Precast Inc. - March/April 2008 - (Page 10)

TECHNICAL Concrete Repairs What to do when things don’t turn out perfectly. By Evan Gurley Perfect: “Being complete of its kind and without defect or blemish.” E ven the most experienced precaster who follows all the proper mix design procedures and production steps cannot produce a “perfect” piece every time. This is true in most every industry, not just in precast concrete manufacturing. Repair is therefore an inevitable part of most every industry. When something doesn’t turn out perfectly, the imperative question is this: When a correction or repair is needed, what appropriate action should be taken? The answer should be in two parts: one to address the cause of the problem, and one to address the problem itself. needed, ability to accomplish it correctly, available time to properly complete the repair, and cost comparisons of repair versus replacement. Consider these questions: 1. Is it possible to repair the product without compromising the effective structural life, performance and integrity of the product? 2. Will the cost of repairing the product exceed the cost of casting an entirely new replacement? 3. Will the repaired concrete product meet the aesthetic expectations? 4. Will the time constraints allow for proper analysis and an appropriate repair? 5. If you were purchasing this product for your project, would you be satisfied with the quality of the product? 6. Will this repaired product upon delivery impact your company’s relationship with the buyer and negatively influence future work? What cost do you put on that? After you have considered these questions and decide that repair is the best alternative, step through your standard repair procedure. If you don’t have a standard repair procedure in place, you are probably not alone – but it’s a good idea to develop one. Here is a synopsis of what a standard repair procedure may contain: 1. Determine what is causing the problem. 2. Evaluate the severity of damage (classification, major/minor). 3. Determine your repair method. 4. Prepare older concrete for repair. 5. Apply repair to the product. 6. Allow for proper curing of the repair. 7. Inspect the repaired concrete. 8. Establish a database of files for repaired products and document repairs. With a standard repair procedure, you can consistently evaluate concrete repairs on a case-by-case basis. It can be used for major as well as minor defects. It is also highly recommended that you have an up-to-date concrete repair manual. Major or minor? Determining whether the defect is classified as major or minor is your next step in the repair procedure. A qualified person should judge which defects are minor and which are major. This person must be thoroughly familiar with the product’s function and the environment in which it will exist. The classifications of major and minor defects are stated in the NPCA 2008 Quality Control Manual for Precast Concrete Plants: Minor Defects. “Defects not impairing the functional use or expected life of a precast concrete product shall be considered minor defects. Minor defects may be repaired by any method that does not impair the product. Repairs of minor defects are essentially cosmetic; in other words, the product would behave as intended without the repairs.” Major Defects. “Defects in precast concrete products that impair the functional use or the expected life of products shall be considered major defects. Unless major defects are Get to the root of the problem It is almost always obvious to the naked eye when a problem is occurring with your concrete structure. Cracking and honeycombing, for example, are easy to spot. But the real concern is the underlying cause of the problem. Recognizing that a problem exists is not the same as determining its cause. For example, cracking is seen as a problem, but the cause of the cracking (improper design, improper stripping/storage, drying shrinkage) will require a more in-depth analysis of the structure. Before attempting any repairs, identify the cause and take corrective measures at the appropriate stage of production. This will increase the likelihood that the problem will not occur again. Once you have found and fixed the cause of the problem, it’s time to turn your attention to the problem itself. The bottom line is to determine whether to repair the piece or scrap it, but this requires intelligent evaluation of the cause and severity of the problem, type of repair 10 MARCH/APRIL 2008 | PRECAST INC.

Table of Contents Feed for the Digital Edition of Precast Inc. - March/April 2008

Precast Inc. - March/April 2008 Contents Technically Speaking Concrete Repairs Return-to-Work Programs Marketing in a New World Building Confidence Risk Management Culture Bloquea La Energia – Es Tu Vida! Lock It Out – It’s Your Life! Fiber Optics in Countertops MCPX Wrap-Up Product Profile People & Products Advertisers Index NPCA Calendar

Precast Inc. - March/April 2008

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