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Don’t Let Post-Tension Repairs Become a Stressor

Post-Tensioning is one of HEXA’s specialties and a technique in which we have certification through the Post-Tensioning Institute. Our recent Post-tension Repair blog explained our post-tensioning work at a Denver Metropoint parking garage. Because of our expertise in Colorado post-tension repair, we’ve received inquiries and interest in the techniques involved, so we’d like to share some additional information about this versatile method of reinforcing concrete.

A Unique Structural System

Post-tensioning is often an excellent choice for Colorado’s weather and is used in many types of structures. It is an especially effective technique for reinforcing concrete in parking structures and garages. According to the Post-Tensioning Institute, “Post-tensioned concrete provides a structurally efficient, reliable, and cost-efficient solution” for concrete parking garages.

Cast-in-place, post-tensioned concrete has become the system of choice for parking operators, commercial building owners, universities, hospitals, and public institutions for a number of reasons:

  • Post-tensioned structural systems often provide initial cost savings and better life-cycle costs, compared to other framing systems.
  • Since they are more water-tight and resistant to cracking, they typically have fewer maintenance issues.
  • Wide beam spacing and the flat surfaces provided by post-tensioning enhance lighting which improves security, provide a more welcoming environment, and a superior riding surface.
  • The slab thickness and beam widths in post-tensioned structures result in long spans which allow for versatility and adaptability to other structural components such as slopes to drains, ramps, irregular plan layouts, and cost-effective architectural treatments.
  • Post-tensioning provides outstanding structural integrity, including under abnormal and catastrophic loading. This means reduced vibration and resistance to wind, which can be important in our Colorado climate.
  • Post-tensioned concrete is not poured as deep as in other techniques so there is less drying time required, which can also be important during some seasons in Colorado. This technique can also reduce structural depths, excavation, and soil retention costs.

Considerations

Although post-tensioned structures typically have better track records when it comes to maintenance, they are complex systems that are subject to some specific vulnerabilities, especially when initial installation was less than ideal. Identifying and correcting problems requires special investigation and repair expertise and techniques.

Problems that can occur include corrosion and cracking of sheathed, steel cables. In grouted structures, improper installation of grout can leave voids and residual moisture which can lead to damage and deterioration. Post-tensioned steel is also more susceptible to damage from chloride-induced pitting corrosion, hydrogen embrittlement, and stress corrosion cracking. Tendon damage can occur and, although there may be external signs of distress, specific inspection methods may be required to find or confirm damage. For example, we use special techniques to evaluate corrosion inside sheathed cables.

Trust the Experts

HEXA’s crews are certified in post-tension repair. We are equipped to get the repairs done right, including taking steps to prevent problems from occurring again.  When you can’t afford to gamble with the integrity of and investment in your concrete, contact us. We’ll perform a complementary inspection and our post-tension experts will take the stress out of your repair work. Check out our Post-Tension Repair brochure here.

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Post-Tension Repair: A HEXA Specialty

Post tensioning is used instead of traditional rebar in applications where it’s especially important to reduce concrete shrinkage or eliminate cracking. This method of strengthening concrete is a good choice in a variety of applications. We’ve recently been doing post-tension repairs in a parking garage at Metropoint in Denver to restore strength to concrete and thought we’d share a little about the process.

Post tensioning uses steel cables – referred to as post-tensioning tendons – inside plastic ducts or sleeves that are positioned in the forms before concrete is poured. Once the concrete has gained strength, but before it has to support service loads, the cables are pulled tight – or tensioned – then are anchored against the outer edges of the concrete.

If post-tensioning components become weakened or damaged due to water intrusion, we remove the concrete to expose the deteriorating tendons. We then install new hardware and tendons and re-stress the cables before replacing the concrete. Finally, we waterproof the new concrete to maintain its integrity and prevent damage to the post-tensioning cables, which can be especially vulnerable to Colorado weather.

Repairing or altering post-tension cables is one of HEXA’s specialties. To discuss restoring the strength of your concrete for years to come, call the HEXA experts today. Check out our Post-Tension Repair brochure here.

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The Best Fix for Horizontal Concrete Surfaces

Can you waterproof flat concrete surfaces?

YES! And in Colorado weather, horizontal waterproofing is a must.

Plazas, parking decks, rooftop terraces, and balconies in Colorado face a multitude of stressors. They all need waterproofing that can withstand exposure to wide temperature swings, frequent freeze/melt cycles, strong UV rays, salt and de-icing chemicals, and heavy traffic – all while looking good.

Products used for above-grade waterproofing differ substantially from their below-grade counterparts. A structure with no flashings, no sealants, and no membranes on the roof and walls would last only a few years. These above-grade concrete surfaces also need to resist abrasion and corrosion.

What is Horizontal Waterproofing?
Horizontal waterproofing applies a thin layer (generally between 60 to 120 mils) of continuous water-tight material over a surface. For example, on a flat terrace, horizontal waterproofing is applied above the structural slab and below the finish tiles at a sloped angle to ensure there is not standing water or seepage.

To give you a long-term fix and put an end to your surface water damage, the expert HEXA team uses two types of horizontal waterproofing applications: liquid applied membranes and sheet-good membranes. We use only the highest quality of materials for a strong, flexible, tear-resistant product that stretches over cracks, flexibly takes the shape of what it covers, and resists our harsh Colorado weather. 

  1. Sheet-good Horizontal Waterproofing
    HEXA’s sheet-good waterproofing provides continuous, consistent thickness and strong adhesion to bond tightly with your surface and ensure water does not seep into the structural slab.
  1. Liquid Horizontal Waterproofing
    We spray or brush-on our liquid waterproofing and can thereby regulate the thickness as needed. The procedure is very fast and air cures the liquid into a seamless, joint-free membrane.

Protect the Investment in Your Building’s Exteriors.
Now’s the time to spruce up your building for Spring! With HEXA’s fast, quality repairs, your outdoor spaces will be back to looking beautiful and professional in no time.

Contact us today and we’ll find the best solution to end your puddles, pooling, and concrete damage once and for all!

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Winter Cracks Can Break the Bank

Colorado winters are tough on concrete. When water turns to ice it expands about 9%. If that water has settled into even a hairline crack, it can mean big damage when the temperatures drop.

Whether it’s in a parking structure, concrete slab, or foundation wall, damage can occur with the first freeze-thaw cycle and will worsen exponentially with every cycle.

Hidden & Visible Concrete Distress
There are many ways concrete is stressed in these winter months. Some damage is visible and other damage occurs below the surface. You may experience:

  • Enlarged and new cracks in your concrete
  • Water damage in your building
  • Plastic shrinkage creates cracks typically two to four inches deep and 1/8” wide on horizontal surfaces exposed to the atmosphere. These cracks can form in cold weather conditions when the temperature of the concrete is high compared with the surrounding air temperature. The concrete dries, shrinks, and cracks due to rapid moisture loss.
  • Scaling (sometimes called mortar flaking) is visual or microscopic flaking or peeling of a finished, hardened, concrete surface created by hydraulic pressures from repeated freeze-thaw cycles within the concrete. The expansive forces caused by the ice are exacerbated with deicing chemicals which increase saturation and the number of freeze-thaw cycles.
  • Spalling is when surfaces peel, pop out or flake off due to water entering the concrete.
  • Popout is a cone-shaped fragment of concrete caused when winter moisture freezes and expands, creating internal pressure that ruptures the aggregate surface.
  • Popoff is an exposed coarse aggregate particle that is caused by pressure buildup when the moisture in the mortar above the aggregate freezes. This is usually the result of poor quality concrete mixtures, improper finishing or inadequate curing. Deicing salts may aggravate this issue.

How You Can Prevent Problems
Preventive care for your concrete is important any time of the year, but it is especially vital during the winter months. Don’t wait until you can see big problems.

Save money and increase the lifespan of your Colorado property with HEXA’s concrete repair services.  On a regular schedule, our concrete experts will identify and repair what seem to be innocent cracks before they can do more damage.

Contact us today to let us know how we can help prevent problems tomorrow!

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Reasons to Hire Our Commercial Concrete Contractor

Concrete repair firms literally lay the foundation for property owners and managers. That said, not all commercial concrete contractors provide the same quality of work and variety of services. Of course, hiring the wrong team could leave your company in hot water. So what exactly makes HEXA (formerly McDonald Waterproofing and Restoration) so different? Here are the top five reasons why you should consider hiring our concrete specialists:

 

  1. Honesty – This is an industry where clients are often taken advantage of because they simply don’t know much about concrete. Here at HEXA, we believe in transparency from the time you first call us to the moment the project is completed. Have a number of questions along the way? You can count on us to provide honest, thoughtful responses.
  2. Respect – The unfortunate reality is that many concrete restoration companies don’t even give their clients the time of day. That’s not how we conduct business, though. Locally owned and operated since 1999, we don’t just see clients as another number in the project queue. Rather, we see them as our neighbors and family in the Mile High City.
  3. Quality – Many competitors in the industry settle for short-term fixes because they’re often the easiest approach. However, we have found over the years that these “band-aid” strategies fail miserably down the road. At HEXA, we do concrete repair the right way. What do we mean by this? Well, by understanding the dynamics and conditions of concrete, we can apply the best technology and building methods. Never will we use a “cookie-cutter” or “one-size-fits-all” approach to your project. Our job is to provide clients with concrete services that deliver an unmatched return on investment.
  4. Versatility – Some concrete and waterproofing companies offer a few select services and that’s it. HEXA is the one-stop shop for concrete repair. Could your commercial space benefit from concrete strengthening with carbon fiber systems and engineered steel bracing? We can customize a solution to fit the needs of your project. Have you noticed minor cracks around on your property as of late? Rather than sit back and wait for those small cracks to turn into major issues, ask our experienced team about concrete crack repair using urethane grout injection and epoxy injection.
  5. Communication – Wouldn’t it be nice if you could get a quick snapshot of the project status, whether you were on-site or thousands of miles away? We make that possible at HEXA thanks to our innovative Daily Project E-report. Take a look at the number of personnel on the project, morning and afternoon surface temperatures, amount of work completed, and upcoming tasks. We are proud to be the only contractor in the region who utilizes such a system. With such an emphasis on constant communication, you can say goodbye to frustration and delays while waiting for the project to be finished.

When it comes to reinforcing concrete solutions, HEXA (formerly McDonald Waterproofing and Restoration) has you covered. Get in touch with us today to get started.  

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Myths in Concrete Construction

There are a number of misconceptions out there when it comes to concrete construction. Some concrete strengthening companies cut corners while others fail to use the latest techniques and top-of-the-line technology. There’s no question that you want the project done right the first time. That said, let’s debunk some of the most common industry myths.

  1. Concrete is impermeable – Here’s the deal: even the most dense concrete is somewhat porous. It can take anywhere from a few minutes to a few months for water and other substances to pass through concrete. You just never really know. To combat the issue, a company may choose a combination of chemical admixtures, as well as surface treatments such as sealers and membranes.
  2. Concrete’s strength and durability go hand in hand – Not necessarily. Concrete generally deteriorates because of corrosion of reinforcing steel, exposure to freeze-thaw cycles, and sulfate attack, among other natural events. It’s important to know that the key to durability is reducing permeability.
  3. Concrete can be placed on frozen ground without any issue – This is a topic of conversation in many areas, but especially in Colorado. The short answer is that precautions must be taken to protect concrete in less than ideal conditions and prevent future soil problems. Simply put, concrete placed on a frozen subgrade may settle unevenly when the subgrade thaws. Not surprisingly, this leads to cracking.
  4. Concrete that is flat and level after placing will always remain flat and level – Unfortunately, this isn’t factual either. The truth is that concrete will change in volume while setting, hardening, and drying. Slab edges that curl come about from differences in the moisture content and temperature at the top and bottom of the slab.
  5. Reinforced concrete won’t crack – Most people don’t realize that structural reinforcement is meant to hold the cracked areas together. As explained on Concrete Construction, “When concrete cracks, the tensile stress is transferred from the concrete to the steel.” This is what allows reinforced concrete to hold up against higher tensile loads than concrete alone.          

Reinforcing Concrete Solutions

Is your commercial space in need of concrete restoration? If so, you need to find a reliable company that can handle the project. HEXA has been serving the Denver metro area for more than two decades. What makes our team different is that we focus on delivering long lasting solutions in the most cost-effective manner. Never will we use a “one-size-fits-all” or “band-aid” approach.

Today, HEXA ranks as one of the top specialty repair contractors in the state. You can count on us to do everything from concrete replacement to concrete crack repair and everything in between. We aren’t about treating your project like a number, either. Our staff takes great pride in client satisfaction and our innovative communication process.

We understand how intimidating concrete repair can be. Not to worry, though. We try to keep things simple and walk you through the entire process. At HEXA, honesty, friendliness, and quality are always top of mind.

Don’t be tricked into believing any of these or other concrete construction myths. Contact us today to get started with your project.

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