What is rebar?
Rebar, often referred to as reinforcement steel or reinforcement bar is used primarily to improvise and enhance the structural strength of concrete. The main advantage of using rebar for the enhancement of concrete is that both rebar and concrete have the same coefficient of thermal expansion. Hence, the two will expand at the same rates.
Given the same rate of thermal expansion paves the way to the main question: Can we weld rebar? Well, let us find out!
Can we weld rebar?
There come a variety of rebars of different sizes and grades out of which some can be welded, while the others cannot. The following are the two types of classifications of rebar:
The structural welding code AWS D1.4 specifies that rebar which is low-alloy mild steel is completely weldable. It has a suitable steel to carbon ratio that makes it a suitable choice for welding. Once enforced with concrete, weldable rebar becomes capable of handling immense load.
Non weld-able rebar
In this type of rebar, the carbon content is quite high, which makes it unsuitable for welding. A high carbon content makes it brittle, and thus, it will shatter upon being welded.
How is rebar welded?
Rebar welding is governed by certain standards so that the best output is achieved. When rebar welding is carried out with 100% efficiency, it offers a strong structural connection that is often known for its rigidity. Thus, it enhances the strength of concrete.
Another myth that most people believe is that welding rebar is a complicated process. However, if proper welding processes, practices, and guidelines are adhered to, welding rebar is an easy task.
Some of the protocols governing the process of rebar welding include:
Selection of the right rebar
Based on the type of rebar chosen, it is important to determine if pre-heating of rebar is necessary or not.
Selection of the right welding wire or rod.
Determination of the criterion to select the perfect weld, metal preparation, and placement.
Methods used in welding rebar
Rebar welding is a simple process and has a few different ways in which it can be done. Here are the three most popular methods of rebar welding:
Flux core arc welding
In this process of welding, a wire electrode filled with flux is continuously fed so that an electrical arc is formed. The electrical arc provides the heat that is required to melt the welded metal.
Shielded metal arc welding
In this process of welding, an arc is formed between the welded rebar and electrode that has a coating of consumable flux.
Gas metal arc welding
In this process of welding, an electric arc is formed between a wire electrode and the metal. Heat is applied to the rebar that needs to be joined.
How does welded rebar help in strengthening structure
It is a well known fact that concrete is one of the most widely used construction materials. It is primarily used to lay the foundations of several buildings and structures. The vastness in the types of concrete makes it suitable for construction of foundations, piers and walls.
The only drawback that concrete holds is that it is prone to cracking. Some additional raw materials such as welded rebar make concrete strong enough to support structure and other foundations that are subjected to heavy load.
Welded rebar increases the tensile strength of concrete, thus strengthening it by increasing its reliability and durability. However, there are some practices that one must avoid during rebar welding. Here are the three main mistakes to avoid:
Lack of proper preparation
Rebar welding requires proper preparation and planning. If one misses out on this, then the output of the welding process is low-quality welds that are contaminated with dirt and paint in the welded region. The weld metal needs to be thoroughly cleaned and a round of grinding must be carried out.
Lack of proper safety measures
Most welding related injuries are irreversible and can sometimes be fatal. It is a must to wear safety gears and follow safety protocols before carrying out this process.
Usage of incorrect electrodes and wires
There are several wires and electrodes available but each has its own significance and usage. A single mistake such as choosing the wrong electrode or wire can lead to poor output. Hence, it is important to ensure that the right materials are used for rebar welding.
Wrapping it up – final words
If you have scrolled so far, we hope you have all the information that you need to know about rebar and the process of rebar welding. If you still have any queries, write to us or post comments below and we will reach out to you with everything you need.