Corrosion Prevention & Control (CPC) Design & Construction Issues  

Date: 
12-04-2017

Joseph C. Dean, P.E. for the Director, Corrosion Policy & Oversight (D, CPO) [OUSD (AT& L)

 

INTRODUCTION

Although, the word "corrosion" is most often associated with "rust" and the oxidation of other metals, 10 U.S.C. § 2228 defines corrosion as, "the deterioration of a material or its properties due to a reaction of that material with its chemical environment." It is inclusive of the deterioration of all materials, which can be caused through sun exposure, mold and mildew, wind, and other environmental elements.

Description

Facilities affected by corrosion include pipelines, fuel tanks, pavements, roofs, transformers, switchgear, electrical boxes, HVAC equipment, water towers, fire hydrants, motors, compressors, bridges, wharfs, piers, connectors, fencing, boilers, ladders, stairways, wash racks, fire sprinkler systems, airfield pavements, steam, tankage, POL and water distribution lines. Corrosion effects often remain unseen or unnoticed until failure occurs. Facility vulnerability and the potential effects of corrosion need to be fully evaluated and understood as a requirement. It should be included in project planning, acquisition (RFP and SOW), design, construction, and sustainment phases and activities. See the High-Risk Facility Types and Components Table for additional insights.

The Whole Building Design Guide (WBDG) hosts a large number of corrosion related criteria and Corrosion Prevention and Control (CPC) resources. The CPC Criteria Web Page provides Design Engineers, Architects and Construction professionals with a summary of CPC related criteria to assist in making informed durability and longevity decisions for the selection of materials and design development.

Design And Construction Expectations

DoD facilities should be designed and constructed to meet the following expectations:

  • Selecting and specifying materials and coatings that have low life cycle costs (LCC), are durable, and minimize the need for preventative and corrective maintenance. Initial investments in corrosion prevention are typically more LCC-effective than maintenance, repair, and replacement of prematurely degraded components.

  • Designing and specifying facilities to reach intended life cycle expectations, including the use of enhanced materials and coatings in severe corrosive environments. It is typical for many DoD facilities to be in service in excess of 50 years. Foundations, structural elements, utilities, piping, insulation, and other building components that are buried or located in walls, ceilings, crawl spaces, interstitial spaces, and duct banks should be designed considering these service life realities.

  • Ensuring that design and construction are inclusive of the realities of maintaining a facility after the project is completed. Convenient access to maintenance points such as HVAC filters, shut off valves, drain pans and control panels, for example, should be provided to ensure that the risk of corrosion and facilities damage will be decreased and maintenance activities optimized.

  • Including assessment of environmental severity (see UFC 1-300-02) impacts and the appropriate selection of CPC materials (e.g. coatings, grades of steel, humidity controls, etc.) appropriate to the locale to reduce the risk of corrosion vulnerability.

  • Any trade-offs required during acquisition stages must include the selection and application of design criteria that will prevent or mitigate future corrosion, improve sustainability, durability, key dimensions of longevity, and reduce cost over the facilities' life cycle.

Good corrosion performance is both an attribute of an entire facility and the sum of its sub-components including leveraging Best Practices, understanding regional or environmental severity influences, and leveraging the associated knowledge of facility requirements to achieve a successful solution.

Design

Corrosion vulnerability must be fully evaluated and addressed as part of the development of the RFP, contractor selection, the subsequent design, construction, and throughout the supporting Quality Assurance (QA), Quality Control (QC) and Commissioning (Cx) activities. CPC Acquisition Issues and CPC Competencies pages provide additional insights into factors affecting Design and Construction. If CPC is not considered during the planning process or during development of the RFP, Source and Contractor Selection, the designer of record must make the best life cycle design decisions. Low cost solutions always result in life-cycle reduction.

DoDD 4270.5 Military Construction (February 12, 2005) requires the use of UFC and UFGS criteria hosted on the Whole Building Design Guide. If necessary, editing guide specifications (e.g., UFGS) with prescriptive CPC requirements may be necessary.

CPC related design includes the full range of efforts from corrosion problem solving to selection of criteria, development of plans and specifications to completing the work via in-house forces or by contract. The High-Risk Facility Types and Building Components for CPC will provide additional insights into risks and other factors affecting CPC Design. A complete understanding of Corrosion Science will help the designer to make informed material selection and facility design decisions.

Design detailing and assembly of components are as important as the material and coatings for the individual component. Identifying the corrosive forces and employment of CPC design strategies include:

  • Selection of materials to prevent dissimilar metal corrosion
  • Use protective coatings, isolators, & corrosion inhibitors
  • Consider alternate materials for components proximate to salt water and in areas of high environmental severity
  • Shelter building components to reduce corrosive exposure and time of wetness
  • Prevent entrapment of water
  • Insure integrity of building envelope design (UFC 3-101-01 Architecture, with Change 3)
  • Consult with subject matter experts

Corrosion related problem solving may require analysis of an issue such as the cause of mold or the untimely appearance of rust. The Engineer and or Architect Designer must then determine what corrective measures are required; the solution might include dehumidification, selection of a specialized coating, or determining which type of power pole should be used as a replacement in a highly corrosive soil area. These "solutions" may not require full plans and specifications, however, some level of specificity is required in the contract documents or job order to ensure that the appropriate solution is realized.

Differing acquisition strategies and delivery methods (e.g. Design/Bid/Build (DBB), Design-Build (DB), Simplified Acquisition, Task Order/Indefinite Quantity Job Order Contracts, etc.) should consider and include CPC in requirements definition, RFP and execution. The majority of DoD military construction, repair, and renovation projects use either the Design-Bid-Build or the Design-Build acquisition strategy. Although both strategies have similar requirements for corrosion prevention and control, they are usually employed in a different manner based on contracting differences.

The Design-Bid-Build (DBB) acquisition delivery method relies on the Scope of Architect/Engineer Services to identify the contract design requirements. Design-Build (DB) acquisition delivery method where the contractor provides the design is the prevalent acquisition strategy for Military Construction Projects. This delivery method relies on the Request for Proposal (RFP), to identify both the design and construction requirements. Here are several considerations related to CPC for each delivery method:

  • Identify the need for corrosion prevention and control in the Scope of Architect/Engineer (AE) Services (DBB)

  • Provide information on environmental severity and identify environmental severity considerations in the design (DBB and DB)

  • Insure soil PH and resistivity is provided or add to scope of AE services for utility projects and buried structures (DBB and DB)

  • Identify corrosive impacts from user operations and equipment (DBB)

  • Insure corrosion prevention is discussed at the initial design charette and implemented on the plans and specifications at each submittal stage (DBB)

  • Insure test requirements and quality control procedures are identified in project specification for components requiring enhanced corrosion protection and coatings (DBB and DB)

  • Identify building components that require enhanced corrosion prevention materials and coatings (DBB and DB)

  • Identify the corrosion prevention and control requirements in the performance technical specifications and if necessary, mark up guide specifications (UFGS) with prescriptive requirements (DBB and DB)

  • Include corrosion prevention and control requirements in the Request for Proposal (RFP) (DB)

  • Evaluate Architect Engineers and Contractors' technical proposal with CPC in mind (DBB and DB)

  • Insure corrosion prevention is discussed at the design/construction kick off meeting and implemented on the plans at each submittal stage (DB)

Identifying CPC requirements and selecting the associated criteria to utilize is an essential part of the CPC facilities design challenge. The practical selection, application, and implementation of corrosion-related solutions can be found in the technical manuals, bulletins, maintenance and operations manuals, handbooks, guides, and engineering technical letters, all of which can be found on the WBDG site. This guidance presents a rich and in-depth body of knowledge available for the engineer, architect and construction professional to assess and select the best solution for durability and sustainability. The CPC Training Vignettes also provide in-depth just-in-time corrosion related perspectives.

Construction, QA, QC and Commissioning

Since design occurs after construction award in a DB contract, and in some cases in phases during construction, there are opportunities to ensure that appropriate corrosion prevention and control (CPC) elements are incorporated into the design including the selection of materials and coatings. It is recommended that construction management engineers:

  • Ensure that corrosion prevention is discussed at the design/construction kick off meeting and implemented on the plans at each submittal stage

  • Ensure that the design component or assembly complies with the requirements from the RFP, including performance technical specifications, referenced UFC, and UFGS

  • Ensure that the design drawings and specifications address corrosion prevention and control through proper choice of materials and coatings

Ensure that any modifications to the original design and specifications do not reduce the corrosion prevention features of the building component including: material substitutions, type, grade, thickness, and coatings, design detail changes to the component or assembly. Also, ensure that deviations, substitutions, and field modifications are approved by the designer of record. Avoid trade-offs of corrosion prevention technologies and features (such as cathodic protection) or elimination of the Operation and Maintenance Support Information (OMSI) in order to obtain project betterments or to offset shortfalls in the construction budget.

The QC Plan should also include specifics related to the CPC aspects of the project including coatings, mold and mildew prevention, steel types, and materials to accomplish the CPC objectives in the design. The submittal plan should include all CPC related materials, treatments and processes. Similarly, the Design Quality Control Plan should include CPC details to ensure that the government can establish the correctness of the design and ultimately the installation of these CPC related features.

Government Quality Assurance (QA) should consider all of the above and select the most critical systems for oversight to ensure contractor compliance with the Request for Proposal and associated design. A good example of QA is in the NAVFAC ECB 2008-03; these guidelines highlight several CPC related areas outlining acceptance testing guidelines for government engineers. More importantly, a QA Plan focused on CPC provides the government with the verification that it has actually received what has been identified in the contract.

As defined by ASHRAE Standard 202-2013, The Commissioning Process for Buildings and Systems, and ASHRAE Guideline 0, commissioning can be defined as:

"A quality-focused process for enhancing the delivery of a project. The process focuses upon verifying and documenting that all of the commissioned systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the Owner's Project Requirements." For additional information follow this link on the WBDG for commissioning as well as the Building Information Modeling (BIM) content area.

One important action is critical as it relates to CPC - during turnover from the construction agent to the installation responsible for sustainment, key documents that include information on the built facility (e.g. as-built drawings, HVAC balance and equipment operation test results, material types (coatings, cathodic protection), equipment descriptions and operations, manuals, warranties, etc.) along with commissioning information must be transferred to the SRM manager. This is typically referred to as Operations and Maintenance Support Information "OMSI" and is usually electronic. This information is key to successful SRM management.

Consider that while all oversight activities should catch most errors and oversights, understand that the adages — "you do not know what you do not know," and "if you have not seen it before you will not know what you are seeing" — are not a good combination for engineers, architects, contracting officer representatives, inspectors, contractors and construction personnel tasked with these responsibilities. Every effort should be made to utilize qualified professionals! See CPC Competencies.

Design and Construction Best Practices and Lessons Learned

Photo of the U.S. Navy Hospital in Guam. Opened 2014.

Photo of the U.S. Navy Hospital in Guam. Opened 2014. Photo credit: U.S. Navy Jesse Leon Guerro/Released

Design best practice decisions for the new Guam Navy Hospital, completed in April 2014, incorporated a combination of local knowledge of the extreme environmental severity conditions with WBDG criteria to produce a durable facility. These best practices included:

  • Higher quality concrete (impervious to water/chloride intrusion) helping mitigate corrosion of the reinforcing steel and concrete
  • Concrete with silica fume, fly ash
  • Low water-to-cement ratio
  • Use of aggregates that inhibit the alkali-silica reaction preventing premature degradation of the concrete
  • Use of galvanized steel, stainless steel, and non-metallic components and appurtenances providing better corrosion resistance than carbon steel
  • Aluminum or stainless-steel doors and windows in lieu of coated carbon steel for better corrosion resistance
  • Galvanized steel, stainless steel, and aluminum hardware were also used in lieu of carbon steel
  • Isolation of dissimilar metals using dielectric inserts or protective coatings after proper surface preparation helping prevent galvanic corrosion

Here is a broader list of best practices applicable to DoD facilities across the environmental severity spectrum.

Design and Construction

  • Ensure that personnel engaged in CPC decision-making activities, such as acquisition, design, inspection, maintenance, and repair, have appropriate training and qualifications. See the Training page and the Competencies page for a more extensive list of insights

  • Ensure that CPC features or requirements are included in project and construction documentation such as the request for proposal, associated designs and criteria documents, and Contractor Quality Control, Quality Assurance and Commissioning Plans regardless of the size and type of procurement

  • Poor construction practices can easily negate the best design provisions to produce a durable and corrosion-resistant structure

Design

  • In unique areas, like Alaska, compare local design codes and regulations to the main UFC to account for snow and wind loads or other environmental challenges

  • Ensure that funding is sufficient to include CPC materials and coatings that are life cycle cost effective, appropriate for the environment where the project is located, and are able to reach the intended service life without extensive preventative or corrective maintenance

  • Record lessons learned into the specifications, change maintenance practices or provide feedback to the design agent. Each (base) champion keeps area specific specifications and details. Perform design reviews specific to trade areas. Perform constructability reviews with single point of contact. This practice includes management, engineering and design and utilities areas

Construction

  • Develop a project notebook, which shows the supplemental specifications the site needs or desires (e.g., compressors, certain types of chillers, building practices that need to be followed to avoid painting and deterioration)

  • Ensure modifications and substitutions to the original design and specifications do not reduce CPC features or increase maintenance requirements

  • Materials degrade at a higher rate once rust forms and chemical deterioration of the material begins; avoid damage to coatings and surfaces; even the most minuscule break in a coating can be a starting point for corrosion; and, a marred or scratched surface becomes anodic to the surrounding metallic surface

  • In addition to energy loss, openings in the building envelope can result in interior corrosion and mold. Chronic moisture intrusion and high humidity levels (greater than 60%) can lead to indoor air quality issues and mold growth both visible and hidden

  • For concrete construction, the quality of concrete and its ability to prevent corrosion is highly dependent on the quality of the mix design and construction activities associated with its placement

  • Resist the temptation to backfill utility trenches partially with in situ soils because of job site shortages of select fill. It is critical to have all soils in contact with the structure or utility to have consistent properties and be of similar composition

  • Ensure that information on CPC features is included in project as-built drawings, operation and maintenance documentation, and other related information

  • Have and utilize a feedback system on contractor performance

Relevant Codes, Standards, and Guidelines

Criteria on the WBDG are generally based on industry standards. An industry standard is an established norm or requirement about technical systems, usually presented in the form of a formal document. It establishes uniform engineering or technical criteria, methods, processes and practices. Industry Standards can also be found in the form of reference specifications. The standards referenced in criteria are usually written and maintained by Standards Organizations. See Code Taxonomy. See the following for additional guidance and information:

WBDG