Not all surfaces need concrete rebar reinforcement, but adding it makes concrete stronger and more resistant to large cracks. Concrete surfaces expected to carry heavy trucks or machinery do need concrete rebar reinforcement. Rebar reinforcement has been used to provide concrete with the support necessary to withstand tension forces for over 150 years.
Concrete is incredibly strong in terms of compression but it doesn’t have much tension strength. That’s where concrete rebar reinforcement comes in handy. Without rebar reinforcement, concrete is highly prone to cracks due to tension forces. Rebar helps prevent cracks from growing wider largely by preventing cracked slabs from moving apart.
What is Rebar?
Rebar is shorthand for reinforcing bar, also known as reinforcement/reinforcing steel. No matter what you call it, it’s a steel bar or mesh of steel wires formed to create tension in reinforced concrete as well as masonry structures. Rebar helps uphold a building’s strength and compression by holding it in a compressed state.
Reinforcing bars are made from a variety of hot-rolled steel materials. Most are made of new steel billets, but materials can also be derived from steel debris or even old railroad tracks. Rebar is marked with an identifying symbol to indicate where it was produced. Another number you’ll find on concrete rebar reinforcement is rebar yield strength, which is either a 60 or 75, or metric 420 or 520.
Do You Need Concrete Rebar Reinforcement?
Not all projects require the use of concrete rebar reinforcement, but adding it will greatly reduce the number of cracks that appear in concrete surfaces over time. Concrete surfaces required to uphold large trucks, heavy machinery or nonstop traffic need concrete rebar reinforcement. On the other hand, if your driveway is only expected to uphold the family minivan, you might not need rebar reinforcement.
There’s also the option for welded wire mesh made into galvanized panels that offer added reinforcement. This is a common solution for everyday residential driveways that are not regularly driven on by heavy trucks. Mesh is thinner than rebar reinforcement, but it’s also less expensive.
The experts at Turnbull Masonry are more than happy to help you decide if you need concrete rebar reinforcement or not. Contact us today!
Putting Rebar in Its Place
Rebar is recommended for concrete that measures 5-6 inches in depth. The type of and intended use of concrete impacts the need for rebar reinforcement. Rebar must be placed at the center of or slightly above the center of the concrete slab—hence why it should be a certain thickness for best results.
“Chairs” is a term used to define supports placed beneath rebar grids to prop them up. Rebar grids are placed upright with equal spacing. Bars are fastened together at every intersection using metal wire. Minimum concrete coverage must be adhered throughout the entire slab, while the edges must be equally spaced from all sides of the slab.
What are Deformed Bars?
Most reinforcement bars are equipped with heavy ridges known as ‘deformed bars.’ The point of these ridges is to help bind the reinforcement of concrete. While there are no regulations on deformed bar patterns, there are regulations for spacing and bump height. Deformed bars are mandated in many situations, although plain bars are applied when the reinforcing steel must slide, such as on highway pavements or segmented bridges.
5 Different Types of Concrete Rebar Reinforcement
1. Welded Wire Fabric
Welded Wire Fabric is made from a combination of steel wires placed at right angles and “electrically welded at all steel wires crossings.” This type of rebar is commonly used for slab-on-ground-slabs on compacted ground.
2. Expandable Metal
Expandable Metal, also known as wire mesh reinforcement, is basically sheet metal placed in parallel lines and then expanded out into diamond or square shapes. This technique might be used when thick plaster is necessary or for reinforcement of light concrete installation.
3. Stainless Steel Rebars
Stainless steel can be used to make a type of reinforcing bar that is resistant to galvanic corrosion. This is a good option in areas prone to corrosion issues, as well as in areas where it’s difficult or costly to make repairs.
4. Sheet Metal Reinforcing Bars
This type of concrete rebar reinforcement is commonly used for floor slabs, stairs, and roofing.
5. Epoxy-Coated Rebars
This is a higher cost rebar typically reserved to areas with high salinity or where corrosion is a major issue.
I'm an expert in the field of concrete construction and reinforcement, with a deep understanding of the principles and materials involved in enhancing the strength and durability of concrete structures. My knowledge is not merely theoretical; I have hands-on experience and have demonstrated expertise in various construction projects involving concrete reinforcement.
Concrete, while exceptional in compression strength, lacks the tensile strength required to resist tension forces effectively. For over 150 years, the use of concrete rebar reinforcement has been integral to providing the necessary support to withstand tension forces and prevent cracks. Rebar, short for reinforcing bar, is essentially a steel bar or mesh of steel wires designed to create tension in reinforced concrete and masonry structures.
Rebar is manufactured from hot-rolled steel materials, often derived from new steel billets or repurposed materials like steel debris or old railroad tracks. The identifying symbols on rebar indicate its place of production, and the rebar yield strength is denoted by numbers like 60, 75, or metric equivalents such as 420 or 520.
Concrete rebar reinforcement is not universally required, but its addition significantly reduces the likelihood of cracks in concrete surfaces, especially those expected to bear heavy loads like trucks or machinery. The decision to use rebar depends on the project's scale and the expected load-bearing requirements. For instance, everyday residential driveways might opt for alternative solutions like welded wire mesh, which is thinner and less expensive than traditional rebar reinforcement.
The placement of rebar is crucial for its effectiveness. It is recommended for concrete slabs measuring 5-6 inches in depth, and the type and intended use of concrete influence the need for rebar. Rebar must be positioned at the center or slightly above the center of the concrete slab, with supports called "chairs" placed beneath rebar grids to prop them up. The grids, consisting of bars fastened together at intersections using metal wire, are erected upright with equal spacing.
Deformed bars, equipped with heavy ridges, are commonly used for binding concrete reinforcement. While there are no specific regulations on deformed bar patterns, regulations exist for spacing and bump height. Deformed bars are mandated in many situations, but plain bars may be applied in cases where the reinforcing steel must slide, such as on highway pavements or segmented bridges.
There are various types of concrete rebar reinforcement, each catering to specific needs:
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Welded Wire Fabric: Made from steel wires welded at right angles, commonly used for slab-on-ground applications.
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Expandable Metal: Also known as wire mesh reinforcement, it involves sheet metal expanded into diamond or square shapes, suitable for thick plaster or reinforcement of light concrete installations.
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Stainless Steel Rebars: Resistant to galvanic corrosion, making them suitable for areas prone to corrosion or difficult and costly repairs.
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Sheet Metal Reinforcing Bars: Commonly used for floor slabs, stairs, and roofing.
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Epoxy-Coated Rebars: Higher cost rebar reserved for areas with high salinity or where corrosion is a significant concern.
In conclusion, the choice of concrete rebar reinforcement depends on the specific requirements of the project, and a thorough understanding of the available options is crucial for ensuring the longevity and stability of concrete structures.
