08 x 50 = 4 total cubic yards of concrete for 50 tubes. It is generally accepted that rebar should have minimum 6″ clear cover from all edges, corners, and other forms of reinforcement. Maximum area of longitudinal reinforcement The maximum area of tension and compression reinforcement in reinforced concrete beams is;. 037 to get cubic yards of concrete. Multiply 0. 2 kg. Provide the diameter or cross-sectional dimensions of your concrete column, as well as. Based on this average cost, a 10x10 concrete slab will cost $821, a 20x20 concrete slab will cost $3,284, and a 30x30 concrete slab. Start simply by entering "Add/edit Section" to add the main beam section. Then add 10 percent to allow for spillage and slab depth variations to help determine the concrete cost per yard. Total rebar weight 53. 5 feet. g. Column: 100 kg of normal rebar steel. Making sure to keep the rebar as level as possible, you should place each piece one foot apart. The percentage of reinforcing refers to the cross-sectional area of the steel for a given width of slab divided by the cross-sectional area of the slab area considered. 33_2_0. If your wall is over 40 feet long it will add 2x the amount of overlap required. In climate zones 4 and 5, the code requires certain slabs (below-grade slabs that are less than 12 in. Length of bar = L or W–concrete cover for both. Calculators for structural engineers, construction professionals and steel building specifiers. slab and foundation contractors to help with your footings. 5%. For example, if the area is 10 feet long and 6 feet wide, the square footage is 60 feet. INSTRUCTIONS: Choose units and enter the following: ( L) Length of the slab. 2, two-way slabs are designed based on "column strips" and "middle strips". This allows the de-signer to maintain a constant slab depth without thickening at joints or edges. 5(alternate) and 5. For column = 2. I am looking for information to calculate what is my required dowel rebar size and embedment length to dowel into a reinforced concrete slab? I know ACI has provisions for doweling a concrete column/pedestal into a footing, but I am trying to find something regarding doweling CMU rebar into a concrete slab. ( W) Width of the slab. = 565. Foundation Cost. Dead load, g = (3. Our calculator will instantly calculate the quantity of rebar required. 9 of ACI 318-14 or Section 12. 260X0. Rebar - Slab, Driveway or Patio. ACI 318-05, Section 11. 2. Choose Round Column (or Round Slab) on the calculator. The first step is to determine how much rebar is required to support your foundation. Enter the slab dimensions, desired rebar spacing and the spacing from the edge to quickly find how to lay out the rebar grid. Enter Height 4 ft (or 48 in) Enter Diameter 10 in. Lets take example of RCC Column, where reinforcement. In this section, we will calculate the required reinforced steel rebar using the reference of the Australian Standard. Concrete. Density of Steel Rod = 7850 Kg/m 3. Here are the in-depth steps for columns: Find the dimensions of your columns. 2, see D. Concrete slabs thinner than 4” typically don’t need rebar. This spreadsheet is very useful for making design of reinforced. The average cost of a concrete slab is $8. Therefore, you will need approximately 2. We first obtain the total factored bending moment to be carried out by the slab’s unitary width strip. For example, if the length is 10 feet and the width is 8 feet, the area would be 10 x 8 = 80 square feet. Placement and bar diameter are important to the structural strength of the concrete. INSTRUCTIONS: Choose units and enter the following: (r) Radius of Circular Slab (e. 65 and the thickness of the slab is 6 inches, M = 0. Density of cement = 1440 Kg/m 3. The ratio of the longer span to the shorter span in a two-way slab, known as the span ratio, can vary but is typically around 2:1 in many design scenarios. 014/4 = 0. ACI 318 includes the requirements for design and construction of structural concrete that are necessary to ensure public health and safety. REINFORCEMENT Estimate Calculator. 01942 pounds per linear foot. No. 56. In the following tutorial, we will explore how to model, analyse and design a concrete slab on grade using the SkyCiv software. We typically ask our structural engineer for the weight of rebar is per sf (slabs) or volume of concrete for each mix/use. Note that any portion of your slab or wall on your plans that has additional depth or re-enforcement added to it must be recalculate. Calculate Lap Length in Column Beam & Slab formula. ACI 318-08 Calculator Spreadsheet; Reinforcing Rebar Engineering Data Rebar (short for reinforcing bar ),. The effective compressive strength of a column increases as it is confined by the slab, and the. 2: Repeat and continue to draw complete (closed) shape. Rebar Weights: The table below is based on a 10 % lap and works with any diameter rebar. 74 sq feet 5000/2. Input length, width and depth of the area. The net result is a more accurate and less. 075)kN m2 × 1m = 9. g. Start simply by entering "Add/edit Section" to add the main beam section. Step 4: Place all of the step-up rebar you’ll. Once this is complete, you will need to add the steel reinforcement bars (or similar) by clicking the "Add/Edit Steel Reinforcement. Rebar Development Length Calculator. Supporting the rebar during the concrete pour is. For example, if the percentage is 0. Steps to Calculate Steel Quantity · Enter the Length and Width of your slab in ft in Excel Sheet. Rebar has a Density of 7,841. Click the button to calculate the volume of concrete and man-hours (not including mixing) needed for this job. Reduction or elimination of random cracks. Finally, take a look at the calculation results: grid length = 5. There is a formula to figure the amount of concrete for a slab, floor or patio. Multiply the length (10 ft. However,. Columns that support flat plate slabs and columns that are supported by footings are the most common examples. For multi sided slab, first draw the shape: 1: Hit Clear + Start and enter Side Length of first side to draw, then hit appropriate direction (Arrow) button to draw. calculate the required number of bars for both directions. 2. R – Radius of the slab. All this procedure is totally automated in SkyCiv Reinforced. Standard Data used in this Calculator. Input length, width and depth of the area. The formulas calculate materials needed for rectangular, circular and irregular shaped slabs. Concrete slabs thicker than 4” will often need rebar, especially for heavy-vehicle parking areas. By special permission of the publishers, Co n c re t eproject has two structures, both of them have removal of concrete, class B concrete, and new strip seal expansion devices. The gauge, or diameter, of the rebar is selected based on the purpose and the load-bearing requirements of the structure: For standard residential concrete slabs, #3 (3/8 inch diameter) to #5 (5/8 inch diameter) rebar is typically used. the Android app here: the iPhone app here: The maximum bending moment per meter width of slab, Where, w = total load intensity per square meter of the slab. 01942 lbs/ft. The experimental program was designed to evaluate how flexural performance at service and ultimate limit states are affected by a one-to-one replacement of Grade 60 with CRR bars, a reduction of concrete clear cover, and a reduction in rebarThe use of the rebar bar in construction extends up to the 15 century for masonry structures. 0 + 6. After finding the overall thickness of the slab, compute the volume to determine how many bags of concrete you need for a given slab. ACI 318M-14 Equation 25. 8 kg . Whether you need stock rebar, fabricated rebar, or PJ’s Pre-Assembled Rebar Products, our rebar calculator can help you determine how much weight is in your job. As one cubic yard is equal as 27 cubic feet and weight of 1 cubic foot rebar is around 490 pounds, so wt of rebar per cubic yard = 490 × 27=13232 pounds, regarding this, weight of rebar per cubic yard, generally, it will be 13232 pounds. Concrete calculators that estimate the amount of concrete and rebar you need for footings, concrete walls, concrete stairs, slabs, patios and driveways. The Rebar for an Irregular Shaped Slab calculator estimates the total length and weight of reinforcement bars (rebar) needed for an irregular shaped concrete slab. Rebar, or reinforcing bar, is used in many masonry and concrete projects to reinforce slabs and structures. . Sounds easy, but the trick is to de-t e r mine the amount of beam cam-This calculator uses 35% of balanced rebar area as the steel area for design of slab. A rebar slab calculator is a tool used to determine the quantity and spacing of reinforcing bars (rebars) needed in a concrete slab. rebar strength is in tension, so by adding rebar to BOTTOM of foundation, it counter acts the load of compression. If the slab has hydronic tubing, the minimum R-value of this insulation increases to R-15. If an end-to-end distance between the lap is the least, then the lap should be provided in a staggered manner. Step 1: Determine the dimensions: Measure the length and width of the concrete slab in feet. At the net tensile strain limit of 0. Fire design of cast-in place and post-installed anchors in concrete under fire is covered by EN 1992-4, Annex D, allowing steel- and concrete-related failure modes of anchors to be calculated. The Weight of Rebar in a Slab calculator computes the total weight Concrete Slab with one Rebar Grid mat of reinforcement bars (rebar) needed for a concrete slab based on the dimensions of the slab and the spacing and size of the rebar. 10m= 3m3:- here we have slab of 6 meter length, 5 meters width and 100mm or 4″ thick, so volume of concrete of slab = 6m × 5m × 0. 6. 00 per linear foot for stainless steel rebar. Calculating The Rebar Spacing For A Concrete Slab. How do you calculate rebar spacing? Find the rebar-to-spacing multiplier with the formula M = 0. pre-mix 60 lb bags: $4 – $14 per bag. How much rebar do you need? How to calculate the quantity and size of steel reinforcement in a concrete suspended slab the easy way! Work out loads, then ben. The gauge, or diameter, of the rebar is selected based on the purpose and the load-bearing requirements of the structure: For standard residential concrete slabs, #3 (3/8 inch diameter) to #5 (5/8 inch diameter) rebar is typically used. of Main bars = 20 + 1 = 21 Nos. No. For direct tension, Lap length = 2 x L x d or 30 x d (The greater value among the two values calculated is taken. 4. There are four types of two-way slabs. 25 * 12. This is usually taken to be 75% of the steel yield stress. 78. To truly reinforce concrete, the percentage. 87 (round up to 13) Add one rebar to your result: 13 + 1 = 14. The formula for the weight of a slab used in this calculator is: Wt = L•W•D•mD. e ve r y type of concrete construction that will be encoun-t e r ed on residential, commercial and industrial build-ing including form s , re i n f o r cing steel, and concre t e placement. Convert the weight of the bag to the volume. Multiply the measurements together to calculate the square footage of the area. Using the Plate Design. ACI 318M-14 Equation 25. Report Application Issues or Provide Customer Feedback. 125 - 0. slab at 12” on center? Table shows: . xls", so called to reflect the use of the ACI 318-05 Code. Example Calculation: Suppose you have a concrete slab with dimensions of 10 feet by. . First, find the area of the slab. Inputs can be either imperial or metric with results shown to. If your wall is over 40 feet long it will add 2x the amount of overlap required. The weight of a concrete slab can be estimated by computing the volume of the slab and multiplying the volume (V) by the density of the concrete. After finding the overall thickness of the slab, compute the volume to determine how many bags of concrete you need for a given slab. Placing tubing deeper in the slab means, simply-put, that more heat will transfer into the slab and ultimately into the soil below than will be transferred up to the top of the slab and into the occupied space. epoxy-coated reinforcing steel was compared to deck slab specimens where Grade 60 is replaced with CRR bars. Online Concrete Slab on Grade Analysis Calculator For Slab Subjected to Interior Concentrated Post or Wheel Loading Assuming Slab is Reinforced for Shrinkage and Temperature Only. Generally, the minimum amount of rebar recommended by the American Concrete Institute (ACI) is at least one vertical bar per cubic yard of concrete and two horizontal bars, either laid flat or tied together with wire. Hand calculation according to AS3600 Standard. The Area of a Concrete Slab calculator computes the surface area of a rectangular slab. (feet + inches) Enter the width. With consideration of the combined work of slabs interconnected by reinforcement and absorbing the wave uplife pressure the thickness of the slabs is less than in the calculation for the one most loaded slab (36 and 45 cm),. Now, look up the weight of your rebar. 4. The national average cost of a concrete slab for a garage is $6. To calculate concrete for slabs, add ¼ of an inch to the slab thickness, assuming that the job is evenly graded to the proper depth. Column strip includes beams if any. (a) A flat plate which is a two-way slab supported on a column grid without the use of beams. The flange of a T-section is formed by the effective width of the slab, as defined in Section 8. Ridges in the surface of the rebar allow the concrete to adhere to it and create one solid structure. Concrete Slabs Calculator. Volume of Concrete in slabs in cubic yards and meters. 2. Standard Data Taken The density of Steel Rod = 7850 Kg/m 3 1 meter = 3. 2 CY for Site B when taken to the tenth of a cubic yard (0. 56% and Equation b) for λ= 1 and ρ w > 1. coverage = 5′ × 50′. Calculate the main reinforcement per metre width; For M15 concrete, lever arm = 0. Concrete is very strong under compressive stress and shear stress, but it performs poorly under tensile strength. 2). Click the button to calculate the volume of concrete and man-hours (not including mixing) needed for this job. Enhancement of the strength of the. 45 cubic feet. coverage = 250 sq ft. Square Column: $$ Volumeleft(ft^{3} ight) = Height * Length * Width $$. The appropriate rebar size depends on the project, with #3 and #4 being common choices. As we know that Density = Mass/volume. The PT Calculator is ideal for owners, developers, contractors, architects, and engineers who need to quickly estimate quantities and concrete sizes. The only formula you need to remember for the entire calculation is . Fa b r ic may also be supported at the center of the slab, or it may be installed in two flat layers with the top layer (nega-t i v e steel) extending on either side of the support for one-quarter of theSteps to Calculate Steel Quantity · Enter the Length and Width of your slab in ft in Excel Sheet. Example Calculation: Suppose you have a concrete slab with dimensions of 10 feet by 10 feet, and you plan to use 0. The size and placement of rebar based on the slab length, width, and thickness should be identified. Calculate the number of rebar lengths needed for concrete reinforcement. Mark your project plans with a highlighter wherever the psi amount you calculated in Step 3 is found. 395 kg/m. On average, a 60-pound bag of concrete covers about 0. Generally, it is recommended to use at least two layers for a slab and that the rebar should be placed 6 inches apart for maximum strength. Spread 3-4 inches of gravel aggregate within the formwork. 1. "REBARS (318-05). The average cost to install a concrete slab is $6 – $20 per square foot. h – Distance between the reinforcement. (D) Depth of Slab (e. 3—Steel fiber reinforcement Chapter 12—Structural slabs-on-ground supporting building code loads, p. #3 rebar is ⅜” in diameter, #4 is ½” in diameter, and so on. For the design of slabs-on-ground with fiber reinforcement, Chapter 11 in the American Concrete Institute’s (ACI) 360R guide provides detailed information and calculations. An older reinforced concrete design calculator that computes required steel area for T-beams and 1-way slabs can be found here. A concrete slab of uniform thick-ness can be placed by positioning the screeds at the high and low points of the cambered beam. Result. I'm casting a 4m long triangular-profile reinforced gravity retaining wall against soil movement due to a 1 metre jump in ground level. 5% of concrete volume, weight of steel required will be: =196. Rebar: Concrete Block: Formula: 1. g. Length of bar = L or W–concrete cover for both. ls = (0. Take the value of diameter in terms of millimeter and length in terms of meters. FIrst, find number of rods required for main reinforcement and distribution. They seem to have that. Mass / Volume Conversion. L = √(R 2 – h 2) x 2 where. The SkyCiv slab and wall design module also has the capabilities for reinforcement optimization and checking based on different criteria, including concrete cover, rebar orientation, rebar spacing, member type, and others. The purpose of footings is to support the foundation and prevent settling. For compatibility with older ACI codes, Ψr is taken as 1. 1 m)Rebar Grid Calculator. per square foot without rebar, but you’ll need “control joints” or the slab will crack. Concrete calculators that estimate the amount of concrete and rebar you need for footings, concrete walls, concrete stairs, slabs, patios and driveways. The length of anchorage rebar depends primarily on the type of structure and the size of the rebar being used. If you want to combine rods of two diameters, there would. For example, if a 6-inch-thick slab is used with #3 rebar at 18 inches on center, the percentage of steel for a 12-inch width would be: For enough reinforcing to accomplish. 2. Less concrete, i. It requires careful attention to detail and an understanding of the various. Where; A c is the area of the cross. of Main bars = (Width of Slab/Spacing) + 1. 84 m; grid. Note that the size extra for #3 bars is $4. . The volume is simply the area (A = L*W) times the depth (D). Thickness (inches) Result: Cubic Yard =. 2. 058 percent, which is only enough for crack containment. ) and divide it by 27 (the number of cubic feet in a cubic yard). If needed, add more gravel and compact until you have a 4-inch base. (feet + inches) Enter the grid spacing. (a) A flat plate which is a two-way slab supported on a column grid without the use of beams. 4. Divide the area number calculated in Step 3 by 5, as wire mesh in most commonly. 2. The Rebar Calculator contains equations and data used in working with reinforcement bars (rebar) in concrete slabs. 2. b. It is anticipated that ACI 318–19 will be referenced in the 2021 IBC. Specify the spacings: rebar-rebar spacing = 40 cm, edge-grid spacing = 8 cm. It is used mostly in a combination of these two in concrete slabs. This will mean that the horizontal rebar may be higher to account for the hoop stresses coming out of the page but this is much more efficient than using the. The maximum bending moment per meter width of slab, Where, w = total load intensity per square meter of the slab. Concrete Calculator Efficiently calculate the weight of rebar for your construction projects with our handy rebar weight calculator. The Rebar in a Circular Shaped Slab calculator estimates the total length and weight of reinforcement bars (rebar) needed for a circular shaped concrete slab. Specify the spacings: rebar-rebar spacing = 40 cm, edge-grid spacing = 8 cm. (150 to 250 mm). Convert Cubic Feet to Cubic Yards and Metres. This is a non-destructive probing method. So you have to divide 320 by 4, which equals 80. 2-inch slab; 2-inch chairs for a 4-inch slab; 21⁄ 2- i n c h chairs for a 41⁄ 2-inch slab and 3-inch chairs for a 5-inch slab. Slabs, Square Footings & Walls. When calculating V c, Equation a) for λ= 1 and a longitudinal reinforcement ratio ρ w < 1. No nreinforced slab. Steps to calculate weight of concrete slab in following:-. 360R-44 12. How much rebar do you need? How to calculate the quantity and size of steel reinforcement in a concrete suspended slab the easy way! Work out loads, then ben. This way, the concrete doesn’t receive as much stress . This way, the concrete doesn’t receive as much stress . Step 3: Determine the thickness: Measure. 72 percent. 5 kN/m2 (153 kg/m2) in domestic buildings to approximately 1 0 kN/m2 (1053 kg/m2) in heavy industrial areas. 25L 2, whichever is less. 5 inches into the formula-. Inches. Cut your frame to size and use nails or screws to secure your frame together. In this article, a method is proposed for calculating the reinforcement of concrete ceiling slabs with carbon composite materials based on the finite element model in the computer program SCAD. The weight of a concrete slab can be estimated by computing the volume of the slab and multiplying the volume (V) by the density of the concrete. 28084 feet. If you prefer to calculate the number of bags of concrete needed, you can use the weight of the bags as a reference. ) by the depth (. for more FREE video tutorials covering Concrete Structural DesignThe objective of this video is to determine the area of bottom reinforc. 08 cubic yards for one concrete tube. 3. 40 to $1. Calculate Rebar Quantity From Total Slab Area and Perimeter. In simple, it is a concrete block provided to create the cover between the reinforcement bar and the concrete surface. 38 2 min 1 0. 26897 kg. To calculate Total Area of a multi sided slab, first divide the shape into rectangles or squares. The Rebar in a Circular Shaped Slab calculator estimates the total length and weight of reinforcement bars (rebar) needed for a circular shaped concrete slab. REINFORCEMENT. Added 54% extra mortar to convert wet volume into dry volume. The weight of a concrete slab can be estimated by computing the volume of the slab and multiplying the volume (V) by the density of the concrete. coverage = 250 sq ft. Just plug in the numbers, make sure you choose meters, and hit calculate. So, Mass = Density X Volume. ls = (0. As the slab length increases, the contact area with the base material increases, which increases the total resisting frictional force, resulting in higher tensile stresses as the slab contracts and/or loses moisture. Step 1. This is achieved through techniques such as spraying concrete slabs with compounds that create a film over the concrete that retains water, as well as ponding, where concrete is submerged in water and wrapped in plastic. 4. The compression development length is calculated using Section 25. cracked section transformed to concrete, and effective moment of inertia for T-beams, rectangular beams, or slabs, in accordance with Section 9. Fa b r ic may also be supported at the center of the slab, or it may be installed in two flat layers with the top layer (nega-t i v e steel) extending on either side of the support for one-quarter of theFibre-reinforced polymer (FRP) rebars are being increasingly used to reinforce concrete structures that require long-term resistance to a corrosive environment. Note that this calculation is the volume of your tubes only and does not account for any overflow or loss. The Rebar and Concrete in a Slab calculator computes the total length and weight of rebar and the volume of concrete needed for a slab. The Weight of a Slab with Rebar Calculator computes the weight of rebar in the rectangular slab, and removes the weight of the displaced concrete to provide the best estimate. Similar comparisons could be made for other size s . The calculator will automatically estimate the number of cubic yards of concrete that will be required. As such, I would do one of two things: 1) Effectively lap the rebar with the rebar in the elements above and below. Stretch a string between two screws installed at the edge of both ends of the form boards. a car weight about 5000lb. Concrete slabs on grade are a very common type of concrete construction. The proposed method of calculating reinforced-concrete slabs of slope protection for wave loads is simple and sufficiently accurate. The user must enter the strengths of the concrete and the reinforcement, the unit weight of concrete, strength reduction factor for lightweight concrete, beam dimensions and slab. Where ‘D’ and ‘L’ are the diameter and the length of the rebar respectively. The Rebar for an Irregular Shaped Slab calculator estimates the total length and weight of reinforcement bars (rebar) needed for an irregular shaped concrete slab. Step 3: Determine the Amount of Rebar Required for the Foundation Walls. The first step is to determine how much rebar is required to support your foundation. Now, calculating the quantity of steel = total volume of concrete x density of steel x 0. ( RL) Length of the pre-cut rebar sticks being used to. 4. Factors such as slab size, thickness, reinforcements, and type of finish can affect the overall cost. Number of Distribution Bars = Lx / spacing + 1 = 3000/150 + 1 = 21 nos. Quantity Estimate for Reinforcement in Kg: Quantity Estimation of Reinforcement in Kg. Structural concrete. They are typically made of concrete with rebar reinforcement that has been poured into an excavated trench. 5. · Enter the Thickness of the slab in mm only. 72 percent. Enjoy the Rebar Calculator for Slab. 1) Development of the bar ensures that the rebar won't pull out from the concrete due to a bond failure. For example, if the area is 10 feet long and 6 feet wide, the square footage is 60 feet. Conversion. 6 kg/m³. The Rebar Calculator also has concrete functions to help you compute: Surface Areas of slabs in square feet, yards and meters. The PT Calculator can be used for the following building types: Podium slab with 3 levels of wood construction (4 levels of wood with roof) Podium slab with 4 levels of wood construction (5 levels. The Concrete Weight formula computes the weight of a volume (V) of concrete. Calculate the volume of cubic yards needed to fill in a square or rectangular slab pour for flooring, walls & similar structures. Concrete is very strong under compressive stress and shear stress, but it performs poorly under tensile strength. Weight of one m of rebar is 0. Sq. or ACI 318-11 Section 12. Concrete Slabs Calculator. Determine the Pad's Area. 04A c —- (3). You will need 158. utilizing FRC include ground supported slabs, composite metal deck, pile supported slabs, mat slabs, pavements, bridge decks, tunnel segments, shotcrete, and various precast applications. 85Vc > Vu. This process is called lapping, and the. Call this value "L2. Re-Bar Calculator for a Slab using Custom Cut Lengths. 4 = 188. Fill in the price and single rebar length that you will buy at your supplier: rebar price = €2/m single rebar length = 6 m. Rebar is typically calculated at a rate of 1 for every 8 inches of footing width. the Android app here: the iPhone app here: calculator offers you a choice between five different types of concrete. With our rebar calculator, you can eliminate guesswork and avoid costly mistakes. Advertise Here. 65 and the thickness of the slab is 6 inches, M = 0. The exact distance from the reinforced concrete slab’s edge to the rebar should depend on the specific application, size, and thickness of the slab. Rebar and Slab Calculators: Find how much concrete weighs by entering the. Required thickness of concrete slabs. Where you are pouring the concrete will be your slab. " There is also a Settings button so. g. A s,max = 0. **Unit weight in kg/m is calculated using the formula = D2/162 For 8mm bar = 8 2 /162 = 64/162 = 0. For example, let’s find the number of 5′ x 50′ rolls of mesh required to reinforce a slab that is 25′ by 25′. You’ll find that #3, #4, and #5 size rebar is most commonly found in home reno stores and used in footings for homes and other domestic structures. Calculate how much rebar you need to reinforce a concrete slab. Retaining Walls: The most commonly used rebars in retaining walls are #3, #4 and #5. 005, which is equivalent to a maximum reinforcement ratio of 0. It’s because of non-contact lapping has a full surface area to transfer force to the concrete. g. Note that this calculator does not account for rebar and gravel that may be part of your project. 6m × 5m × 0. With our rebar calculator, you can eliminate. Thickness: Thicker slabs require a higher volume of concrete. Generally, as a general rule for standard-sized residential slabs, 3 to 4 inches should be a sufficient distance between the rebar and the edge of the slab. 2.