Method for renovation of sewer manholes involves use of lost formwork from several formwork rings and outer diameter is smaller than inner diameter of sewer manhole

摘要

The method involves use of lost formwork from several formwork rings (5). The outer diameter is smaller than the inner diameter of the sewer manhole (1). A formwork ring is inserted under formation of an annular space into the sewer manhole. The annular space is filled with a mixture to harden polyurethane hard foam (6). The next formwork ring is attached on the existing formwork ring.