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Maintaining Structural Integrity

Integrating a solid concrete repair strategy into your facility alleviates maintenance issues and contamination Lee Popovich & Bob Hall, Structural Preservation Systems, Inc. Burdened with the responsibility of balancing production, worker safety and demanding cost-saving measures, managers of food processing facilities are left with little time to protect and maintain the structural integrity of their plants.

Integrating a solid concrete repair strategy into your facility alleviates maintenance issues and contamination

Burdened with the responsibility of balancing production, worker safety and demanding cost-saving measures, managers of food processing facilities are left with little time to protect and maintain the structural integrity of their plants. In fact, facility maintenance budgets -- typically funded for equipment and capital needs with little room for actual maintenance programs -- are sometimes given such a low priority, deterioration occurs to the point where the plant process is impacted. Left ignored and exposed to a host of variables, concrete problems are likely and often result in downtime or the drastic effects of spoilage. However, integration of a concrete maintenance and repair program that addresses the specific needs and use of each facility is money well spent as facilites benefit from an extended service life, no process loss, as well as a significant reduction in contamination.


Controlling the Money Pit

Over the course of the next few years, food processing plant managers will spend millions of dollars on plant infrastructure and repairs that generate little to no revenue return. While integration of new equipment or a plant expansion may add to the bottom-line, maintenance and repair of concrete foundations and flooring is often overlooked or ignored since it "produces" no revenue. However, such neglect is dangerous because concrete requires preventive maintenance, just like machinery and equipment. Although the process of deterioration or damage often takes years to manifest itself, the damage is exponential and irreversible once the "fuse is lit" - worsening as time progresses - thereby developing into more expensive and extensive repairs. It is a classic "pay now...or pay a lot more later" situation for plant managers, who need to keep an eye on both short-term and long-term expenditures.

Because of the nature of food processing facilities, concrete deterioration from process operations is a continual maintenance issue. A range of factors - to include initial design, quality control, construction practices and facility upgrades or changes in the use of equipment -- work to shorten the service life of concrete within food processing operations. Such factors have proven to be detrimental to the concrete/coating or lining system, thus causing water damage, cracking and spalling. Further, man-made forces -- such as impact, overloading and chemical attacks by aggressive products such as sugars and animal fats -- are common contributing factors. A small crack in a protective lining invites intrusion by moisture or corrosive agents. Eventually and inevitably, the outward symptoms of scaling, cracking, delamination and spalling appear.


Concrete Problems are a Real Threat

In the food processing environment, reinforced concrete floors often face the problem of corroding reinforcing steel (rebar), which ultimately leads to concrete spalling and deterioration. And, though many instances of decay occur out of day-to-day sight, concrete delamination is a threat that food processing plant owners and management teams cannot afford to ignore. Moisture in general creates a destructive environment for concrete. When the rebar oxidizes, the oxide - rust - takes up more space than the original steel. The result is pressure on the concrete material surrounding the rebar.

The first signs of this distress typically are hairline cracks which occur on the surface of the concrete positioned near the embedded rebar. When concrete is hit with a hammer near the crack, you'll know right away if you have a problem if a hollow sound is heard. Then, as the rust continues to develop over time, the crack will worsen, and eventually pieces of the concrete will begin to break off. Ultimately, structural integrity will be lost, thus greatly reducing the load-carrying capacity of the structure.


There is No Panacea

Concrete construction, repair and rehabilitation is a complicated field and a quick fix or universal solution will likely result merely in a band-aid to the real problem. Key to successful repair is material and contractor selection to ensure a long-term durable solution. The initial step typically involves nondestructive and destructive testing that includes mechanical sounding, ultrasonic testing, surface hardness testing, concrete sample extraction, as well as physical and chemical laboratory testing. The result of these efforts allows experts to locate, qualify and quantify the root causes and extent of any distress or deterioration.

If any visual symptoms of deterioration begin to appear, it's always best to bring in a knowledgeable expert on structural concrete repair to investigate. The visual symptom may be representative of a larger problem, or simply require only minor, cosmetic repair. Regardless, the worst thing to do is ignore or delay an investigation, as this often results in far costlier repairs.

Once a problem is identified, the first step in finding a solution is to evaluate the structural integrity of the area in question. If it turns out that the structure has been compromised, temporary shoring can usually be installed to render the structure safe until a more permanent repair can be scheduled.

The degree of success for a repair project will largely depend on balancing the needs of the facility owner, plus ensuring close coordination between all parties involved in designing and implementing the optimal solution. Because of the nature of today's global marketplace, manufacturing or processing down-time has drastic effects on the bottom-line. As such, a crucial tenant in the design of the concrete repair is to minimize the impact on the process operations. Therefore, a typical repair strategy may integrate a variety of solutions in order to achieve the best results. Determining the most appropriate repair is best accomplished by involving all parties associated with the repair and the facility, to include the engineer, contractor, plant processing manager and the facility owner.


Choosing the Right Materials

Far beyond the simple concrete patch, today's technologies offer a range of solutions for an effective concrete repair program. A basic understanding of these options - surface/structural repair, protection, stabilization, strengthening and waterproofing -- will allow selection of the best program for your facility. A concrete repair specialist can help determine both the underlying cause of the problem and the optimal solution.

Too often, a repair ends up requiring maintenance of its own if proper attention was not given during the material selection process to the following conditions: performance requirements, service and exposure conditions, load-carrying requirements, operating conditions during placement and cure, original cause of the deterioration, concrete placement techniques and characteristics, concrete properties and the materials or systems needed to meet the required objectives. Further, when selecting repair materials, the relationship between time and performance is an integral component.

As in any decision-making process, knowledge is power. "Value-added" services relating to concrete repair should be no different than those provided by equipment suppliers. Education of plant personnel concerning concrete material basics, deterioration mechanisms, repair strategies and construction techniques will enable teams to make better repair strategy decisions and prevent costly repairs.


Creating Long-Term Success

It is never too late to integrate a maintenance program into your facilities plan. Most have found the cost of a yearly maintenance inspection to be nominal compared to the costs of repair and rehabilitation resulting from neglect. Further, with control over infrastructure costs, the plant's operating and financial performance will improve. In addition to cost-savings, early intervention has proven to identify problems that appear to be cosmetic yet could actually impact the safety and productivity of the plant.