Chapter 15 – Specialized Repairs

Publisher Summary This chapter focuses on various specialized repairs with lock walls for rehabilitation of existing concrete. The rehabbing of lock walls can involve basic scaling to deeper damage. It is common to remove anywhere from 1–3 ft of concrete from the face of a lock wall. New Portland cement concrete is then used as a conventional concrete to resurface the wall. Cast-in-place concrete can be economically feasible. Much of the cost factor is related to the depth of a repair. Blasting of lock walls is a common method of surface preparation before a repair is made. Workers often drill small-diameter holes along the top of a lock wall in a direction parallel to the removal face. Concrete placement for the repair of lock walls is pumped or poured into forms. This may be done with flexible piping. The heights of walls vary. Some full-face pours may be as tall as 50 ft. Preplaced-aggregate concrete is more resistive to shrinkage and creep than conventional concrete because of the aggregate.