The bottom concrete slab of this parking garage had many cracks that were between 1/4″ to 1/2″ wide. The cracks were left alone for many years allowing water to drain into them. Overtime the concrete slab started to sink because the water started to erode the sub-base.
To help prevent further erosion, we cleaned out the cracks with a saw blade and then filled them with a flexible sealant.
Stay tuned for more pictures in a couple of weeks of other parking garage repairs. We will next be repairing spalling concrete on the slab-on-grade.
Before Repairing Crack In Parking Garage
Concrete Crack Repair in Parking Garage
Expansion joints are those big joints in concrete that typically have either a piece of wood or have an asphalt fiberboard. When pouring the concrete driveway or sidewalk they place these expansion joints to allow the concrete to expand and contract and are also places they have stopped pouring the concrete for the day. Typically there is a piece of rebar going through the expansion strip to prevent the two concrete slabs from moving away from each other.
The problem with these expansion strips is that they allow water to migrate down through the joint causing the rebar to rust. Eventually the rebar will break and allow the two concrete slabs to move independently. Another problem with these joints is that they can collect dirt and provide an area for weeds to grow.
There is a solution to these problems; you can have a joint sealant placed over the expansion joint. This will help prevent water migrating down causing the rebar to rust and will also prevent weeds from growing in the joint. The material used is a polyurethane caulk that bonds to both side of the concrete slab creating a complete water seal. Other products such as plastic or foam that are placed in-between the joint do not create that watertight seal like the polyurethane caulking.
If you have the concrete driveway acid stained you can color match the polyurethane caulk to the color of the acid stain. There is the standard grey and sand color available readily and also over 20 other colors that can be costumed made and ordered. There can also be sand sprinkled on top of the wet polyurethane to make it look more like concrete.
Take a look at these photos of an expansion joint that was sealed with sand sprinkled on top of the wet polyurethane sealant.
Expansion Joint Before
For more information visit MVL Concrete.
Expansion Joint Cleaned Out
Expansion Joint With Foam Strip
Expansion Joint Sealed With Sand Broadcasted