Concrete Repair & Demolition
Cementwright offers both concrete demolition and repair. Typically a demo job will precede a repair job, and as with our other concrete services, we’ve found that we are able to streamline projects and offer better value by providing both. We have the usual saws, demo hammers, and specialty skidsteer attachments, as well as more obscure tools like hand-held hydraulic shears for tight areas. These combined with our knowledge of concrete lets us do specialty jobs others avoid. We can do technical work such as infrastructure & industrial localized demolition and repair as well as the more common slab demolition and repair/replacement. We work with our own and outside experts to analyze the concrete failure so we can prevent reoccurence.
Consider the repair when demolishing concrete
Preparation is key for a successful repair. This happens in conjunction with demolition; removing the deteriorated material correctly will also prepare the parent material to accept the repair. In some cases it is necessary to remove the concrete without damaging the reinforcing structure in order to retain structural integrity. Controlling and streamlining the demolition to manage quality and prevent duplicate efforts is a big reason why we perform our own cutting and demolition.
Prepare for your concrete repair
Different repair processes have different prep requirements, so be certain to find and follow those for your selected system. Longevity of the repair is limited by the quality of the prep. All deteriorated material will need to be removed. The patch is only as good as its bond to the substrate, so leaving weak material severely limits the patch. Mechanically bonded systems will require a certain surface profile, usually specified as an ICRI number. This gives the patch a surface area to physically grab onto. Chemically bonded systems can usually be applied to smoother surfaces, but check your instructions. In all cases materials like dust or grease will interfere with the bond. Be cautious of acid etching to roughen the surface. This can weaken the concrete and therefore the subsequent repair or coating.
Design the concrete patch system
Pay attention to the minimum thickness of the patch material- some patches can go to feather edge with correct prep, and others cannot. Many concrete repair systems will require a key, or a cut to a specified depth perpendicular to the surface in order to maintain a specified concrete depth or aspect ratio for the cut. Be careful in doing this to retain sufficient structural integrity of the assembly- it might be better to replace down to the subgrade rather than to install a topical patch. If necessary we can refer structural engineers to help with patch design.
Material selection is also salient. It’s usually ok to replace a big area of a floor slab with regular concrete, but better to use a non-shrink technical system for a pocket patch on a structural slab. We are familiar with multiple ways of repairing concrete and will work with you to create a good result.
Repair vs concrete replacement
Ensure that the concrete is worth repairing in the first place. Failures from ASR (Alkali-Silica Reactivity), which might be considered analogous to concrete corrosion, subgrade movement, frost damage, and several other modes, can be expensive or impossible to reliably remedy. We get a lot of requests to apply a topping on cracked, chipped, or otherwise deteriorated concrete. In almost all cases, this is a waste of money because it does not address the reason why the concrete originally failed. Cracks resulting from subgrade movement ( any of frost, moisture, dynamic load) will telegraph through any repair. Deteriorated concrete will continue to deteriorate and the concrete overlay will delaminate and fail. Cases like this will require full removal and replacement, which often includes a structural rebuild of the gravel base. With that said, we have other options for refreshing old concrete, such as exposing aggregate or disguising blemishes. If you’re unsure what suits your project, give us a call and we’ll help with options.
CementWright believes in doing our projects efficiently. To us, this means doing them as well as we can so they do not have to be done again. We are happy to provide input on your demolition and repair project, and will work to provide solutions that will last. Contact us to get started.