Evaluation of Sealing Materials and Techniques for Installing Quoin and Miter Block Backing Grout

Unified Facility Guide Specifications (UFGS) 35 20 16.33 Miter Gates, specifies two types of filler materials to set miter and quoin contact blocks: epoxy and zinc. Zinc is rarely used today for safety reasons. While the epoxy filler stipulated in the guide specification is no longer available, the UFGS does permit the use of an equal product, and several are being used effectively in the field. The materials currently in use have low viscosities and are typically poured behind the quoin and miter blocks in sections. Gaps are typically sealed with commercial fillers. Often, the surface preparation on the quoin block and channel is not ideal for proper adhesion. This is not a problem for the epoxy filler materials since they are applied in a confined space and are loaded in compression. However, the sealing materials can fail as the pressure head of the epoxy material increases while it is being poured. This pressure can cause the epoxy material to leak out. When this happens, the gap must be cleaned and resealed. This work was undertaken to resolve the problems associated with pouring epoxy fillers, and to recommend improvements to the process.