Anchor Bolt grouting procedures

This guide addresses proper procedures for the anchoring of embedments (bolts,threaded rod, rebar) into concrete.

Typically, a structural engineer evaluates several factors before proceeding with an anchor bolt grout project. Anchor strength and long term performance are dependent on a variety of factors. Some factors to be considered include material strength, hole diameter and drilling system used, embedment length, annular gap between the anchor and edges, temperature, hole cleaning, mode of failure of the anchor system, environmental conditions such as moisture and subsequent chemical attack. In critical applications it is often recommended that a site test take place to verify performance.

STEPS to properly install anchors:

Step 1

Drill a hole the diameter size and depth of embedment required. Typically the diameter of the hole should be no larger than 1/4 inch (6mm) wider than the diameter of the anchor. For good quality concrete the hole depth is generally 10-15 times the diameter of the embedded anchor.

Step 2

Scrub the hole with a stiff bristle brush to remove all dust, dirt, debris or any other bond-inhibiting material from the drilling procedure.

Step 3

Blow the hole clean with oil-free compressed air, brush, and blow it clean again. Holes should be clean and sound.

Step 4 

Mix the epoxy in accordance with the technical data sheet of the product being used. If setting anchors in horizontal slabs you may use a LV, MV, or GEL expoxy formulation. If setting anchors into a wall you must use a GEL expoxy. Also, select your epoxy formulation based upon ambient and surface temperatures, setting times, etc. Condition epoxies prior to use when working in cold or hot environments.

Step 5 

Place the mixed resin adhesive in the rear of the prepared drilled anchor bolt hole. Avoid creating air pockets within the hole. If using a static mixer put the nozzle of the mixer to the back of the hole and slowly withdraw the nozzle as the material is dispensed. Fill to approximately 1/2 the hole depth.

Step 6 

Inset the anchor slowly with a twisting motion into the hole forcing it to the bottom until the resin adhesive flows to the top. Twist the anchor to ensure intimate contact and establish bond.

Step 7

Allow the epoxy adhesive to cure undisturbed for the specified time prior to applying any load.

(This document is not our original, just for reference and study.)