The rebar weight 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.
INSTRUCTIONS: Choose units and enter the following:
Weight of Rebar: The calculator returns the total weight of the rebar in pounds. However, this can be automatically converted into other weight units (e.g. kilograms or tons) via the pull-down menu. If OC set to length, thes) is return in feet, which can be automatically converted to other length units (e.g. meters or yards) via the pull-down menu. See the for more concrete and rebar functions and features. See for a YouTube video on the use of this calculator.
Rebar is short for "Reinforcement Bars". Rebar is often used inside concrete for added strength, including use in common slabs. This formula provides a length and weigh rebar calculation that is useful in understanding the additional load of the slab added by the rebar steel. It is also useful for calculating the weight of rebar for rebar expense and when considering transport. Steel is dense and heavy. Most vehicles would be considerably overloaded in weight of rebar long before their potential volume is full, which poses a significant safety issue. In the U.S., most pickup trucks are rated at a half or three quarters ton load rating. This rating indicates the safe weight of a load that can be carried. The rebar weight formula can help determine how many trips are required to transport the load of reinforcement steel safely.
The rebar weight algorithm calculates the weight of reinforcement steel bars in a concrete slab. The algorithm calculates the area of the slab, and calculates the length of rebar needed for a rectangular grid within the slab. The grid is specified by the inset from the edge of the slab and the nominal separation between horizontal and vertical rows of rebar (onCenter - see diagram). Once the algorithm calculates the length of rebar, the length is used with the user specified rebar size, and density constants from the vCalc library to calculate the total weight of the reinforcement steel bars.
The user specified parameters are:
The calculation determines the need for an extra rebar using an internal tolerance for for a spacing fraction that exceeds the tolerance with a default of 1".
Rebar lapping is required when the dimensions of your slab or wall exceed the length of a single piece (stick) of rebar. In this case, it is required to lap and to create the added length. There are a few considerations. First, the length of the rebar lap is specified as a factor (LF) times the diameter of the rebar which is different for each size of rebar. Lapping factors of 40 and 60 are common, but the engineering lapping factor specification should always be applied. See the following YouTube videos to better understand rebar lap:
Second, the typical lengths of pre-cut rebar 20', 40' and 60' in the United States.