2 Specific requirements for QA Stockists 26 4. the total length of the leg is 2×spacing +50. bars at 400 mm o. Near lapped joints, if the diameter of the longitudinal bar is greater than 14 mm. Bar schedule for Slab; Table 3 : Bar schedule for SlabArea of single bar = (3. For distribution bars the maximum spacing is specified as 5 times the effective depth or 450 mm whichever is less. 7. The punching shear capacity is obtained via the ACI code equations, seen below. 5. Development length =40d . 2. 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. i = 100-yr. 12% of cross-sectional area as distribution rebars as per. Is 1200 Important Point Part-1; IS Code for Civil Engineer [Q&a]. 5 M from the edge of wall and at both ends 6 mm plain M. For eg. for industrial slabs that carry distribution. Select the correct answer using the codes given below: A. 4. 12. 2: Alternate method for showing two-way slab reinforcement reinforcing bars should be clearly scheduled on the drawings. No of Bars/m 2 = Factored Load / Pcr. ' = 1536 sq mm. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. 4—Openings in slab systems 8. 7. 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. reinforcing parallel to load per inch of slab width perpendicular to load / slab thickness) (steel yield stress)) f. 8. NOTATION All notations and definitions are the same as defined in Chapter 2 of the Code. The wires or bars will be lapped as follows. Additionally, the clear space between the transverse bars and lapped bars may not exceed 1. iv) Detrmine Sapcing of bars at critical section based on designed value of Ast by selecting appropriate bar dia. 1 for minimum thickness of non-prestressed two-way slabs without interior beams is revised to include Grade 550. 26. Main Steel – 3d or 300 mm whichever is smaller. The spacing or c/c distance of distribution bars shall not exceed the following. Slab steel bar not less than 10mm dia. 75 m. 1 and 24. , addi-tional bonded shrinkage and temperature reinforcement conforming to 7. All values are taken except ‘D’ in the above formula. (b) For No. e. 1. Tech. Roof drainage system (Adapted from the International Code Council). 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. 3. 6 For two‐way slabs, maximum spacing of bars shall not exceed two times the slab thickness h nor 450 mm. A cantilever slab 200 mm thick is 1. 3). 785 x d^2 = 0. 7. This reinforcement is reported in terms of area required per unit width of slab. According to Clauses 8. member has shallow depth of less than 200 mm (ex. assume corners are held down. 25*3. 2 mm. 14 x r x r) = 3. 3. VARIATION AMONG BETWEEN MAIN BARS AND DISTRIBUTION BARS: 1. 2, can form no closer to the facesee table 3 for spacing. 3. 1. Provided at the top of the slab. Unit weight of concrete = 25 kN/m 3. 34 kg ——– (1) Section 1 Total = 33. 3. B. is for dowel diameters to be one-eighth of slab thickness, dowel spacing to be 12 in. , 300 mm. 67’ Weight of Distribution Bars = d 2 /52. 1 or the bottom bars required by 8. joint spacing greater than 50 ft (15. 25 kN/m 2. There are no SHGC requirements in the Marine Zone. 9) Prepare bar bending. 3 Slabs-on-ground with turned-down footings. 896 x Total Length (where d is in # Nos. 4. 11 bars and smaller, continuing reinforcement provides double the area required for flexure at. 5 h Finding out bar spacing: Let us chose # 3 bar (0. 5 mm 2. Anchor bolts are embedded into concrete a minimum of 7 inches (178 mm). REINF is calculated. 3 – When spacing of tendons exceeds 54 in. According to ACI Code 7. 5. 24 SOLID SLABS 24. 6 in the following cases; In sections within a distance equal to 4 × thickness of wall above or below a beam or slab. Exceeding a joint spacing of 15 ft. In case of mild steel, minimum reinforcement along either direction shall not be less than 0. , addi-tional bonded shrinkage and temperature reinforcement conforming to 7. 1-4. 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. 26. and the clear spacing between the bottom bars a = 60 mm. 2. Step 1 – Find out the Total Number of Main Bars & Distribution Bars. bars in two-way slabs. 7. As discussed earlier, assume that the beam is reinforced with two layers of #11 reinforcement and clear spacing between layers = 1 in. 15% of the total cross-sectional area of the slab (bD). 2. 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. What is the maximum spacing of a distribution reinforcement to be used in a one way slab as per IS 456? b. Maximum diameter of the bars (cl. How to Design Concrete Structures to Eurocode 2 - Chapter 7 : Flat slabs and Figure 6. 76 Slab designation: CS1 Check if one-way or two-way slab 1 Slab is one way since it is catilever slab Minimum slab thickness min t = 69. 2. The length of a distribution bar on the south side will be the same as the north side. The dowel bars are provided in the direction of. Calculate Steel Quantity for Slab. As per clause 26. 3. The minimum spacing between the two bars can be about 50–75 mm. 10. The minimum eccentricity values as per IS 456 code provision is calculated by using below formula in the column design we need to consider minimum or greater than 20 mm value as eccentricity value. The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. 7. 12. 15 % of the gross area if a mild steel bar is used. Concrete cover to main reinforcing bars shall be provided per AASHTO Table 5. For rectangular footings bars in long direction should be uniformly spaced. the quality and basic shape of reinforcement bar shall be specified. It covers the general features of design, loads and load combinations, structural analysis, materials, fabrication, erection and maintenance. Basic considerations. 9. 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;. The spacing < 300mm and <3*d as per Cl. Depth of footing = 750 mm. The reinforcing bars must extend into the slab beyond the critical section for a required length. 1 - 10mm Ø vert. 3 Slabs-on-ground with turned-down footings. 7. Learn More Estimate this Slab (Drawing Included) STEP 5. c. Lesser dimension bars are used. however we need to understand the requirement of chair. Temperature distribution due to heat of hydration and internal stresses caused by outside cooling in a free standing concrete block. 5d = 5 * 130 = 650 mm. Size of the bar is higher than the distribution bar. 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. 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. Chair bar per square meter. So, provide spacing of distribution bar equal to. Total Cutting Length Of Rod = 2nos x 1. 2. where a is the radius of the wheel load distribution in cm and h is the slab thickness in cm. Diameter of top and bottom main bars = 20 mm. 26. 2—Construction load factorsThe diameter of the main bar should not be less than 8mm for the HYSD bar and 10mm for plain bars. 4 Deck Overhangs for guidance on deck slab bars. Calculation of the loads. Provide 0. Total Load on Slab (Dead Load + Live Load +Wind Load + Self-Weight) Besides this above loading, the columns are also subjected to bending moments that have to be considered in the final design. 1 given below by the ACI 318-14 code. To calculate: Spacing of replaced 12mm. For main bars, maximum spacing is restricted to 3 times effective depth or 300 mm whichever is smaller. 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. One Way Slab Reinforcement Detail. 12 x 100cm x D cm=0. 12% of the gross cross-sectional area if HYSD bars (Fe 415) are used. 133 square inches per foot). LL = 6. The spacing of distribution bar should not be greater than 5 times the effective thickness of slab or 450mm whichever is smaller. What Is The Maximum Bar Spacing In Reinforced Beams According To IS 456? Normally this. 6 Reinforcement 5. 2 As per NSCP 2015, a minimum shear reinforcement in concrete design shall be provided in all regions where Vu > 0. Figure: Contraction joint;. (Main Bar & Distribution Bar Difference) Top and Bottom Clear Cover is 25 mm. Refer to EN 1994-2, Clauses 6. C. A cantilever slab 200 mm thick is 1. In slabs constructed with lift-slab methods where it is impractical to pass the tendons required by 8. 4. Hence, diameter of bar, thickness of slab, effective depth and spacing are co. • The. Total wt of Bars = 150. AASHTO 5. 60. Design size and spacing of dowel bars at an expansion joint of concrete pavement of thickness 20 cm. The slab has to carry a live load of 4 KN per meter square. àIn case the thickness of slab is 120mm, the height of bent bar should be 60mm. Chapter 9 which is also per mitted per ACI 349-06 Appendix D. = D1=10mm. The maximum spacing of reinforcement in slabs is 3d or 300mm(minimum of both). Conclusion. Transverse joint spacing should not exceed 125% to 150% of the longitudinal joint spacing. No. 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. b. Wood structural panels with a minimum thickness of 7 / 16 inch (11. Distribution bars are placed on the top of the. Development length = 40d. 3. Head ( E ): The length of the head = [(2nos. The reinforcing bars must extend into the slab beyond the critical section for a required length. Total Length of Distribution Bars = 786. Spacing should not exceed smaller these two values. Always main bar use in shorter span. 0020. For instance, the ACI 318-19 specifies minimum slab thickness that satisfies deflection. ACI 318-19, Table 8. Designing and drawing of flat slab with the help of i. 2. , 0. Check for Cracking. 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. The Distribution bars will be 8 mm in diameter with 125 mm c/c spacing. to carry a uniform live load of 7500 Pa. Number of Main Bars = (Length of Longer Side / Spacing) + 1 =. Difference Between Main Bars. 1. In ACI 350R-89, the recommended minimum S&T reinforcement for walls with movement joint spacing greater than 60 ft (18. 96 sq mm. 7. You can design the two way slab using our android application. In Flat plate slab the, distribution bars are arranged in one direction at Top of main bar (in longer span). 2 or 8. Calculation for distribution bar: Bending moment for distribution. The length of a distribution bar in west side is the same as the east side. The distribution bars number 17 in total. 3 Slenderness Limits for Columns 25. 12% of the overall sectional area. slab along the shorter span, 3mm per meter span. Whichever is smaller,. The manual design process included the reinforcement calculation for the main. Distribution steel –5d or 450 mm whichever is smaller Where, ‘d’ is the effective depth of slab. 2. 6. 8. of bars = { (L or w – concrete cover for both sides) ÷ spacing} +1 Equation 8. 97 kN/m 2. Given Data: Height of footing = 600 mm. 1 Overview 4-1 4. So, provide spacing of. 6. spacing of reinforcing bars (cls. The manual design process included the reinforcement calculation for the main bars and distribution bars as per the considerations and as per the problem statement. total angular change of tendon profile from tendon jacking end to point under considerations, radians. 1 or the bottom bars required by 8. 2 and 26. Distribution Bar. the value of the calculated k is far below the limiting k’ for slabs. 5 and 6. 1 Definitions 25. 3. The minimum percentage of reinforcement is 0. Generally, a #4 (1/2″) diameter reinforcing bar with a minimum grade of 40 is used for standard residential slabs. The diameter of the reinforcements and the spacing of bars are to be used according to the (cls. 3. ACI 360R, Section 6. For distribution bars (cl. 8% and more than 6% of gross C/S. from deviations in bar spacing and bar size are shown in figure 5. They ensure that the load is not concentrated in one area, which could cause cracking or failure. Wood structural panels with a minimum thickness of 7 / 16 inch (11. To firmly hold the main bars in their. The Clear cover will be 25 mm (Top or Bottom) and the thickness of the slab will be 150 mm. Distribution Reinforcement for Stairs. The number of bars is 50. Weight of rod per meter length = d 2 /162 where. 15%of gross cross-sectional area if plain bars are used and 0. For 8 mm diameter bar 7 inches to 9 inches center to center c/c. however with a maximum spacing of 4. This change affects the calculation of minimum slab thickness for fy exceeding Grade 420. The maximum diameter of the reinforcing bar in a slab should not exceed 1/8th of the total thickness of the slab. Refer to Section 5. 1. 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. 2. 5bw and 600 mm B. That is: 19′. 1% steel allows sawed contraction. 93 m 2 ) = 469. 4 bars in the middle third of the footing depth. One Way Slab Bar Bending Schedule Calculation. 6. 31 of IS456-2000, the span by depth ratio of two way slab is applicable for flat slabs and the values can be (l/d)modified by 0. Now we have to calculate the depth from maximum moment values. Minimum clear cover to reinforcements in slab depends on the durability criteria and this is. Number of Main Bars = Ly / spacing + 1 = (4000/150) + 1 = 27 nos. 4. Spacing Requirements. 1. 15 mm or diameter of bar. Ensure a minimum number of bars in a square column is 4 and in a circular column, 6. 42d. Spacing of bar = area of a bar * width of strip / area of reinforcement required = 78. Distribution bars of diameter 12 mm and center to center spacing 150 mmm. Nos of Bars =. a) Slab depth does not exceed 250mm when the steel grade is 250. 1000 1500 2000. 002 times the gross cross-sectional area of the footing. Distribution Bar = 12 Number of The Distribution Bar. The main reinforcement of an RC slab consists of 10 mm bars at 10 cm spacing. 1 or the bottom bars required by 8. 1905. d = Effective depth. is lapped with a lower bar of 20mm dia. 15%of gross cross-sectional area if plain bars are used and 0. ? 1. length of dowel bar and a maximum joint opening of 0. 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. unless otherwise noted, all slabs on grade are to be reinforced with 10mm bars at 400mm o. The previous code that allowed up to Grade 520 was changed to Grade 550, and related regulations were modified. 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. Number of Main Bars = Ly / spacing + 1 = (4000/150) + 1 = 27 nos. 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. The complete calculation for one way slab is explained in the below steps. Minimum number of reinforcing bars. 5. No Of Bars Required For Cutting Distribution Bars. 1—Early-age concrete material strength development 4. The distribution bars are arranged to retain the mesh in perfect place and sustain the center to center c/c, bars. . The code requires this value to be the minimum of these three values. 3. Refer to Section 5. Suppose we have a one way slab,which having a length 5 m or width 2 m (clear span). 751. Sub-slab details (i. 9 Factored loads Factored dead load = 3. 5. 4, Chapter 10 ct = distance from the interior face of the column to the slab edge measured parallel to c1. The distribution bars are arranged to retain the mesh in exact location and keep the center to center c/c, bars spacing among main bars. slab to provide shear resistance. 1 of IS 456), the maximum spacing is the lesser of 3d and 300 mm i. 4. Spacing =150mm. 26. f d n §· ¨¸ ¨¸ ©¹ ©¹ Since the required nominal moment from Section 1 (M n,reqThe Chinese code “Code for composite slabs design and construction” (CECS273:2010) states [34] that steel-bars truss can work with concrete as upper and lower bearing reinforcement in concrete, but without considering the role of steel-bars truss as a whole and bottom PSS, the bearing capacity of SBTS is calculated according to ordinary. 304. 7. 300mm. The maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. 3 introduces a new requirement for barBridge Deck Slab Design Example as per IRC Indian Codes, Deck Slab Bridge Design are described step by step by Using Limit State Method. where is the radius of the wheel load distribution in cm and is the slab thickness in cm. The Indian Standard (IS) code for the preparation of steel bar bending schedules is IS 2502:1959. The code makes it explicit that the diameters of the skin bars are not involved in determining the spacing of this reinforcement. 2 times effective depth b. 3. 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. Fig. Design a one-way slab having a simple span of 3 m. 3. 1. 347. 9) Check for shear ( using Table 19 of code IS 456:2000). So No, of 8 mm Steel bar = 3. C. 2. 6H, and 0. 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. Q) Calculate the quantity and weight of steel rod in a one-way slab having length 6 m, width 2. critical section of the slab is just outside the outside edge of the beam supporting the slab. The minimum reinforcement spacing is based on maximum size of aggregates, so that concrete can be placed and compacted properly. d = Effective depth. For. From clause 26. ratio of flexural stiffuess. 3. 300 Area of bars Φ12, a=π62 = 113. So, we need to calculate the value of ‘D’. This method is applicable to straight and right (i. with a banded tendon distribution is achieved without this. Loads which consist of any on e of the following: moving live loads exceeding a. 7. Fig. 5 bar is permitted to be located at either the top of the slab or bottom of the footing. Every alternate bar is cranked up to 0. It is a useful reference for engineers, planners and contractors involved in bridge construction. , and if the lap length is taken as 50d, then. Total length of Foundation Distribution bar =No’s of bar x cutting length. 6—Factors affecting the construction load distribution 3. Considering M20 grade of concrete and Fe 500 steel of diameter of 10 mm. ”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. 2. stationary live loads less than 400 po unds per square foot. Number of Distribution Bars = Lx / spacing + 1 = 3000/150 + 1 = 21 nos. MOM-X – Longitudinal moment, corresponding to which LONG. BS EN 1992-1-1 Annex 1 1. The term "standard hook" as used in this Code shall mean one of the following: (a) 180o.