by Joseph C. Dean, P.E. for the Director, Corrosion Policy & Oversight (DCPO), (DASD) [Materiel Readiness]
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 Facilities Corrosion Impacts on Operations and Mission 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 1-200-01 DoD Building Code and the Corrosion Toolbox) 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 good design, construction and sustainment practices, understanding regional or environmental severity influences, and leveraging the associated knowledge of facility requirements to achieve a successful solution.
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 Facilities Corrosion Impacts on Operations and Mission provides additional insights into risks and other factors affecting corrosion related design and construction. 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
- Ensure integrity of building envelope design (UFC 3-101-01 Architecture)
- 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)
Ensure 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)
Ensure corrosion prevention is discussed at the initial design charette and implemented on the plans and specifications at each submittal stage (DBB)
Ensure 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)
- Ensure 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 Modules 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 approved design. A good QA Plan should highlight CPC related areas outlining acceptance testing guidelines for government engineers and will assist with the verification that what has been identified in the contract has been received.
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 Construction-Operations Building Information Exchange (COBie) content area. The later will help place in context the process of characterizing data to ensure that it can be managed to effectively extend the life cycle of a facility.
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
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
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
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
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:
- Federal Facility Criteria—Extensive electronic library of construction guide specifications, manuals, standards and many other essential criteria documents
- Unified Facilities Criteria—Master list of UFCs
- Unified Facilities Guide Specifications—Master list of UFGSs
- Unified Master Reference List (UMRL)—Lists publications/Industry criteria referenced in UFGSs
- CPC Source Criteria