Reinforced concrete was introduced in the 19th century, and it revolutionized the construction industry. Since then, reinforced concrete has become one of the most common building materials in the world.
But what exactly is reinforced concrete? When should you use it, and how much stronger is it compared to regular concrete?
What is Reinforced Concrete?
Reinforced concrete is a type of concrete in which steel is embedded in a way that allows the two materials to work together to resist forces. For example, steel rods, mesh or bars work to absorb the shear, tensile and compressive stresses in a concrete structure.
Typically, steel rods (or rebar) are used to passively reinforce the concrete. Rebar is placed in the concrete before it sets.
Reinforced concrete can be either cast-in-place or precast.
One of the first examples of reinforced concrete construction is the Leaning Tower of Nevyansk in Russia. The structure was built in the 1720s under the orders of Akinfiy Demidov. In 1853, François Coignet built a four-story, iron-reinforced concrete home in Paris. These are just two of the earliest examples of reinforced concrete, and several major projects followed over the next few centuries.
When Should You Use Reinforced Concrete?
On its own, concrete is weak against shear and tensile stress from earthquakes, wind and vibrations. Together, concrete and steel allow the member to withstand stresses over long spans.
Generally, reinforced concrete is used in large-scale construction, such as:
- Tall buildings
Most commonly, it’s used in residential construction for foundations and footings of homes. Many other components of structures are also built with reinforced concrete, including:
Concrete doesn’t always have to be reinforced. However, if your concrete is going to be more than 5 inches in depth, it’s best to add rebar to reinforce the structure.
How Can Concrete Be Reinforced?
Reinforced concrete is strong, more durable and ideal for everything from cutting-edge homes and even bridges. Aggregates help reinforce concrete, and these materials may include:
- Glass fiber
- Steel wires
Different types of reinforcement are available, and each type adds in its own strengths and weaknesses.
Types of Reinforced Concrete
While there are multiple types of reinforced concrete, the following are the most popular:
Glass Fiber Reinforced Concrete (GFRC)
GFRC is ideal for lightweight solutions, such as pouring concrete countertops. You can use GFRC for thin solutions, and the benefit is that this type of reinforced concrete provides:
- Extreme durability
- Applications of 1” or thicker
- High flexural strength
If a builder needs to pour concrete in complex shapes, they can with GFRC because there’s no concern of chipping or cracking. High tensile strength also offers the benefit of secondary reinforcement solutions.
Rebar is a common addition to concrete because it adds tensile durability and strength. One of the key benefits of rebar is it can be used in most poured applications and can meet the different size and shape requirements needed to meet unique construction requirements.
Steel reinforced concrete is the industry standard because it’s one of the most versatile solutions available.
When constructing concrete homes to withstand extreme weather conditions, traditional steel reinforced concrete is the go-to solution.
Pre-Stress Concrete Strand
Pre-stress concrete strand (PC) uses multiwire carbon steel to create compression forces. When using reinforced concrete for pre-cast structures, PC is the ideal choice. You’ll find PC used widely in:
- Commercial buildings
- Parking decks
Cost-effective and strong, one of the main reasons to use PC is because it has a very high strength-to-weight ratio.
Post-tension concrete is common in:
- Commercial flooring
- Concrete slabs
Post-tension concrete is made using rebar steel, but there’s also the addition of steel cables placed in the duct or sleeve to add tension after the curing process. Cables add a tight band around the slab’s perimeter for additional tension.
Round Structural Solutions
When reinforcement is necessary for concrete pouring, it’s often called round structural concrete. You may also find this solution called wire mesh or pool wire, and it’s the ideal solution for spraying.
For example, support necessary for concrete pool lining can be made with pool wire.
When casted pieces are needed, round structural solutions work well. Many builders are beginning to use carbon fiber solutions to create support when pouring concrete countertops and other solutions.
Additionally, carbon fiber is extremely lightweight and resistant to corrosion.
Steel rebar is by far the most common type of reinforced concrete because it is able to meet the needs of most any poured application. In addition, builders can easily manipulate rebar and use it for applications that demand varying dimensions, lengths and grades.
How Much Stronger is Reinforced Concrete?
What makes reinforced concrete so strong? And how much stronger is it than regular concrete?
There are a few characteristics that make reinforced concrete so strong.
- The alkaline nature of the concrete creates a protective film around the steel to help prevent corrosion.
- When the cement paste hardens, it conforms to the steel, allowing stress to be transmitted efficiently between both materials.
- Concrete and steel have a similar coefficient of thermal expansion, so thermal contraction and expansion are less of a concern.
Of course, reinforced concrete is stronger than regular concrete because it can withstand different kinds of stresses that regular concrete cannot.
Reinforced concrete’s tensile strength is about 100 times that of regular concrete.
Without reinforcement, it wouldn’t be possible to build concrete homes. While regular concrete is strong and durable, it’s weak against other stresses that affect homes and structures in general. From walls to foundations, flooring and slabs, reinforced concrete has become one of the most common and popular building materials in the world.