There is a big problem with control joints or contraction joints. They are the saw cut joints we cut into concrete slabs to control cracking as the concrete cures. The problem is the floor owner typically wants the floor poured, joints cut, joints filled, and building occupied in 60 days or less. Concrete cures hard in typically 28 days, but it continues to shrink and crack for a about a year. The contraction joint that was 1/4″ when it was cut, can almost double in width in that first year leaving the 1/4″ of joint filler a bit short, cracked and generally a mess. The sidewalls of the joint are left unprotected and the joint spalling begins. You can replace all that gummy polyurea or brittle epoxy with Roadware 10 Minute Concrete Mender™ and leave your control joint problem behind.
Use Concrete Mender™ to repair cracks, joints and curling slabs under VCT or tile floors. The permanent performance and 10 minute cure turns this 2 day job into a one day (or one night) job. Keep business running with minimal down time.
For spalled or failed control joints that are reflecting through the tile and the slabs are not curled, clean out the joints with a dust collecting diamond grinder.
Repair the control joints with Roadware 10 Minute Concrete Mender™, grind the surface flush and replace the tile.
For curled and buckled slabs, a major retailer specifies this heavy duty solution. This is the ultimate fix it once and fix it forever repair.
Step 1: Remove VCT, Ceramic, or vinyl floor coverings.
Step 2: Saw cut parallel lines to the crack at a depth of no less than 1.5 inches. Ideally 30% of the slab depth.
Step 3: Chip out the concrete between the saw cuts. Clean the surface well with a wire brush and vacuum.
Step 4: Add Roadware 10 Minute Concrete Mender and Sand to the finished grade. Also use Concrete Mender to repair the underlaying crack. See Concrete Mender™ Bulk Application Instructions.
Step 5: Replace the floor treatment and open to store traffic.
Roadware 10 Minute Concrete Mender™ top applications:
General full depth crack repair:
Use the high-penetration abilities of Roadware 10 Minute Concrete Mender™ to make full depth crack repair.
SPALLED CONTROL JOINT
(Fully cured non-moving)
1. Clean out with diamond grinder and remove dirt and dust. Score back spall with blade for a finished look.
2. Flood with Roadware 10 Minute Concrete Mender™
3. Add a fine graded silica sand and additional liquid to grade.
4. Strike off excess material and allow to cure for 10 minutes at 70°F.
5. Open to traffic. Finish and blend with a grinding stone if desired.
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? Proprietary Polyurethane 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
|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
Start out by adding a small amount Concrete Mender to the prepared crack and noting where material in running beyond the slab. Add a light dusting of silica sand or fine quartz to the crack and some more Concrete Mender. The Concrete Mender will combined with the particles of sand to form a quick setting, “mud” at the bottom of the crack. Repeat as necessary and repair the full depth of the slab.
This will be a structural repair with no ports, no pumps, and almost no down time.
Why are my contraction joints spalling and what can I do to stop it?
joints) are joints cut into a slab shortly after pouring. The purpose of these joints is to control the cracking of the slab as it cures. Most concrete slabs shrink and sometimes curl for the first 12 months after pouring. Contraction joints allow the
slab to crack at pre-determined intervals instead of natural random cracking. Joint filler is used to protect the joints from spalling and chipping caused by traffic on the slab.
As the slab cures for the first
12 months, it shrinks in size and may even curl up at the joints. The contraction joints will expand as the slab shrinks. This causes the joint filler to split apart or dis-bond from the sides of the joint leaving them exposed to traffic.
joint. The force of the load has to transfer from the wheel, to the concrete, and to the base. If the slab is even slightly curled and the joint is expanded, the force of the load will impact on the joint causing cracking and spalling. You may even get stress cracking parallel to the joint. You can sometimes feel the uneven load transfer across the joint if you stand with one foot on either side of the joint and have someone else roll a heavy load across the joint.
the top. This will stabilize the slab, restore aggregate interlock,
and allow for complete and even load transfer from the wheels all the way down to the base. Your contraction joint problems are solved.
is recommended for interior controlled environment applications with sound concrete and base. Exterior applications may have different results. Always test a small section
of large repair for compatibility.