by Donny Morelock / Published Aug 2015
Concrete is one of the most versatile, cost-effective, and long-lasting construction materials in existence. That being said, if left without regular inspection, maintenance, and repair, it can be your building’s biggest nightmare. I believe the biggest misconception with concrete restoration is that it is always a hidden problem and that there is very little preventative maintenance required. This is not the case. A simple $1000 repair left unattended over time can lead to hundreds of thousands in costly repairs.
Remember the inspection and maintenance of your concrete will always cost less than the repair!
Corrosion of reinforcing steel: Steel rebar is protected inside concrete because the concrete is very alkaline, which prevents rust. But if there are chloride ions present, such as from the presence of salt (Florida is surrounded by salt water), the chloride destroys the “passivating layer” of alkalinity around the steel, allowing it to rust. Rust has greater volume than steel and the expansion presses against the concrete putting it in tension and causing it to crack and pop off. Chlorides get to the concrete through cracks or by simply penetrating through the concrete’s pore structure.
To put it in laymen’s terms: The alkaline environment of concrete (pH of 12 to 13) provides steel with corrosion protection. For steel in concrete, the passive corrosion rate is typically 0.1 µm per year. Without the passive film provided by the concrete, the steel would corrode at rates at least 1,000 times higher (ACI222 2001).
Florida, while not having much freeze/thaw effect on concrete, is one of the harshest enviroments on concrete in the country. With our constant high humidity, rain, temperature changes, and salt environment, it can be a perfect storm for concrete issues in your building.
Fun Fact: Here’s how reinforced concrete works: the steel reinforcement is completely useless until the concrete cracks.
My best advice is for you to be proactive more than you are reactive. If you practice this, you will save the owners thousands and thousands of dollars over the years regarding concrete restoration.
Areas of Concern:
In most cases, but not all, the concrete will show signs of deteriation and/or damage that needs to be addressed to include but not limited to the following.
Fun Fact: Florida concrete temperatures can change as much as 25–30 degrees in a day!
This answer is almost always “yes” when it comes to concrete restoration.
Fun Fact: Horizontal concrete is sometimes tested by pulling a “chain” along it, and as the sound changes, it will identify problems in the concrete. On vertical concrete surfaces, I had an engineer in Tampa show me how the use of a golf club can produce the same results.
Author’s Note: Post-tension construction: Post tension is found in many parking garage structures and high-rise buildings and requires contractors specifically experienced with post- tension construction. Make sure your engineer and contractor are members and subscribe to International Concrete Repair Institute (ICRI) specifications. ICRI sets the standards on concrete repair.
Donny Morelock, Owner and President
Concrete Painting and Restoration
Donny Morelock is Owner and President of CPR (Concrete Painting & Restoration) of Tampa Bay and Bradenton/Sarasota, Florida. Morelock brings more than 30 years of business ownership and expertise specializing in customer service in the painting, waterproofing, and restoration field. His motto is “NDC” No Dissatisfied Customers. He believes in offering a great product at a fair price. Morelock and CPR provide a family atmosphere with a blend of accountability. He has served on several charity organization boards in the past and believes in giving back to his community. Contact him at Donny@CPRPainting.net or (727) 939-9393.
Decide how often to have your building inspected
Try to fit the contractor/engineer to the job. If you have a $100,000 problem, then match it with a contractor/engineer who does this size of job. If you have a $3,000,000 problem, then match it to a contractor who has the experience and financial stability to do this size of job. A contractor doing $3,000,000 jobs may not want the $100,000 job.
No one likes surprises when it comes to money going out! If you subscribe to IMR above, you will save thousands of dollars over the years and possibly maintain the sanity of the board and management.