How is grade slab calculated?

How is grade slab calculated?


  1. Determine how thick you want the concrete.
  2. Measure the length and width that you’d like to cover.
  3. Multiply the length by the width to determine square footage.
  4. Convert the thickness from inches to feet.
  5. Multiply the thickness in feet by the square footage to determine cubic feet.

How thick should slab on grade be?

For example, according to the California Building Code, if you want to make a concrete slab with direct support on the ground, you should ensure it is at least 3.5 inches thick. However, most residential and commercial properties usually have a concrete slab at least six inches thick.

How do you calculate slab on grade rebar?

For the best way to estimate the quantity of rebar in slab, one has to:

  1. find out the total length of rebar.
  2. multiply that length of rebar by the weight per length associated with the size of rebar that is used.

What is the grade slab?

Slabs which are directly laid on the earth, to support walls and other structural elements are called as Slab on grade or Grade Slabs. This type of slab is casted directly on ground level. Grade slab itself acts as a foundation for the building which does not require further footings.

How do you calculate slab load capacity?


  1. Loads on the RCC Slab. Self-weight= concrete unit weight * Volume of concrete. = 24 * 0.1= 2.4 KN/m2
  2. Loads on the Beam. Self-weight= concrete unit weight* beam width*beam height. =24 * 0.28*0.25= 1.68 KN/m.
  3. Compute Applied Moment. Assume partial fixity of columns.
  4. Geometry of the Original Section.

How strong is 3 inches of concrete?

So, the “4,000 PSI” rating is for the standard 4-inch thickness of a residential concrete slab. This means that a 3-inch slab will be slightly weaker, while a 5-inch slab will be slightly stronger, in terms of compressive strength. Tensile strength is a bit harder to measure.

What is a slab-on-grade?

A slab-on-grade foundation—also known as a floating slab foundation—is a structural engineering practice in which the concrete slab that will serve as the foundation for a building or other structure is formed from a mold that is set into the ground.

How is slab reinforcement calculated?

Steps to calculate the Reinforcement required for Slab:-

  1. Deduct the cover for finding length of bar.
  2. Evaluate the length of the distribution bar.
  3. Calculate the Value of ‘D’ (Depth of slab- Top cover- Bottom cover)
  4. Find out the No. of Bars.
  5. Compute the Total wt of steel required for slab reinforcement.

How do you calculate reinforcement in slab?

The quantity is done in two steps.

  1. (Calculation of Bars No’s) First, calculate the number of bars required (main and distribution both). FORMULA = (Total length – Clear cover)/center to center spacing + 1. Main bar = (5000 – (25+25))/100 + 1.
  2. (Cutting length) MAIN BAR: FORMULA = (L) + (2 x Ld) + (1 x 0.42D) – (2 x 1d)

How is two-way slab calculated?

If the longer span of the slab is ly and the shorter span is lx, then for a two-way slab, ly/lx is less than 2. If the ratio is greater than 2, it is identified as a one-way slab. The two-way slabs distribute the loads in both directions. Hence, the reinforcement is provided along shorter and longer sides of the slabs.

What is difference between slab and slab on grade?

In summary: Slab on grade used in areas where ground does not freeze. The edges of the slab-on-grade are thicker than the interior of the slab. The slab-on-grade is monolithic (poured all at one time).

How do you calculate slab thickness?

Standards like ACI 318 have specified the minimum thickness of the slab based on the span of the slab.

  1. Simply Supported Slab = Span / 20.
  2. One End Continuous Slab = Span / 24.
  3. Both End Continuous Slab = Span / 28.
  4. Cantiliver = Span / 10.