We're repairing a parking garage that has several isolated cracks in the traffic deck. The cracks penetrate all the way through the slabs, and water and deicing salts leak through the cracks onto the lower levels. What is the best way to repair these cracks?
We spoke to Tim Gumina at Restruction Corp. and he offered two possible solutions. The first is to inject the cracks with epoxy. He suggested injecting the cracks from the bottom up, leaving the tops of the cracks unsealed to get a good look at how well the epoxy is penetrating. Another possibility is to gravity-feed either a low-viscosity epoxy or high-molecular-weight methacrylate (HMWM) into the cracks. Some low-viscosity epoxies can penetrate cracks as narrow as 0.02 inch by gravity, but it's probably better to gravity-feed only those cracks that are at least 0.05 inch wide. HMWMs, however, have very low viscosity and can penetrate hairline cracks. To gravity-feed the materials, run a strip of caulk on each side of the crack to create a reservoir to pour the material into. When using this method, you must seal the underside of the cracks.