Patent ID: 9631339
Date: 2017-04-25
CPC Classifications: E02D,E03F,E21D

Claim:
1. A method for rehabilitating a pre-cast concrete structure, the pre-cast concrete structure having an inner wall defining an annular passageway through said pre-cast concrete structure, the method comprising: providing a plurality of pre-cast, one piece annular inserts, each of the plurality of annular inserts comprising an inner wall and an outer wall, said inner wall defining a passageway through said annular insert, wherein each of the annular inserts comprises a gravel aggregate; stacking the plurality of annular inserts in the annular passageway such that the outer wall of each of the plurality of annular inserts and the inner wall of the pre-cast concrete structure define a void; inserting grout into the void between the outer wall of each of the plurality of annular inserts and the inner wall of the pre-cast concrete structure; and further comprising forming a seal between adjacent ones of the stacked plurality of annular inserts; wherein the seal between adjacent ones of the stacked plurality of annular inserts comprises an H-shaped annular seal.