The Hong Kong International airport HKG is home to the world’s busiest cargo gateway airport. In 2015, HKG moved over 4.38 million metric tonnes of air cargo. It is also one of the world’s business passenger airports accommodating over 68 million passengers that same year.
HKG Airport at night
Operations at the world’s busiest cargo airport run 24/7/365 without stopping. Maintenance crews need a crack and joint repair material that can be applied in a wide range of conditions and be ready for service in minutes. Roadware Flexible Cement II is a tough polyurethane crack repair material that can be applied at any ambient temperature. It bonds very well to distressed concrete and forms a tough semi-elastic polymer that will withstand heavy airline traffic in about 15 minutes. Crews at HKG airport have relied on Roadware Flexible Cement II to make repairs whenever and wherever needed for over 5 years.
Maintenance workers repair a taxiway at night with Roadware Flexible Cement II.
Crews use Roadware Flexible Cement II in 600ml cartridges to quickly repair concrete cracks in a taxiway at HKG airport.
HKG crews use Flexible Cement II to seal cracks damp conditions.
Roadware Flexible Cement II™ is semi-ridged polyurethane for creating flexible bonds between concrete surfaces and other materials. This versatile material may also be used to protect contraction joints from traffic deterioration.
What is Flexible Cement II? ProprietaryPolyurethane Blend
Formulation: Classified
Manufacturing: South Saint Paul, Minnesota, USA
Origin: Designed for creating flexible bonds between concrete surfaces and dis-similur materials.
Function: To flow into concrete cracks and joints. Filling the void with a semi-flexible polyurethane the will accommodate heavy traffic.
Military Use: Classified
Civilian Use: Fill cracks, joints and spalls in commercial, industrial and civil applications.
Service Life: Indefinite
Cure Time: 10 Minutes at 70°F (21°C)
Distribution: Worldwide Distributor Network
Exterior Repairs
Use Flexible Cement II™to repair cracks and protect control joints in parking structures, bridge decks, loading docks, and many types of structural concrete.
Control Joints
Use on industrial floors to protect saw-cut control joints from wheel traffic damage.
Cove joints
Use Flexible Cement II™ to seal cove joints where the floor meets a structural wall.
Electrical Podding
Seal electrical loops and embedded lighting systems.
Thresholds
Repair concrete thresholds with high thermal differentials.
Moisture
Flexible Cement II™ is tolerant of surface moisture when applied. Concrete should be as dry as practical to insure a good bond.
Concrete Bonding
Flexible Cement II™ is an excellent flexible adhesive for bonding metal, wood, and synthetic materials to concrete. Use to bond moldings and tack strips to concrete floors.
Bond asphalt to concrete.
Bond wood to concrete.
Bond metal to concrete.
Bond carpet nail strips to concrete.
Bond carpet molding to concrete.
High Traffic
Repairs are tough and can handle heavy industrial traffic.
Use Flexible Cement II™ to protect joints and cracks in concrete bridge decks and pavement where heavy traffic is anticipated. This polyurethane is about as hard as a roller blade wheel and will prevent debris from filling cracks and causing further deterioration of the concrete.
Flexible Cement II™ is recommended for low movement crack repair. This tough material will hold up to forklift and industrial traffic while allowing for some movement. For high movement areas and expansion joints, we recommend a softer caulk type material.
Flexible Cement II™ repairs are ready for traffic in just 10 minute at 75 degrees F (24C).
Bulk mixing Flexible Cement II™:
The passenger tram at this airport gilds on pillows of air. Flexible Cement II is used to prevent the expansion joints from damaging the air pillows.
One of the 12 air pillows that support each car. Flexible Cement II™ prevents metal expansion joints from lifting up and cutting the air pillow as the car passes.
Flexible Cement II™ is used to protect the interface between the metal expansion joint and the concrete. This allows for a smooth surface for the air lift cars to glide over.
Use Flexible Cement II™ to repair sawn contraction joints and cracks
At Roadware, we encounter many two-component polymer concrete repair products that claim to be similar to Concrete Mender™. One product even refers to itself as “Quick Mender.” However, these products are primarily polyurea-based and are often too thick to effectively penetrate concrete surfaces. Additionally, they are highly reactive, becoming sticky and gooey just one or two minutes after mixing, making them difficult to trowel. When you examine the details, you will notice a significant difference between these alternatives and the genuine Roadware 10 Minute Concrete Mender™.
What is Concrete Mender? Proprietary Polyurethane Blend
Formulation: Classified
Manufacturing: South Saint Paul, Minnesota, USA
Origin: NATO program for rapid bomb damage repair on runways.
Function: To penetrate deep into concrete cracks, joints, and spalls, creating a structural repair in 10 minutes.
Military Use: Classified
Civilian Use: Repair cracks, joints, and spalls in commercial, industrial, and civil applications.
Service Life: Indefinite
Cure Time: 10 Minutes at 70°F (21°C)
Distribution: Worldwide Distributor Network
Surface Tension:
Surface tension measures a liquid’s ability to overcome its internal friction and penetrate materials such as concrete. Roadware 10 Minute Concrete Mender™ has a surface tension that is one-third that of water, allowing it to enter concrete cracks and fissures more quickly and deeply than water. This low surface tension enables Concrete Mender™ to infiltrate standard bond lines and promotes structural bonding with the concrete’s aggregate. For more details, please refer to the electron microscope slide below.
Low surface tension offers another hidden benefit: it enables Roadware 10 Minute Concrete Mender™ to be mixed with more than two parts sand while still remaining workable and easy to trowel. In contrast, if you try that with a polyurea, you’ll end up with a gooey mess.
Roadware 10 Minute Concrete Mender can be bucket mixed and applied like or mortar.
Roadware Microdoweling™ Technology:
The slab-to-slab micro-doweling action provided by Roadware 10 Minute Concrete Mender effectively links concrete slabs together, securing them in place while allowing for full traffic and dynamic load transfer within just 10 minutes. This micro-doweling action is more compatible with concrete and less reactive in harsh environments compared to poly-coated rebar. Millions of micro-dowels penetrate the slabs, bridging and bonding broken and jointed surfaces side by side. This remarkable technology is suitable for addressing hairline cracks, wide trench cracks, irregular cracks, cured control joints, and variable depth spalls.
Scanning electron microscope image of the interface between Concrete Mender™ and concrete.
In just 10 minutes at 70°F (21°C), this micro-doweled bond achieves compressive and shear strengths equivalent to those of poured and fully cured concrete. As a result, bond-line failures are now a thing of the past. Furthermore, parallel re-cracking, which is often seen when epoxies cure, is eliminated thanks to Roadware’s micro-doweling technology.
Structural Polyurethane
Roadware 10 Minute Concrete Mender™ is a polyurethane-based material designed to restore the structural integrity and aggregate interlock of distressed concrete. Its low surface tension and low viscosity allow it to penetrate concrete surfaces effectively. The product utilizes cross-linking polymer chains to bond directly to the concrete-aggregate matrix. This bonding action harnesses capillary forces to self-inject polymer chains into the surrounding concrete.
The material is engineered to have a modulus of elasticity that is lower than that of the surrounding concrete, ensuring it does not become brittle over time. Additionally, it can be mixed with manufactured sand to create a polymer concrete that is compatible with Portland Cement Concrete (PCC), enabling effective structural repairs for concrete cracks and spalls.
Advantages– One of the key benefits of this material is its very low surface tension and viscosity, which allows for effective saturation bonding of cracks without significant effort. This characteristic enables the repair process to be straightforward, requiring only minimal preparation, such as removing loose debris from the area before application.
Once applied, if the material is allowed to flow freely to the full depth of the crack, the repair can be classified as structural. To enhance the durability of the repair and prevent issues such as water pooling underneath the slab, it may be advantageous to incorporate manufactured sand or quartz into the mixture. This addition helps to optimize material usage and improve overall stability.
For cracks measuring greater than 0.125 inches in depth, it is recommended to mix the polyurethane with sand at a ratio of two parts sand to one part polyurethane. This not only extends the volume of the repair material but also significantly increases its strength. The inclusion of sand provides the added benefit of aligning the thermal coefficient of expansion of the repair material more closely with that of the surrounding concrete, thereby minimizing the risk of future cracking due to temperature fluctuations.
Another notable advantage of these polyurethanes is their versatility in application temperatures. They can be effectively applied in a wide range of substrate temperatures, making them particularly useful for repairs in freezing conditions and cold storage environments. These materials can even be applied in extremely low temperatures, as low as -20°F (-23°C), ensuring that repairs can be conducted year-round, regardless of weather conditions.
Finally, one of the practical benefits of this repair material is its quick curing time. Typically, repairs will be fully ready to accommodate traffic in approximately 10 minutes when applied at a temperature of 72°F (22°C). This rapid turnaround time minimizes downtime and allows for efficient maintenance of surfaces in both commercial and industrial settings.
Toughness:
Roadware 10 Minute Concrete Mender™ mixed with sand gets about as hard as concrete, yet it’s modulus of elasticity is slightly less than concrete so it will move with the slab, not work against it.
Common uses for 10 Minute Concrete Mender™
Spalled control joints and cracks.
Spalls and holes.
Delamination Repair
Uneven slabs and thresholds.
Crack Injection using gravity:
Typical crack injection repair techniques involve epoxy, ports, pumps, and pressure to force thick epoxies into a crack. Roadware 10 Minute Concrete Mender™ with its low surface tension can do same job in less time, less mess, and better performance.
Easy Floor Crack Injection using cartridges:
Roadware 10 Minute Concrete Mender can be injected into a wide range cracks and delaminations using a simple cartridge and special Soft-tip injection mixers. Successful full-depth repairs have been made in 24″ of concrete.
Slowly injecting Roadware 10 Minute Concrete Mender into 24″ of concrete using 600ml cartridge and soft-tip injection mixers.
The core sample shows full depth repair down 24 inches.
Hairline cracks repaired using Roadware 10 Minute Concrete Mender and Easy Injection application.
Vertical Crack injection
For fast and easy vertical crack injection on walls and structures, we recommend the Gebbie Tech System
THE GEBBIE TECH SYSTEM TRANSFORMS VERTICAL CONCRETE WALL REPAIR
Comprehensive testing by Opus International Consultants – repairs have consistently achieved results higher than the manufactured panel.
Full training in the system – a step by step training video and instructional booklet is included within each kit.
Save time and money! Conventional repair methods with epoxy have longer repair times, additional downtime and are more expensive.
Use a hand gun – no need for expensive pumps! The Gebbie Tech System uses the cost effective Roadware 10-Minute Concrete Mender™ hand gun to repair walls.
Complete penetration. Due to the composition of the Roadware 10-Minute Concrete Mender™ the resin travels easily from the injection point.
The approved vertical wall repair system. The Gebbie Tech System is listed in Roadware’s 10 Minute Mender Concrete Data Sheet as the approved method of vertical concrete wall repair.
Repairs cracks from a hairline through to quarter inch. Walls are repaired within 2 – 12 hours depending on the temperature, and the length of the cracks.
Polishable:
Polishing your floor to a mirror like finish? Repairs made with Roadware 10 Minute Concrete Mender™ will not smear into the surrounding surface or gum-up diamond polishing pads. You can even add natural sand to match the grain and color of the surrounding concrete.
Polished concrete repair with Concrete Mender™ Off-white.
The repair pictured above shows Roadware Concrete Mender™ Off-white blended with plain concrete sand and a small amount of portland cement. This water-thin polyurethane is almost translucent. When we add nearly any type of dry sand or aggregate, we get a fast-curing polishable repair that blends beautifully with the surrounding concrete. Since this material is almost translucent, it resists shadowing effects due to over-banding when applied.
Lower Cost:
By adding two parts silica or quartz sand to a gallon of Concrete Mender™ you will yield about 2.2 gallons of repair material.
A gallon of polyurea or epoxy will yield a gallon of repair material. That makes polyurea more expensive to use even at half the material cost! This does not even factor in the hidden costs of short repair life, damage to the surrounding concrete caused by pre-mature failure, or the cost of redoing the repairs when they fail.
4030 Grit manufactured quartz sand is the standard sand used with Roadware 10 Minute Concrete Mender.
Packaging:
Roadware 10 Minute Concrete Mender™ hand packed with state-of-the-art packaging materials. They have to be good. The very low viscosity and surface tension require it.
Bulk Application:
Due to the the extended working time formula, bulk mixing of Concrete Mender™ is easy. Unlike polyureas that start to gel up instantly, Concrete Mender will remain workable and flowable for several minutes before curing begins. Much less wasted product setting up in buckets.
Roadware 10 Minute Concrete Mender can be easily mixed in a bucket with sand or used neat. No pumps of special equipment needed.
Pin-point Application:
With a Roadware needle tip mixer, you can apply Concrete Mender™ within-point accuracy delivering product to where it is needed most. Our needles come as small as 1.2mm in diameter. If you can get a finger nail in the crack, we can get some Concrete Mender in there as well.
Use Roadware needle tip injection to repair hairline cracks in concrete floors.
Freezers:
Working in the cold? We’re from Minnesota. We know first hand what it takes to work in freezing temperatures. Roadware 10 Minute Concrete Mender™ can be applied at temperatures below -30 F ( -34C). That is really cold. Exposed flesh will freeze in seconds. That is almost too cold to go ice fishing. Most repair products would freeze solid before curing and quickly fail. Roadware 10 Minute Concrete Mender™ generates its own heat. Curing will take several hours, but you will still get the same great performance.
Colors:
Roadware Concrete Mender™ comes in two standard colors. Concrete Grey and natural off-white. Since a typical repair is made up of two parts sand to one part liquid, the color of the sand will determine the color of the finished repair. By adding colored quartz sand to off-white Concrete Mender, you can make custom colors as needed.
Use Concrete Mender Off-white to make your own colored repair by adding different colored sand at the time of application.
Specialty Applications:
We also custom make Concrete Mender in Safety Yellow, Red, Blue, and Black. Use Concrete Mender Yellow to create permanent safety lines and marks in difficult areas like cooler and freezer floors.
Safety:
Roadware 10 Minute Concrete Mender™ is completely self-reacting and does not out-gas solvents or VOC’s when curing. This material meets FSIS guidelines for work is federally inspected meat and poultry plants.
History:
For over twenty years, Roadware 10 Minute Concrete Mender™ has performed without fail in thousands of applications. Many times outliving the facility itself.
Supervalue warehouse cold storage floor repairs with Concrete Mender™.
Concrete Mender repair in a cold storage warehouse after 15 years of heavy forklift traffic.
Utilizing technology developed to repair bomb damaged runways for NATO, Roadware 10 Minute Concrete Mender™ was reformulated and brought to commercial markets in the early 1990’s. You can find us in nearly every industry that has concrete floors, decks, slabs or surfaces.
Roadware 10 Minute Concrete Mender is made in the USA and is available from Roadware authorized distributors and dealers worldwide. Call 1-800-522-7623 or 1-651-457-6122 to find a dealer near you.
From the Roadware Crackrepair Fax Newsletter August 17, 2004
Tricks of the Trade
Hereʼs one you can warm up to. While installing 14 cases of Roadware Flexible Cement II (thatʼs 168 tubes), Roadware contractor Dave Wilson got tired of shaking and turning tubes, waiting for the ball bearings to start clicking. Dave headed over to a Super Wal-Mart looking for an electric blanket. It was the wrong time of the year, but they did have heating pads.
Dave had this crazy idea if they warmed up the cartridges, the material would mix immediately, speeding up the installation and keeping the installation virtually striation clear. To make a long story short, he got that and a whole lot more.
The heating pads exactly fit the boxes of Flexible Cement II™..
Open the bottom of the box, remove the bubble packing and insert a heating pad.
Open the top and place an additional heating pad on top of the cartridges.
Turn the pads on to medium/medium high.
Wait 15 minutes.
Take out a layer of cartridges (3) and place the pad on the next layer.
Shake the three cartridges until the white side has a consistent color. You will hear the steel ball rattle inside. Set up the three cartridges and run out 10-15 feet of expansion joint or construction joint with FLEX II.
Have second crew member follow behind with a second application and a third crew member follow with a third application.
At the end of the third application leave the nozzle stuck in the joint to dam the warmed FLEX II.
Set up three more cartridges and continue the run until complete.
The warmed FLEX II will self level, require no additional trowel work and if done carefully, no clean-up needed. Pull the nozzle-dam and replace it with FLEX II as you start the next run. This will eliminate cold joints.
When breaking for lunch, reduce pad heat to medium.
Dave’s Comments: “Iʼve never heard the ball bearings rattle before, but I hear them now. This puts cartridge applications on a par with bulk-mixed FLEX II. Itʼs quick, easy and very effective. The material thins to Mender-like viscosity and penetrates joint walls securing the FLEX II and the joint. The pads may be reused, of course, and the set-up cost is minimal.”
“I highly recommend you try it. It sure worked well on this job and we will continue to use a little heat to keep things flowing.”
Roadwareʼs Comments: “Why didnʼt we think of that?”
Electric heating pads are a good way to warm up Flexible Cement II prior to application. Use caution not to “cook” your cartridges for more than 12 hours. Leaking at the seals may be the result.
