[Posted on October 16th, 2013 by Ashley Aguirre]
Homeowners often need to make large investments in houses that are deteriorating under environmental stresses, age and heavy usage. What is worse is that many of these buildings are already well beyond their planned design lives. Because of this, selecting appropriate materials is important for durable and economical repairs. A home’s safety can also be considerably improved through the use of concrete overlay.
A Unique Material
A concrete overlay is an ultra-strong, easy-to-apply and durable concrete layer. For many years, it has been used widely for bridge deck and pavement restoration throughout the country. Although they are perceived as difficult and expensive to construct, they can extend the service life of an existing building when used properly.
Types of Concrete Overlays
There are two types of overlays that are being used today. The first type is the bonded overlay. A bonded concrete overlay is usually thin and often used when structural distress occurs even though the condition of the existing structure is still good. When they are bonded together, both the existing structure and the overlay work as one monolithic support.
The second type of concrete overlay is an unbounded overlay. It is usually 280 to 100 mm thick depending on the desired lifespan. These overlays act as a new structural support with an existing foundation that serves as a very stable uniform base.
When the structure is made from a composite material, there are no attempts whatsoever to spate the overlay from the existing surface. In fact, only bonding is required to add structural capacity to the current system.
When the underlying structure is made from concrete, a separation layer is often used to prevent any form of bonding between these two concrete layers. Some of the materials that are utilized include geotextile or a small portion of thin asphalt. This is because any kind of bonding between these two concrete layers can stress the overlay and may result in reflective cracking.
People should also remember that there are a number of considerations that impact a concrete overlay’s design. These include the overall thickness of the overlay and the type of overlay. If the current structure performs adequately and has minimal damage, a bonded concrete overlay is all that is required.
If the damage is more severe, an unbounded overlay can be used. Determining the thickness of the overlay is also very important to make sure that the facility has the capacity that is needed for use. The existing structure’s capacity along with the underlying sub-grade base material should be estimated or measured before determining the overlay’s thickness.
Why a Home Should Use a Concrete Overlay
Concrete overlays are perfect for any home in the U.S. They can serve as cost-effective restoration and maintenance for almost any existing structural type and condition. Well-constructed and designed overlays provide well-rounded and excellent performance. Concrete overlays are also recyclable. With the most recent construction equipment, they can be removed economically and reused as a drainable base and high-quality material for any future home improvement project.