Natural disasters such as storm, hurricane, tsunami, earthquake and random impacts can damage or destroy structures without reinforcement of round concrete columns within a few seconds, One of the best solutions is to reinforce it with FRP materials. Which is what we pay.
On the other hand , Salt water, disinfectant chemicals, and freeze-thaw cycles can cause the structure to deteriorate over a longer period of time. These structures are vulnerable to severe accidents and need to be strengthened to meet current building standards. Traditional strengthening techniques include concrete and steel jackets, But these methods are time-consuming and expensive. It also increases the cross-section of the structural column.
One new method of restoration is the use of fiber-reinforced polymers. These polymers (FRP) have excellent mechanical properties, and corrosion resistant, and endurance, light weight, and ease of use, Reduce construction time, Excellent efficiency, and longer life cycle, It is a very suitable option for use in structures.
today, The price of reinforcement using FRP is low compared to traditional methods and its implementation is easy and cheap. In this article we try to review the advantages and characteristics of strengthening round concrete columns with FRP materials in general and briefly.
Reinforced concrete (RC) columns are repaired and strengthened by FRP composites, Including FRP outer shell, والمناظر الطبيعية FRP ورش FRP. For various reasons, Including lack of enclosure, And loading outside the center, and seismic loading, accidental impacts and corrosion, Columns can be strengthened to increase axial, shear and bending capacity, Which can be part of the process of strengthening round concrete columns. With FRP material.
What are the threats to concrete column during and after construction?
If we want to address this issue briefly, It can be said that different types of damage and failure during the process of building a structure may involve a concrete column. These injuries are divided into different types that can be mentioned below.
Shear failure of concrete columns
أسوأ أنواع الفشل هو فشل القص في العمود ، Which usually appears with diagonal cuts on the shaft. The use of FRP materials while strengthening round concrete columns can prevent such discontinuities and failures in concrete columns.
Failure resulting from the creation of a plastic bending joint in concrete columns
When an earthquake occurs in columns that are not strengthened by this type of fiber, We sometimes see cracks in end parts, Which can cause loss of concrete or at least reduce its life.
Damage to the location of the covered patch of longitudinal reinforcement in concrete columns
Cause convergence and overlap between concrete column anchors, Failure to use FRP fibers and failure to implement reinforcement of round concrete columns causes this type of failure to occur and can cause serious damage to the column structure. Depending on the type of patches, In the event of an event such as an earthquake, The stiffener can be detached. this too , It is best to use fiber to overcome the negative effects of not using it.
Advantages of strengthening concrete columns and structures with FRP materials
FRP bonding systems are a useful tool to increase the axial compressive strength and also increase the ductility of the concrete unit. If there is sufficient earthquake resistance capacity, Increasing the ductility of members under axial forces and bending is one of the main goals of strengthening round concrete columns. The characteristic stress behavior of FRP-enclosed concrete is related to the determination of the confining pressure and the increase of the resulting compressive stress in the concrete.
While strengthening concrete round columns and concrete structures with FRP materials, The compressive strength of the column increases, So that FRP systems can be used to create confinement through the complete FRP shell and thus increase the compressive strength of the concrete column.
In reality , Closed concrete has a much higher compressive strength than non-closed concrete because enclosing the column causes lateral pressure on the concrete. Other advantages of using FRP materials include:
High speed of strengthening
The ability to adapt to the environment, It is an important issue in the process of using it in strengthening round concrete columns. It greatly increases the speed of strengthening. This efficiency will advance the project as quickly as possible and reduce construction time.
Low thickness
Despite what everyone thinks, The lower thickness will not change the shape of the column from its actual dimensions. This is because with this kind of thickness, It has high efficiency and high resistance in preventing damage.
Relatively low cost
Cost is always one of the most important factors in determining the type and results of work, Which entrepreneurs always take a special look at. Using FRP material in strengthening round concrete columns can greatly prevent the cost of columns and is a suitable choice for contractors and project owners.
Minimum implementation restrictions
The flexibility of this type of material in its use has made this type of fiber to be used in different types of columns. For example , Round columns that will not be installed on any type of fiber in the strengthening process due to their appearance.
Reduced weight and a slight increase in the dimensions of the base
The low weight of FRP fiber is another characteristic of this type of foundation, So that their use prevents the load on the structure to a large extent. naturally , It goes without saying that this lightness does not mean a lack of efficiency. But it will greatly prevent damage to concrete during the strengthening process of round concrete columns.