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.

Now is the perfect time to take us up on our offer for a complimentary inspection – before winter snow and cold impact your concrete. Mike Hubbard, who joined HEXA as Sales Manager last spring, will walk your site with your property manager or mechanical engineer, discuss your issues, and tell you precisely what it will take to resolve them. With expertise built over four decades, Mike knows the concrete industry literally from the ground up and has experience in all aspects of the business.

Mike will help you protect your concrete investment by locating and correcting the actual cause of your damage, not just patching up a symptom. Common issues he’s seeing in recent garage inspections include:

Give us a call to schedule an inspection with Mike. He’ll assess your structure for signs of vulnerability, provide you with a bid, and help you take preventive action or budget for 2022. You can count on the HEXA team – Colorado’s concrete experts – to keep you ahead of the game with a plan for affordable maintenance and repairs.

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 Metro Point 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.

HEXA is currently working on an extensive and interesting repair at the top of the huge atrium at Wells Fargo Bank in Denver, which needs to be resealed. The area apparently started leaking several years ago and was undetected at first. Eventually, the leaks became visible, then progressed to the point that buckets sometimes had to be put down to catch water during heavy rains or snow melts.

This massive project will require cutting out and removing the old, weakened sealant and installing new caulking on all window-to-window joints. It will require at least six months to complete. To give you an idea of the scope of this job, once it’s done, we will have replaced 52,000 linear feet of caulking on 2,900 windows – many of which we can only access by tying ourselves off and using the 14 ladders that are attached to the exterior of the building. No fear of heights here!!

This is a perfect example of the damage Colorado weather can inflict on buildings and why periodic inspections are so critical. When windows have not been checked and resealed at regular intervals, caulking can deteriorate and water leaks can sometimes result in structural damage depending on where they occur. We’d like to offer you a free inspection to make sure your concrete and sealants are sound.

Just another day at the office for HEXA. We wanted to share with you our beautiful view as we are busy inspecting winter and sun damage to window sealants. This is a common issue we’re seeing a lot of these days. If not addressed, it can allow water and chemicals in, which could eventually lead to structural damage and the need for major repairs.

Constant exposure to the elements can lead to sealant failure. No one likes a leaky building. Don’t get stuck with an average fix that leads to future complaints. At HEXA, we’re sealant specialists. We assess windows and use the proper sealants to wet seal any window perimeters that are leaking or will be in the near future.

Exterior repair locations can be difficult to access, but with our expert team and know-how, nothing is out of reach!

As you’ve probably seen in the news, the construction industry as a whole is experiencing a shortage of materials and supplies. We’d like to shed some light on the situation and how your future projects could be affected.

There are multiple reasons for these shortages including a record level of housing starts, raw material depletion, and the pandemic’s impact on both shipping and manufacturing.

We are working hard to stay informed about the availability of materials and to maintain adequate supplies on hand when possible. We are also doing everything we can to keep our prices competitive.

You can stay ahead of the curve by getting in touch now to let us know your expected needs for repairs and new projects so we can plan as far out as possible. If you are not sure of your needs, schedule a free inspection and we can help prioritize the urgent projects.

One thing that we’re sure of in all of this uncertainty, is our commitment to building strong relationships with our customers, a fast response to your needs, and getting your projects done on time according to our quality standards. We value your ongoing business and friendship. Please don’t hesitate to contact us if you have questions.

The really cold snap we recently experienced in the Front Range area was a rude reminder of how brutal winter can be – especially to concrete.

Cold weather damage comes from more than low temps. Concrete is vulnerable to salt, gravel, magnesium chloride and other ice-melting chemicals. Salt can leach through concrete and rust reinforcing rebar and wire mesh, adding to the corrosion that occurs when water seeps through cracks that expand and contract with the freeze/thaw cycle. If concrete is not properly sealed or the sealant is damaged or worn, seepage is an even greater risk and can eventually do damage to supports and other structures below the concrete.

Snowplows stress concrete as well. Especially those that do not use rubber blades can damage coatings. They can also cause damage to expansion joints. Even studded snow tires on passenger vehicles can take a toll, especially at exceptionally low temps when concrete is more dry, brittle, and susceptible to damage.

You can’t stop the cold, but you can repair the damage and prevent it from getting worse. We’ve been maintaining and repairing concrete in Colorado’s Front Range for more than two decades and are experts at dealing with whatever winter throws at it!

Give us a call to schedule a free inspection to assess winter damage to your concrete. We’ll help you plan and budget for repairs and preventive maintenance that will help your concrete stand up to Colorado winters.

Why are our crew members dragging a chain across a concrete surface and striking it with a hammer? We’re checking for delamination, which may be hidden and often can be “heard” before it is seen.

Typically, when metal strikes solid concrete, it produces a clear, ringing sound. But if a dull, drum-like thud or loud clack is heard, there are likely hollow areas in the layers of concrete. Dragging a chain across concrete surfaces and listening for a change in tone helps us find extensive damage that has occurred below the surface due to water intrusion, which can damage the rebar and cause delamination. Striking the concrete with a hammer helps further pinpoint these voids.

Delamination occurs when thin layers of the slab, typically 1/8 to 1/4 inch thick, separate from the base concrete of a finished slab. This problem often occurs if finishing operations start prematurely and close or seal the surface before excess air and water can bleed out of newly poured concrete, creating subsurface voids where air or water was trapped. These voids create weakened zones right below the surface that can eventually detach under use, especially if your concrete is exposed to heavy traffic or wheel loads.

It is important to address signs of delamination early to avoid extensive repairs such as removing and resurfacing the top layers of concrete. Schedule now for an early spring appointment to have your concrete inspected for delamination and other hidden, or not-so-hidden, signs of damage so that you can take preventive action before they become costly repairs.

Winter is coming to Colorado and it’s a tough season for concrete. Water seeps into joints and existing cracks, expanding and contracting with the freeze/thaw cycle, which further damages the concrete. Taking preventive action before the long months of winter can ensure that your vulnerable concrete will have sustained less wear come spring.

In this short video, the HEXA crew is scraping away the existing coating and sealants on the island areas of a parking structure. The islands were weathered, which had allowed water to seep in and had started breaking down the concrete. Once the old finish was removed, we installed new urethane sealants, a cementitious coating, and a clear, penetrating sealer. Had we not addressed these issues additional water could have intruded, potentially deteriorating the parking structure underneath.

By being observant of the condition of their concrete and taking proactive steps when they suspected damage, the client has protected themselves from future repairs, expense, and possible liability.

Our free inspection can help you do the same — give us a call today!

HEXA is working hard to make your properties work better for you! Our expert crews recently made some repairs and installed a new pedestrian coating on five balconies at a property in Denver. This short video shows some of the work.

Concrete damage is common in Colorado. It occurs when water intrudes into concrete joints and cracks then freezes and expands, which can cause the existing coating to fail. For this project, water began leaking into the interior of the building due to the compromised coating. The fixes included removing the deteriorated coating, repairing and replacing the damaged concrete, and then installing a brand-new pedestrian coating for a final seal and finish.

Had these issues not been addressed, water would have continued to leak into the building, creating damage to the interior and the need for costly repairs. You can stay ahead of potential damage and unnecessary expense! Watch for evidence of concrete spalling – round or oval depressions on surfaces or along joints, damaged ceiling tiles, and leaking around interior windows.

We offer complimentary inspections of your concrete. We’ll help you identify issues and allow you to plan for preventive maintenance or repairs before winter weather takes a bigger toll – not only on your concrete but on your wallet. Give us a call today to get on the schedule!