1. HOW DOES KRYSTOL AFFECT
CORROSION OF REBAR
ALIREZA BIPARVA
Research & Development Manager / Concrete Specialist
Kryton International Inc.
www.kryton.com
4. www.kryton.com
WHAT IS THE COST OF CORROSION?
Corrosion is the main cause of damage and early failure of reinforced concrete
structures.
Makes up more than 80% of all damages of the reinforced concrete structures.
In the United States alone, the total annual repair costs associated with
concrete deterioration is estimated to be $300 billion.
Nearly 95% of concrete damage in the GCC’s coastal region is caused by
reinforcement corrosion and consequent spalling of concrete.
5. www.kryton.com
WHY STEEL IS NEEDED IN CONCRETE?
Concrete is one of the most widely used construction materials with many advantages
such as:
• Formability;
• Durability;
• High compressive strength‐Typical Compressive Strength: 20‐40 MPa;
But
• It is weak in tension ‐ Typical Tension Strength: 2‐5 MPa.
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WHY DOES STEEL IN CONCRETE CORRODE?
Due to the high‐alkalinity of concrete, the
steel reinforcing bars are passivated by an
iron oxide film (Fe2O3) that protects the steel.
SO
Concrete normally provides reinforcing steel
with excellent corrosion protection.
UNTIL
The passive layer breaks down.
Photo Courtesy of PCA
15. www.kryton.com
WHY DOES STEEL IN CONCRETE CORRODE?
Different systems such as chloride ions can break down this passivity and allow
the steel to actively corrode.
The Corrosion Cell
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HOW DOES CORROSION AFFECT THE INTEGRITY OF A
CONCRETE SRUCTURE?
Products of corrosion (rust), occupy a greater volume than the original steel
Staining, cracking, and spalling of the concrete
This expansion creates tensile stresses in the concrete
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WHAT IS THE EFFECTIVE CORROSION CONTROL SYSTEM?
Either
• Extend the time to corrosion initiation; or
• Reduce the corrosion rate of embedded steel; or
• Both
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WHAT ARE THE TYPICAL CORROSION PROTECTION
SYSTEMS?
Traditional measures to mitigate corrosion are:
• Cathodic Protection
• Corrosion Inhibitor admixtures
• Anti‐corrosion coating
And
• Using less permeable and durable concrete
29. www.kryton.com
HOW TO CONSTRUCT DURABLE STRUCTURES?
The penetration of water into concrete is a critical factor in the corrosion of
steel reinforcement.
• Water acts as a carrier for chloride ions, and
• Water is required for corrosion to occur.
Therefore, the first line of defense against corrosion is to prevent the
penetration of water into the concrete.
30. www.kryton.com
With the exception of mechanical damage, all the adverse influence on durability
involve the transport of fluids through the concrete.
(Properties of Concrete, Neville)
Water Permeability determines the rate of deterioration
Service life - Durability
HOW TO CONSTRUCT DURABLE STRUCTURES?
31. www.kryton.com
Concrete is a hard material with a network of openings
(capillaries, pores, cracks and micro cracks)
Water can pass through unprotected concrete
Water can directly damage concrete (Freeze – Thaw).
Water acts as a carrier of aggressive chemicals (Chloride).
HOW TO REDUCE PERMEABILITY OF CONCRETE?
35. www.kryton.com
Crystalline waterproofing as an admixture (KIM) was invented and
pioneered by Kryton during the 1980’s.
Powdered form:
• Added into the concrete mix at 2% of the cementitious content
• Added directly to ready mix truck or at the batch plant
• Effective against hydrostatic pressure
WHAT IS INTEGRAL CRYSTALLINE WATERPROOFING?
38. www.kryton.com
HOW TO SELECT THE BEST SOLUTION?
Long Term Hawaii Study
Which product is best to do the job of protecting your steel from
corroding?
A long‐term field exposure study was conducted
(2002‐2012) to evaluate the durability of reinforced concrete
specimens exposed to an aggressive marine environment.
41. www.kryton.com
HOW TO SELECT THE BEST SOLUTION?
Long Term Hawaii Study
Corrosion
Inhibitor
Control
Waterproofing
admixture (densifier)
Kryton
(KIM)
42. www.kryton.com
HOW TO SELECT THE BEST SOLUTION?
Long Term Hawaii Study
The key findings in the reports are as follows:
• The panel using KIM outperformed all other chemical
admixtures.
• KIM panel showed significant reduced half‐cell reading when
compared with the control specimen.
• In addition, after 10 years exposure, KIM panel does not have
any signs of corrosion.
43. www.kryton.com
HOW DOES KIM AFFECT CORROSION OF REBAR?
KIM
Self‐Sealing
Crystallization
Reduce Permeability
Cont. Heat of Hydration Control Bleeding
Reduce Cracking
Inhibit Water and
Chemical Penetration
Extend Initiation Reduce Corrosion Rate
Reduce Corrosion of Rebar
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