Epoxy Grout In Oversized Holes

Regular epoxies are not designed to have more than 1/8" coverage in an anchoring environment. Why? Because it is too brittle when there is that much coverage and becomes weaker. More is not necessarily better. I have seen engineers ask for or specify an epoxy in a 2" pile hole with 3/4" rebar. I am unsure why they do it, but it really needs to be an epoxy grout when they ask for it that way. When they specify actual non shrink grout the issues I am about to address do not apply. You can buy epoxy grout or you can make your epoxy grout with an LV (Low Viscosity), MV (Medium Viscosity) or a Gel (Gels are not rated with viscosity, they are gels). To make an epoxy grout you need about 3 parts of 20/40 graded sand. You need to use kiln dried sand. It can not be regular masonry sand just sitting in a big pile on the job site. It is wet or has moisture in it that cannot be used with the epoxy. The sand helps extend the epoxy and acts as a heat sink as the epoxy is curing. Epoxies get very hot when in too thick an environment which affects their curing and ultimately their strength. When you make the epoxy grout as opposed to straight epoxy in the anchored situation you end up spending less and getting a better performing product.