Conditions That Can Seriously Damage the Integrity of Concrete Structures

Concrete Structures

Concrete is probably the oldest known construction material in the history of civil engineering. Greeks and Egyptians used lime-based concrete in 2000 BC. In the 17th Century, steel-reinforced concrete was developed following the invention of prestressed concrete in 1928. Throughout the history, researchers and corrosion experts have struggled to develop a concrete reinforcement material that could provide a defensive mechanism against corrosion. In this blog post, I will discuss some of the conditions that seriously damage the strength and life of a reinforced concrete.

1. Aggregate expansion

Aggregates experience chemical reactions in concrete which leads to concrete deterioration. When water freezes, the excessive water absorption makes it difficult for aggregates to accommodate hydraulic pressure and expansion. The process leads to concrete disintegration. Concrete can be restored to its normal strength if it has been frozen at an early age. However, frozen concrete does not remain as effective against weather as the concrete which had not been frozen.

Aggregate expansion

D-cracking is one the types of concrete deterioration caused by aggregate expansion. It is often observed in pavements because of the natural accumulation of water. Concrete can be made effective against weather conditions by selecting aggregates that perform better under severe weather conditions.

2. Chemicals

The exposure to chemical environments can degrade even the superior quality concrete. Sulfuric acid, aluminum chloride, and hydrochloric acid are few of the chemicals that accelerate concrete deterioration. Groundwater and soil contain sodium, magnesium, calcium and other chemicals. When these chemicals react with hydrated compounds in concrete, the process badly affects the strength and durability of concrete. Carbonatation-initiated deterioration of concrete is an example of the chemical attack. Chemical attacks can be avoided by reinforcing concrete with bars that are resistant against environmental conditions. Marine structures are more vulnerable to corrosion as they have to withstand the most severe environmental conditions.

3. Erosion

Erosion refers to a condition where concrete surface is damaged by friction. As the outer layer of concrete wears, it facilitates the degradation process by exposing the coarse aggregate. Roads and hydraulic structures experience the worst form of erosion. The use of studded snow tires, for instance, damage the outer surface of roads. In dams, spillways, and other hydraulic structures, the waterborne elements lead to abrasion damage.

4. Heat

Concrete can be damaged by fire. High temperature affects modulus of elasticity, flexural and compressive strength of concrete. Temperature over 300 Celsius grades is considered to be unhealthy for concrete. A rapid exposure to very high temperature can create steam inside concrete that leads to explosive spalling.

There are several factors that can cause concrete degradation. However, high-quality reinforcement material can protect concrete structures from corrosive agents, radiation, heat, weather, and physical damages. Fiberglass rebar is an emerging construction solution which deals exceptionally well with severe environmental conditions, enabling concrete structures to withstand corrosive agents, heat, radiation, friction, and other dangerous phenomena for more than 100 years.

How is FRP the Best Earthquake-resistant Material?

Glass fiber-reinforced polymer (GFRP), formed by glass fibers bonded in a matrix made of vinyl ester, has been employed extensively in a number of rehabilitation applications, particularly seismic retrofitting. Seismic retrofitting is a technique to modify the existing concrete structures to make them protected against soil failure and seismic activities. The immunity to corrosion, high strength-to-weight-ratio, and convenient handling and installation make fiberglass rebar a material of choice in a large number of projects where inelastic deformation capacity and high strength are the prerequisites.

Fiberglass-FRP

Fiber reinforced polymer (FRP) has widely been recognized as an effective seismic retrofit material for new and existing concrete structures. When it comes to the authenticity of fiberglass reinforcement in seismic regions, Japan is a leading country in terms of applications of fiber reinforced polymers reinforcement for concrete. We all know Japan is one of the world’s most earthquake-prone country.

Studies to investigate the possible deficiency of concrete structures in seismic regions reveal that the main failure of columns was due to the insufficient ductility of structures and shear strength. The effectiveness of fiberglass material to confine concrete columns has been acknowledged on a global scale. The structural deficiency of existing buildings in seismic regions is a critical problem. However, the concept of seismic design of structures is not very old. In seismically active regions of the world, the improvement in structurally deficient concrete columns has been a proven and most significant application of fiberglass materials.

The traditional technique of seismic retrofit of concrete structures is no longer a practical solution; repairing damaged structures with steel demands plenty of time. In addition to this, steel is susceptible to corrosion and increases the stiffness of the columns exposing a structure to higher transmitted seismic forces. While on the other hand, fiber reinforced polymer composites enable engineers to repair structurally deficient structures in a time-efficient manner.

The maintenance of deteriorated civil engineering infrastructures is costing builders millions of dollars. Earthquakes, aging, and other extreme environmental and geographical conditions are some of the major reasons behind global infrastructure crisis. Currently, retrofitting of concrete structures by fiberglass construction material is one of the most practical schemes to improve seismic resistance.

The use of fiber reinforced polymers, as a construction material has increased considerably over the past couple of decades, primarily because of its higher durability and corrosion resistance. That is why fiberglass rebar has turned out to be an ideal construction material for rehabilitation, seismic retrofitting, and disaster-resistant buildings.

Advantages of Using Glass Fiber Reinforced Polymer (GFRP) Rebar

GFRP

The composite material was first produced in the 1960s. Fiberglass reinforced polymer (FRP) was commercially recognized in the 1980s when it was used in high-speed trains project by Japan. The question is why engineers need composite material to build strong and long-lasting projects and why traditionally-used reinforcement materials lack strength. The answer is associated with corrosion which shortens the service life of a concrete structure. Therefore, engineers and builders need to reinforce concrete structures with material that can survive the harsh environmental conditions.

FRP rebar is gaining commercial value mainly because it is resistant to corrosive agents and does not let concrete rust or weaken. GFRP or glass fiber reinforced polymer rebar is a variant of FRP. Advanced composite materials like FRP was adopted by US and Canada for structural applications in the late 1990s. Sensitive concrete structures like seawalls, dams, and power plants have to be reinforced with corrosion-resistant rebar. Fiberglass reinforcement material, therefore, is considered to be the ideal product for sensitive concrete infrastructures.

Advantages of GFRP Rebar:

Glass fiber reinforced polymer rebar is a high value-added construction product. The mega infrastructure providers, such as governments, now have acknowledged the fact that GFRP is a cost-effective construction material that has the full potential to extend the life of public structures where corrosion can have a huge economic and environmental impact. With the rise of corrosion due to global warming, fiberglass reinforcement material has gained considerable popularity. In future, these advanced composite materials would demonstrate their strengths and properties more evidently. Here are some of the advantages of using GFRP rebar in various applications:

  • The constituents of GFRP include high-quality corrosion resistant vinyl ester resin that increases the lifespan of a concrete structure.
  • As compared with the traditional reinforcement material, GFRP rebar is ¼ the weight of steel with 2x the tensile strength of steel.
  • GFRP rebar is non-conductive to electricity and heat making it an ideal choice for facilities like power generation plants and scientific installations.
  • Taking into account the long-term benefits of GFRP rebar, it is a cost-effective product as compared with epoxy-coated or stainless steel.
  • It is invulnerable to chloride ions and other chemical elements.
  • It can be manufactured in custom lengths, bends, and shapes.
  • The installation process of GFRP rebar is very convenient coupled with its property of being easy to cut and machined.
  • It is transparent to electrical field and radio frequencies
  • A project reinforced with GFRP rebar is maintenance free, enabling builders to avoid rehabilitation cost.

It may seem that fiberglass reinforcement is expensive while other traditional steel reinforcement is relatively inexpensive. In fact, fiberglass rebar is a cost-effective building material as it gives a concrete structure long lifespan without major maintenance.

The Best Concrete Reinforcement Solution for Marine Structures

Marine structures, such as seawalls, submarine tunnels, piers, and groins, are engineering facilities which are constructed as a source of development and marine resource exploitation. Rock, sand, concrete, and steel are some of the conventional materials used in marine applications. Marine concrete structures have to withstand the extreme environmental pressure. They are subject to corrosive agents which can corrode the reinforcing steel causing spalling, rusting, and shortening the service life of the structure.

buildings

Corrosion and marine environment

Corrosion can simply be described as the deterioration of a metal by an electrochemical reaction. The pH of the concrete can fall when it became carbonated, causing the loss of passivity. The passivation layer is broken when chlorides reach the steel. Some of the common causes of corrosion are:

  • Chloride-containing admixtures
  • Sea water
  • Airborne chlorides
  • Carbon dioxide in the atmosphere
  • Sea dredged aggregates
Concrete-Reinforcement-Solution

Corrosion process forms rust, causing a seven times increase in the volume of reinforcement bars. The dramatic change in volume causes spalling of the concrete surface making it even more vulnerable to aggressive environment. The abundance of moisture and chlorides make the environment extremely harsh for marine construction projects. Some of the structure that are build in or close proximity to oceans are:

  • Retaining walls, seawalls
  • Floating structures
  • Decks, quays, and piles
  • Boat ramps, jetties, and bulkheads
  • Roads, buildings, and aquariums

How to control corrosion

So far as marine structures are concerned, reinforcement concrete needs to be a highly durable and corrosion-free structural material demanding little or no maintenance. Without correct mixing, design, placement, and curing, the durability of concrete can be impaired. Good practices and quality material can play a role in minimizing the direct maintenance cost and increasing the life cycle of a sensitive concrete structure.

GFRP reinforcement

Glass fiber reinforced polymer (GFRP) reinforcement has compelling mechanical and physical properties that make GFRP particularly attractive for marine structures operating in aggressive environments such as coastal regions, public infrastructure, and buildings that host sensitive equipment. The property of being corrosion-free makes fiberglass rebar a perfect alternative to conventional steel bars which cannot resist rust. Pultrusion is the manufacturing process used to produce fiber reinforced polymer (FRP) bars.

fiberglass rebar alberta

Marine structures reinforced with fiberglass rebar are invulnerable to strong chlorides and moisture. When bonded in concrete, GFRP or fiberglass bars do not react to chemical products, salt, and alkali. Fiberglass rebar is not manufactured with steel or any other metal the pultrusion process helps produce fiberglass rebar that is twice the tensile strength of steel bars. Furthermore, GFRP bars do not interfere with the sensitive electronic equipment.

5 Reasons Why You Should Use Fiberglass Rebar In Your Project

The popularity of glass fiber reinforced polymer (GFRP) is on the rise particularly in applications where corrosion-resistant is a major concern. We know that corrosion is a costly problem. Trillions of dollars are spent annually on resolving issues related to metallic corrosion. So far as facts are concerned, the annual direct cost of metallic corrosion is over 2.2 trillion US dollars. The United States alone spend 423 billion dollars as an annual cost of corrosion.

Steel corrosion is a natural and global phenomenon. You can understand now how much money we can save if we employ corrosion protection methods properly. Let’s talk about corrosion in detail before we can move on to how glass fiber reinforced polymer can save your projects from corrosive agents.

Definition and effects of corrosion

Steel and iron have that natural tendency to mix up with chemical elements so that they could return to their lowest energy states, similar to the tendency of water that flows to the lowest point. When iron and steel combine with water and oxygen, hydrated iron oxides, also called rust, is formed. Corrosion can simply be defined as a chemical reaction between a material and its environment. This chemical or electrochemical reaction causes deterioration of materials.

We are well aware of how corrosion has been effecting service lives of our possessions. Incidents such as collapsed bridges and damaged sections of highways are some of the common sights that directly linked to corrosion. Following are the reasons why you should use fiberglass rebar in order to dramatically increase the service life of your project.

fiberglass rebar

  1. Fiberglass Rebar is corrosion-resistant

    As it is mentioned in the start that glass fiber reinforced polymer has gained considerable space over steel in applications where corrosion is a big threat. Fiberglass rebar offers a comprehensive corrosion solution. A concrete structure reinforced with fiberglass rebar does not react to the chloride-rich environment.

  2. A perfect alternative to traditional concrete reinforcement

    Glass fiber reinforced polymer (GFRP) rebar has turned out to be a perfect alternative to traditional reinforcement materials such as black rebar and epoxy coated rebar. Traditional reinforcement techniques have failed to develop a corrosion-free mechanism that can keep concrete structures in good shape.

  3. Long service life

    Glass fiber reinforced polymer, chemically inert reinforcement, is an economical way of achieving a long service life of your project. Old reinforcement materials might seem inexpensive, however, they can cost you a lot of money in the long-term. By applying fiberglass rebar, you can not only save money in long-term but also make your project completely rust free.

  4. A wide range of applications

    Fiberglass rebar can be used in a wide range of applications including marine structures, IT, and medical facilities. It is non-conductive and non-magnetic construction material ideal for medical and scientific facilities.

  5. Save time and money

    Maintenance cost multiplies the amount spent on inexpensive concrete reinforcement bars. Sustainability is one of the biggest concerns for the projects built with steel rebar. Fiberglass rebar provides sustainability by making concrete structures invulnerable to corrosive agents. Make sure you are using the right material for your construction projects that can save you money and time in the long-term.

One Incredible Alternative to Conventional Concrete Reinforcement Techniques

Reinforced concrete is a composite material in which reinforcement is included in order to address concrete’s low ductility and tensile strength. Rust remains one of the major problems associated with traditional reinforcement methods. There is no denying the fact that rust is cancer for concrete. The inability of steel reinforced bars to fight harsh environment demands costly repair and maintenance in the long-term.

Last four decades have witnessed a great deal of research to develop corrosion-free construction solutions capable of extending the service life of civil engineering structures, enhancing the performance of infrastructures under severe environmental and loading conditions. Extensive research has been carried out to develop modern construction materials with improved durability and environmental resistance.

Reinforced concrete experts have come up with Fiber-reinforced polymer (FRP) reinforcement as a durable and corrosion-free construction solution that has the power to extend the lifespan of a concrete structure up to 100 years. Glass, carbon, and aramid are frequently used fibers for FRP reinforcement. One of the most highlighted benefits of FRP is that it is not susceptible to chloride-initiated corrosion in concrete. This property of FRP reinforcement makes it an ideal choice for engineers to build concrete structures that can survive the severe environment for a long period of time.

Incredible Alternative

When it comes to the value of a composite material, durability is the defining feature. As a part of the evaluation process to determine the durability of glass fiber reinforced polymer (GFRP) reinforcement, a number of tests have been conducted to determine its strength against different stress levels and environmental conditions. This relatively new construction material has been accepted by a large section of the building industry in North America as well as in other parts of the world.

Distinctive features of GFRP reinforcement

How is GFRP reinforcement an incredible alternative to conventional and outdated reinforcement material? When GFRP composites are compared with traditional reinforcement materials, GFRP reinforcement outclasses traditional reinforcement in high strength-to-weight ratio, thermal and electric insulation, corrosion resistance, low maintenance cost, flexibility, and installation cost.

When we construct a project with materials that cannot withstand the harsh environment, plenty of resources are consumed to repair and maintain the integrity of a structure. What if we use quality building material at first place and avoid the direct outlay of maintenance funds. The prime objective of developing fiberglass reinforcement products was to construct concrete structures which can achieve long service life without receiving maintenance or repair.

As an initiative to make the production of fiberglass reinforcement more environment-friendly, TUF-BAR started manufacturing superior quality fiberglass rebar in 2000. Their fiberglass reinforcement rebar has been serving as a durable and lightweight alternative to traditional steel products.