Vector Corrosion Services

VCS News & Corrosion blog

Distributed Galvanic Anode on Bridge

Embedded Galvanic Anodes for Concrete

Submitted by: Chris Ball

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Currently, there are two general types of embedded galvanic anodes generally categorized as discrete anodes and distributed anodes.

Discrete embedded galvanic anodes are covered in ACIs Repair Application Procedure Bulletin 8 (RAP-8).  The RAP-8 bulletin classifies discrete embedded anodes as Type 1 Anodes - used to mitigate halo effect in standard concrete repairs, and Type 2 Anodes – typically used to provide targeted corrosion control to hot spots as identified by a corrosion potential survey.   RAP-8 further classified embedded anodes as Type A – alkali-activated and Type H – halide activated.

Distributed galvanic anodes are long units generally 3’- 8’ in length that are available in a weights ranging from ¼ to 2 lb. zinc per foot of anodes.  These systems can be designed to provide cathodic protection in many applications such as column jackets, abutment repair and deck overlays.

Having a thorough understanding of the benefits of uses of galvanic protection for concrete, VCS's NACE Certified Cathodic Protection Specialists are available to assist structural engineers and owners with all of their cathodic protection design, cathodic protection inspection, and system monitoring needs.

Caesar's Bay Cathodic Protection

VCS Receives ICRI Award

Submitted by: VCS Marketing

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Last night - November 10 - at the at the 2016 International Concrete Repair Institute Award program in Cleveland, Vector Corrosion Services (VCS) was the receipient of the Award of Merit for the Cathodic Protection of Caesar's Bay Shopping Center

Caesar’s Bay Plaza is a retail complex along Gravesend Bay in Brooklyn, NY.  The elevated building floor sections are subject to both airborne chloride as well as splashing when waves crash into the bulkhead.

Despite previous repairs, the structure continued to degrade over time.  With the retail complex on top of the structure, replacement is not a practical option.

VCS was tasked to design, provide on-site quality control, and energize an impressed current cathodic protection (ICCP) system to protect the decaying concrete beams.  The cathodic protection system selected consisted of discrete anodes and associated wiring and power supplies.

 ICCP Concrete Beam.jpg

Despite winter conditions, difficult access, and various trades working in the same location, the cathodic protection system was successfully installed over a 10 month year period.  The system was energized in the fall of 2015 and is performing according to the design and meets NACE cathodic protection criteria. 

For more information, Click Here for a PDF of the announcement in the December 2016 issue of ICRI's Concrete Repair Bulletin.

Key Words:  Marine Structure, Coastal Structure, Concrete Corrosion, Concrete Repair, Concrete Wharf, Concrete Durability, Cathodic Protection

Galvanic Jacketing of Bridge Columns

Cathodic Protection Jackets for Concrete and Steel Piles

Submitted by: Chris Ball

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Concrete piles in a marine environment are subject to chloride-induced corrosion from exposure to the seawater and airborne chlorides.  A commonly employed option to repair and extend the life of corroding concrete piles is the use of cathodic protection jackets.  

CP Jackets are available using impressed current cathodic protection from an external power supply, galvanic protection with bare zinc anodes, and galvanic protection using self-activated anodes. As detailed in this recent Aspire Magazine article, each jacket type has its advantages.  For example, impressed current jackets may be used when large groups of piles are protected and the owner is committed to long term system monitoring.  On the other hand, self-activated anodes do not require any direct saltwater exposure whatsoever as they function well in atmospheric (dry) zones and brackish or freshwater exposure conditions.  

VCS provides cathodic protection design, quality control oversight and commisioning services for cathodic protection pile jackets through its NACE certified Cathodic Protection Specialists (CP4) and NACE certified Cathodic Protection Technicians (CP2).  For more information contact VCS at info@vcservices.com.  

GPR Signal for Void Under Concrete Slab

Detecting Under Slab Voids using Ground Penetrating Radar

Submitted by: Dr. Brian

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Ground penetrating radar (GPR) is an electromagnetic nondestructive test (NDT) method used to evaluate various dielectric materials.  Most commonly, GPR is used to investigate concrete and soils.

GPR has many applications, such as determining the location and depth of concrete cover over reinforcing steel in concrete, however, one of its most effective applications for detecting voids underneath a concrete slab-on-grade.  Voids under concrete slabs can be caused by many factors including subsidence, improper subgrade compaction, and washout due to water drainage.

When concrete is in contact with soil the boundary between the concrete and soil is not easily identifiable.  When an air or water void is between the concrete and soil, the boundary of the slab can be identified using GPR.  Thus, GPR scans of a concrete slab-on-grade can be conducted to identify locations of voiding. 

A limitation of GPR is that it cannot identify the thickness of the observed void.  Therefore, drilling a small hole through the slab for video borescope inspection will provide more information regarding the void condition and thickness.  This information can be used to determine the proper repair technicque such as under slab cement grouting or slab jacking if the slab needs to be raised and to estimate the quantity of repairs.

For more information on non-destructive testing for concrete structures, please contact Vector Corrosion Services at info@vcservices.com.

Service Life Modeling on Sheet Piles

Service Life Modeling

Submitted by: VCS Marketing

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What is Service Life Modeling? 

Service life modeling and life cycle cost analysis are the analytical basis for assessing preferred options for new construction and rehabilitation projects.  Service life modeling is using mathematical analyses to predict the durability and longevity of new and existing structures.  Service life modeling allows you to estimate the time to initiate corrosion, develop optimized repair strategies for reinforced concrete, and perform life cycle cost analysis.  Data collected during an on-site concrete and corrosion evaluation is coupled with service life modeling to analyze existing structures.  

What Factors affect the Service Life of Concrete Structures?

There are many factors that concrete service life models take into account such as concrete mix design, concrete properties, chloride and carbonation diffusion rates, depth of clear cover, structure location, reinforcing type and environmental exposure conditions.

When is Service Life Modeling typically utilized?

Service life modeling is used to make cost effective decisions regarding the durability of new structures and to develop maintenance and repair programs to extend the life of existing structures.  Service life modeling can be used to answer questions such as “How do I achieve a 100 year service life of bridges subject to deicing chemicals?” or “What are the most cost effective methods for concrete repair and protection of a marine structure?” 

As cathodic protection is typically considered a cost-effective option for to extend the life of concrete and steel structures, there is a benefit in engaging an engineer with significant experience in both service life modeling and cathodic protection.   For more information on service life modeling and life cycle cost analysis, contact Matt Miltenberger at Vector Corrosion Services.

GCP of Sheet Pile with Aluminum Anode

Steel Sheet Piling Corrosion Solutions

Submitted by: Matt Miltenberger

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Steel sheet piles are at risk of corrosion when installed in corrosive soils or an aggressive marine environment.  The service life of new and existing sheet pile can be modeled based on steel thickness measurements and estimated corrosion rates.  Potential strategies to extend the life of sheet piling are increased sacrificial steel thickness, organic barrier coatings, impressed current cathodic protection (ICCP) and galvanic cathodic protection (GCP).  Vector Corrosion Services provides corrosion consulting services to aid engineers in the selection and design of cost effective corrosion control approach for steel sheet piles and other structures subject to corrosion damage.  For more information, contact VCS at info@vcservices.com.

NDT Data Presentation Methods

Dr. Pailes' Research on Nondestructive Testing Published by TRB

Submitted by: Admin

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Dr. Brian Pailes research paper Multimodal Nondestructive Testing Damage Quantification, Presentation and Condition Rating of Bridge Decks was recentlypublished in the Transportation Research Board's Transportation Research Record.

In his research, various NDT methods such as half cell corrosion potentials, electrical resistivity, ground pentrating radar, and impact echo were employed on 5 bridges in the US.  The multimodal NDT evaluation allows for an evaluation of the interior condition of the deck and provides a more in-depth snap shot of the bridge deck condition as compared with a visual inspection.

The field results showed that there was more damaged detected with NDT than with standard inspections.  Based on the research, it is proposed that including NDT data in bridge deck ratings will provide more useable information than a standard NBIS rating.

Multimodal NDT is an effective tool for bridge engineers to develop damage quantities, develop repair and corrosion mitigation strategies, and to improve budgeting.  For more information on nondestructive evaluation of structures, contact VCS at info@vcservices.com.

Reference:  Transportation Research Record:  Journal of the Transportation Research Board, No. 2481, Transportation Research Board, Washington, D.C., 2015, pp. 26-31.  DOI:  10.3141/2481-04.

Vector Corrosion Services

VCS Hiring a Project Engineer

Submitted by: Chris Ball

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Vector Corrosion Services (VCS) is a leading provider of solutions to improve the durability of buildings and infrastructure.  We are searching for a Project Engineer to join our technical staff in Wesley Chapel, Florida.  

 

RESPONSIBILITIES

  • Provide operational support to Project Managers
  • Field investigation of corrosion problems
  • Perform non-destructive testing
  • Test cathodic protection systems
  • Install corrosion monitoring instrumentation
  • Technical report writing

 

SKILLS & APTITUDES

  • Excellent verbal and written communication
  • Self-motivated and eager to learn
  • Adaptable / able to handle multiple tasks
  • Enjoy hands-on work
  • Basic knowledge of concrete and electrical systems
  • Proficient in MS Office applications
  • Basic drafting skills
  • Enjoys travel

 

QUALIFICATIONS

  • B.S. in Engineering or another technical field
  • NACE certification preferred
  • Capable of working in a standing or stooping position for long periods of time
  • Lifting of 50 lb.
  • Familiar with safe work practices in a construction environment

 

Candidates with a background in construction inspection or construction management are encouraged to apply.  A pre-employment background check including drug screening is required. For more information about VCS, visit our website at www.vcservices.com.  Interested candidates should email a resume and salary requirements to Vector Corrosion Services.

US Transportation

60 Minutes Documents the State of US Infrastructure

Submitted by: Chris Ball

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This video illustrates a growing problem that VCS is committed to solving. Steve Kroft reports on why our roads, bridges, airports and rail infrastructure are deteriorating and need to be fixed. 

Falling Apart: America's Neglected Infrastructure

Click this link to view the video!

Dr. Brian Pailes

Dr. Brian Pailes Presents at ASNT

Submitted by: Chris Ball

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Dr Brian Pailes presented a paper titled "Evaluation of NDE Survey Effectiveness Based on Sampling Frequency."  The paper, based on his research at Rutgers University, reviewed how sampling frequency affected non-destructive survey results from 12 concrete bridge decks.