Steel Reinforcement Tables
Table of Contents
Reinforcement Tables
Reinforcing bars are generally designated as B6,B8,B10,B12,B16,B20,B25,B32 and B40, although B40 is not generally used. This is generally due to procurement and that the bending radius of the bar and required lap/anchorage length can make it impractical in designs.
The bars are not smooth but have raised ribs on the surface which improves the bond between the concrete and steel. The characteristic strength for high yield reinforcement is \(f_{yk} = 500N/mm^2\)
This article summarizes the weights and areas of steel reinforcement tables, that can easily be used as a resource in design applications.
Table 1: Weight of Steel Reinforcement Tables (kg/m)
Table 2: Area of Steel Reinforcement Tables (mm2/m)
Table 3: Reinforcement Area (mm2/m) for various bar spacing
Table 4: Wire Fabric (Reinforcement Mesh)
Sectional areas for varying mesh types
Table 5: Minimum and Maximum percentages of reinforcement
Elements containing less reinforcement than As minimum should be considered un-reinforced.
Example 1: Calculate the reinforcement bar area using Table 1
A concrete slab has 5 x 12 diameter steel reinforcement bars every 1000mm width. What is the total reinforcement bar area?
Using the tables above, we can see that the total bar area for 5 x B12 diameter bars are 565mm2/m.
Example 2: Calculate the reinforcement bar area Table 2
A concrete slab has 16mm diameter bars at 150mm centers. What is the total reinforcement bar area?
Using the tables above, we can see that the total bar area for B16 diameter bars at 150mm spacing is 1340mm2/m.
Example 3: Calculate the reinforcement bar area Table 1 and 2
A concrete slab requires a minimum of 1500mm2/m of tension steel in the bottom of the concrete (assume minimum cover of 30mm). What steel bars and at what spacings should they specified at?
Using the tables, we can specify 5 x B20 bars over the span of a meter (200mm spacing), which gives an area of 1571mm, or
B16 @ 125mm centers, which gives an area of 1610 mm2/m.
Note- there are many types of combinations that we can specify, but we should consider the practicality when choosing sizes and spacing.
We need to consider if we can place fixings in the concrete after the concrete has set (i.e, if the reinforcement is spaced too close, there will be clashes with bolts and fixings in the slab).