What is Steel fracture in concrete structures? 

Steel fracture in concrete structures refers to the breakage or failure of reinforcement and pre-stressing steel elements within the concrete. This fracture can occur due to various factors such as Alkali Aggregate Reaction, overloading, fire damage, or impact, but corrosion is the most common cause.  

Fracture of reinforcement or pre-stressing steel results in a significant loss of structural strength, posing a risk to the integrity and stability of the concrete structure. 

How does Steel fracture damage concrete structures? 

Steel fracture poses a significant threat to concrete structures by compromising their stability and integrity. When reinforcement or pre-stressing steel fractures, it results in a loss of structural strength, which can lead to potential failure of the concrete elements.  

This weakened structural support can lead to localized failure or, in severe cases, catastrophic collapse. Prompt detection and repair of steel fractures are crucial to prevent compromising the safety and longevity of reinforced concrete structures. 

Fracture of conventional reinforcement due to corrosion would generally be preceded by significant section loss and would be accompanied by signs such as rust staining, cracking and delamination. However, it is possible for corrosion to occur without these surface signs. 

Corrosion of stressed tendons within post-tensioned ducts present a particular problem as there may be little evidence of corrosion visible on the surface (this is of particular concern in the anchorage zone, where leakage of chloride laden water may occur).

Use of pre-stressing steel susceptible to stress corrosion or hydrogen cracking can result in brittle fracture which can lead to catastrophic loss of structural strength. Internal expansive reactions in concrete (e.g., AAR) can also lead to fracture of shear steel. 

What causes Steel fracture? 

Reinforcement corrosion or pre-stressing steel corrosion. 

Alkali-Aggregate Reaction. 

Fire. 

Low cover. 

Poor concrete quality. 

Inadequate compaction. 

Impact. 

Overloading. 

Explosion. 

Defects in grouting for posttensioning systems.

How can I identify Steel fracture in concrete structures? 

How can I repair Steel fracture in concrete structures? 

Concrete replacement with addition of reinforcement.