By Eric Carlton, P.E.
How comfortable are you having difficult conversations? If you are like most people, these are conversations you try to avoid. Sometimes, though, hard discussions are necessary. And being prepared is the first step toward providing a good solution.
As precast concrete producers, a primary goal of every job is to fabricate finished products that comply with project and material standards. It also is important to meet or even exceed each customer’s expectations in order to retain a market segment.
For precasters, that customer – or “end user” – may be a contractor buying the product. It also could be a project owner who approves the final installation and pays for completed work. Both parties are equally important to satisfy in order to ensure a successful project.
Even when product manufacturing follows regimented quality assurance and quality control programs, imperfections still may occur. It is a precast producer’s responsibility, whenever necessary, to clearly and respectfully educate customers on possible imperfections and viable remedies based on product standards and accepted industry practice.
Understand the issue to quantify and classify the defect
When someone is trying to sway your opinion, who are you more likely to trust – a person who backs up statements with knowledge, data and a viable plan or someone who appears to argue their points as they think of them? Most people, especially in business decisions, prefer the former.
When discussing a precast product and a potentially unacceptable defect or a viable repair remedy, it is imperative for a precast representative to be ready with all facts at hand and a complete plan detailing the repair procedure, products, past successes and previous acceptance.
To reach this end, a precaster must develop, implement and continually improve upon a written product defect analysis that includes defect descriptions, classifications and the decision process concerning whether something can or should be repaired. This document should describe any anomaly that falls outside of the plant’s normal acceptance criteria established by plant management. The criteria may exceed the minimum prescribed product standards (such as those published by ASTM International) or be specific to job-related criteria detailed within project plans and specifications.
These product quality expectations should be communicated clearly to the entire production team. If an issue is identified as exceeding the established limits, then the product defect analysis and elimination plan is implemented. This analysis determines the root cause of the defect and whether it was a one-time production error (e.g., a form latch not closed properly or poor handling of an individual piece in the yard) or a larger production process that may affect a day’s or a week’s production, such as continuous honeycombing or constant tolerance problems.
Regardless of the determined cause – which needs to be immediately addressed and corrected – a product cast with an identified defect must not be shipped. At this point, a decision must be made whether the identified flaw is repairable to meet the project’s requirements or should be scrapped and replaced.
Learn what the product standards say
The question of repairability begins with the applicable product standards and project specifications. Many precast products manufactured by NPCA members require adherence to the respective ASTM standards. Most ASTM standards for these products include provisions to allow for some repair.
For example, ASTM C478, “Standard Specification for Circular Precast Reinforced Concrete Manhole Sections,”1 reads:
- 9.1. Repair of manhole products shall not be prohibited, if necessary, because of imperfections in manufacture or damage during handling, and will be acceptable if, in the opinion of the owner, the repaired products conform to the requirements of this specification.
ASTM C858, “Standard Specification for Underground Precast Concrete Utility Structures,”2 reads:
- 9.1. Precast concrete structures may be repaired. Repairs shall be performed at the direction of the manufacturer in a manner to ensure that the repaired structure conforms to the requirements of this specification.
Similar language in both standards permits a repair if the final repaired product still complies with all specifications. However, notice the difference regarding the “owner” or customer involvement.
Other important concrete standards and codes require owner approval of precast product repairs, such as American Concrete Institute’s ACI 301-20, “Specifications for Concrete Construction.”3 Section 13, “Precast Structural Concrete,” reads:
- 13.2.15. Defective Work—If specified, repair chipped, spalled, or cracked members. Obtain acceptance from Architect/Engineer before making structural repairs. Replace unacceptable members with precast concrete members that comply with requirements.
- 13.3.5(a). Submit request and procedures to repair members. Repairs will be acceptable provided structural adequacy, serviceability, durability, and appearance are not impaired.
The important fact with these provisions is that national standards recognize concrete products do occasionally require repairs that need to be performed properly.
It is important for precast producers to understand expectations prior to bidding. Are repair options available if needed? What is the field inspection acceptance criteria?
Precast products visible after installation often have a higher level of acceptance benchmarks. ACI 301-20, Section 13, “Precast Structural Concrete,” states that patching material and curing methods are not distinguishable from the original concrete at a distance of 20 feet.
For architectural concrete, ensuring that repair processes maintain the visual aesthetic quality of unblemished precast components is an integral part of the preproduction process. ACI 301-20, Section 14, “Precast Architectural Concrete,” reads:
- 126.96.36.199. Sample panels—Unless otherwise specified, before fabricating CA members or architectural precast concrete units, produce and submit at least two sample panels each with an area of at least 16 ft2. Incorporate full-scale details of architectural features, finishes, textures, and transitions.
- 188.8.131.52(a). Locate sample panels where indicated in Contract Documents.
- 184.108.40.206(b). Damage part of an exposed-face surface on two sample panels for each finish, color, and texture, and demonstrate sufficiency of repair techniques proposed for repair of surface damage.
- 220.127.116.11(c). After acceptance of repair technique, maintain one sample panel at manufacturer’s plant and submit one for project site in an undisturbed condition as a standard for visual evaluation of completed Work.
Though this may seem extreme for many buried precast infrastructure products, it may be beneficial to have an example of a standard cementitious material repair or a finished example of an epoxy or a polymer concrete repair product on-hand at the plant. This mock-up could be an important part of a plant tour or even an effective hands-on means to show the expertise, workmanship and quality repair that your plant performs.
However, while most customers will permit repairs as an exception or outlier to the norm, a continuous string of products showing or needing repair without a quick resolution to the root problem will raise questions about production practices and product fitness, often leading to product rejection and future job losses.
Repairable or not?
As mentioned earlier, when a defect is detected and the cause corrected, a decision remains to be made regarding whether the product should be repaired or replaced.
Factors to consider include:
- Restriction by project requirements. Some project specifications flatly deny any repair to a precast item despite considerations of the product application or material standards permitting it. Be aware of these restrictive provisions and account for them accordingly.
- Finances. This is a straightforward comparison between the expense to repair – time, labor and material – versus replacing, including lost opportunity and lost profit.
- Time. Will casting a new product cause problematic project delay to the contractor?
- Risk. Is the precast product application so sensitive or severe that the potential exists for the repair to not meet the service requirements?
- Reputation. Job conditions may allow furnishing a repaired product, but will this hurt your company’s brand in the long run?
In some cases, the project owner will provide clear guidance on what is or is not repairable. Such guidance is provided to department of transportation inspectors with the development of the American Association of State Highway Transportation Officials’ R73-16, “Standard Practice for Evaluation of Precast Concrete Drainage Products.”4
This document was developed by DOTs, consulting engineers and precast industry representatives to provide guidance on acceptance criteria for surface defects such as honeycombing, bug holes and joint distress. The document scope provides insight:
- This standard practice describes the evaluation of precast concrete pipe, box culverts, manholes, and drainage inlets. This standard also describes criteria for acceptable products, repairable products, and the rejection of defective products. All repairs shall conform to the criteria found in this document or to contract documents as applicable.
- This standard practice is applicable to storm water management precast concrete products, manufactured by both the wet cast and dry cast production methods, after curing and prior to installation.
- This standard practice covers the inspection of finished products manufactured per M 86, M 170, M 199, M 206, M 207, M 242, M 259, and M 273; and ASTM C443, C858, C913, C985, C1417, C1433, C1504, and C1577.
Evaluation guidelines are included for the following conditions: cracks, manufacturing defects and damaged ends.
When and how to have the discussion
Ideally, the best time to discuss repair with a customer, inspector or other end user is before you absolutely must talk to them. Early assurance tends to lead toward a more positive outcome. Additionally, developing a strong rapport early on in the project often lends itself to a discussion with less stress later.
Start by requesting to attend the contractor’s preconstruction meeting. This provides an opportunity to meet the entire project construction team.
Offering a plant tour is also an excellent way to bring critical personnel from both sides together. And if your staff has produced written repair protocols or even a helpful mock-up during a repair training session, this is an opportune time to discuss quality repair options should they be needed.
To paraphrase Louis Pasteur, “Luck favors the prepared mind.” With respect to acceptance of precast product repairs, “Success favors the prepared precaster.”
More information on precast concrete repairs can be found at precast.org.
Eric Carleton, P.E., is NPCA’s director of codes and standards.