The mechanical properties of FRP and the bond strength between fiber reinforced polymer (FRP) rebar and concrete are among the most important aspects of the composite behavior of rebar and concrete. The mechanical properties of FRP composites depend on the proportion of fibres, base materials, manufacturing methods, mechanical properties of the component materials and the orientation of the fibers through the matrix.
Fibers can be in “continuous form” (aligned and continuous fibers are generally straight, long and parallel to each other) or in “woven form” (fibers produced in a weaving form and creating multidirectional strength) or in “cut form” (fibers are arranged Generally irregular and intermittent and known as fiberglass for short).
FRP fiber properties
Many research studies have experimentally investigated the axial compressive behavior of concrete cylinders enclosed with fiber-reinforced polymer tubes in the past two decades.
However, only a limited number of research studies have developed stress-strain models to predict FRP mechanical properties, strength and strain rate of reinforced polymer tube-coated concrete cylinders under axial compression.
Study of current shear design equations for FRP mechanical properties
The past two decades have witnessed rapid development and increase in the use of FRP reinforcement for concrete structures. Therefore, there are global efforts to create predictive models.
These efforts have led to the distribution of numerous codes and general rules. However, there is no agreement on shear models among all current codes and guidelines.
The environment required for strengthening using FRP
In such an environment, FRP reinforced polymer reinforcement can completely replace traditional steel reinforcement. In this article, the mechanical properties of FRP and durability of different types of FRP rebar and their application in bridge construction are presented.
Fiber reinforced polymer (FRP), which increases the service life of reinforced concrete structures, has been popular in structural construction over the past two decades. The use of non-corrosive FRP reinforcement has positive FRP mechanical properties such as light weight, high tensile strength, non-corrosion, and resistance to magnetic and electric fields.
However, the infinite slope of the stress-strain curve as well as the low modulus of elasticity of some FRPs compared with steel reinforcements can affect the composite performance between FRP and concrete. The contact interface between the concrete and the bar surface creates a significant bond that affects this compound action
Previous experiments that investigated the bond behavior between FRP rebar and concrete mainly focused on various factors affecting FRP reinforcement, such as concrete compressive strength, concrete cover, bar diameter, embed length, rebar casting position, fiber type, deck strip type, And focused transversely.
Study the effect of mechanical properties of FRP mesh materials
To study the effect of mechanical properties of FRP mesh materials, we must evaluate the material components and consider shear and bending stresses.
Bending bar
If two adjacent parts are placed along the length of the bar at a distance dx and in part l of the bar, the bending stresses in part dx appear as shown in Figure 1.
Strip tests are divided into two main groups:
• Output tests and
• Package tests.
Mechanical properties of FRP composite materials
The composite material consists of one or more discontinuous phases (reinforced) embedded in a continuous phase (matrix) with an interface between them. That is, the compound consists of its reinforcements in a matrix, with the interface acting as a link between them.
Performance-specific design of composite materials shows that a wide range of factors affect the mechanical properties of FRP composite
The following list provides a summary of potential factors that can alter the mechanical properties of FRP composites and affect their performance.
Properties of composite components
Distribution of components
Interaction (bonding) between components
The geometry of the reinforcement, especially the shape, size, and size distribution
Concentration or volume of strengthening
Homogeneity or uniformity of the complex system
Component routing
Technical specifications of FRP materials for reinforcement components
As mentioned earlier, the technical properties of FRP materials improved over the original components are the most desirable properties for composites, for example, strength, rigidity and durability. These mechanical properties of FRP actually depend strongly on the type and geometry of the reinforcement.
Composites are generally classified into fiber-reinforced composites or particle-reinforced composites based on the reinforcement geometry.
Fiber reinforced composites derive their properties mainly from FRP reinforcement. Like reinforcements, fiber composites are typically strong and rigid and can perform well at high temperatures. On the other hand, the mechanical properties of FRP composite particles are mainly derived from the matrix.
Physical and mechanical properties of FRP
One of the issues emphasized by the company is strengthening the physical and mechanical properties of FRP. By emphasizing these characteristics, they have succeeded in building stronger foundations and have been able to apply new innovations in this field.
It should also be noted that Pekran Sazan Company has achieved many successes in the field of strengthening building materials and concrete using FRP fibers and has been able to take great steps in this direction to strengthen towers and modern buildings. For more information about the physical and mechanical features of FRP emphasized in the reinforcement company, read the article FRP Composite Reinforcement Mesh to learn about new methods of strengthening with FRP.