the depth from maximum moment values. Distributed reinforcement is a bar spacing applied over a polygon area. 75 m. Minimum number of reinforcing bars. Bar Bending Schedule Of Slab (Two Way) Ly/Lx = Longer span/Shorter span = 5000/3000 = 1. 2. Provide main reinforcement of 10 mm diameter bars at 120 mm c/c. Distribution Reinforcement) Class B (Not Top Bars) J, NThe span requirement for the slabs is given by ACI Code 8. >EAST side. Load Distribution. Different codes have different formulas to calculate crack spacing and width developed in flexural members. The spacing of distribution bar should not be greater than 5 times the effective thickness of slab or 450mm whichever is smaller. 7. 25 in. 5 mm 2. 0m from the fixed end. 3. The maximum spacing of bars shall not exceed. c 0. 5. 3% (100As/bd < 0. 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. 5. According to Clauses 8. Learn More Estimate this Slab (Drawing Included) STEP 5. 3-Main bar Bottom Area Given data. 7. Assume 𝑓𝑐′ = 27. No. If shear reinforcement is required for in-plane strength, spacing of longitudinal reinforcement shall not exceed l w /3. 33=16 no’s. (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. 6. Sub-Grade and. Fig. The minimum cover for cast-in-place concrete is specified by the ACI 318 Building Code. 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. 1 of IS 456:2000, the reinforcement in either direction ,in slabs shall not be less than 0. for interior walls. 7. 5, the lateral spacing of the flexural bars should not exceed three times the thickness of 18 inches. BS EN 1992–1–1 section 7. , 300 mm. 7. 5 bar or two No. design wheel load. 6—Reinforcement limits 8. 2. 3. 4. / 0. As per clause 26. 4—Construction load distribution 3. 1905. length of. 1 Spacing s of longitudinal bars in cast-in-place walls shall not exceed the lesser of 3h and 18 inches. Number of Required Bars Formula = (Length of slab / spacing) + 1. 12. slab known as a joist system can be constructed without any shear reinforcement in the joist ribs. The minimum and maximum spacing reinforcement in concrete structural members such as beams and slabs. 6 For two‐way slabs, maximum spacing of bars shall not exceed two times the slab thickness h nor 450 mm. 21Two-Way Slabs 6 b- Distribution of the total factored static moment to negative and positive moments: I. 2. Max BM = wl 2 /8 = (14. 002 times the gross cross-sectional area of the footing. 1. 4—Openings in slab systems 8. Lapping is not allowed for the bars having diameters more than 36 mm. per 18-in. 6. As many of these requirements would need to be repeated in Chapters 3 through 14, placing such requirements in only one location eliminates code development coordination issues associated with the same requirement in multiple locations. 3. 7. 2 to read as follows:Historically, this level of precompression was found to enhance the performance of punching shear in two-way flat slabs based on tests conducted with this level of precompression. If a closer spacing of bars is required at the columns, as per Section 13. No. No of Bars/m 2 = Factored Load / Pcr. Opposite length of bar = 2950. 1. 1. 1) The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. Spacing between bars = 0. Step 1: – Calculate numbers of distribution rods. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less. The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. 1 of IS 456), the maximum spacing is the lesser of 3d and 300 mm i. Chapter 9 which is also per mitted per ACI 349-06 Appendix D. The minimum percentage of reinforcement is 0. 1 and 24. 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. In case of mild steel, minimum reinforcement along either direction shall not be less than 0. and floor finishes 1 KN per meter square. 1. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. 00mm Pedestal Clear Cover (P, CL) : 50. It brings economy to the design of. 2. 2. 5. 376Kgs For Floor slab -2 (One way slab) :-As per the above figure Floor slab -2 is a One way slab. No. 3. t 12mm stirrups at 150mm ctrs Two terminated bars A A Elevation Section A-A Lsy. The no. slabs) or. Calculation of ratio of the length of long span to length of short span. = 16 mm, spacing @ 150 c/c. 2Dead Load + 1. 5db). 2 Specific requirements for QA Stockists 26 4. Use #4 bars at 25-inch spacings center to center each way, As = 0. 5. IS 456: 2000 CONTENTS PAGE SECTION 1 GENERAL J SCOPE 2 REFERBNCES 3 TERMINOLOGY 4 SVMBOU SECTION 2 MATERIALS, WORKMANSHIP, INSPECTION ANDTESTING 5 MATERIALS 5. The minimum and maximum spacing reinforcement in concrete structural members such as beams and slabs are required as per standard codes. Spacing required = Area of 1 bar x 1000 / (Ast req. Refer to Section 5. 3. (ii) The pitch of the bars provided to act as distribution bars or bars provided to guard against temperature and shrinkage in an R. 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. 2 (8) Beams: the maximum transverse spacing of the legs in a series of shear links s t,max; 9. Load Calculation: Live Load = 2 kN/m 2. 1 specifies the requirements of ACI 7. 6. The thickness of Slab – 150 mm. 9 m = 3. The Main bars will be 12 mm in diameter with 100 mm c/c spacing. Thickness of Slab = 0.