Composition/Characteristics/Application (Summarized for brevity, as descriptions overlap or are concise):

● Pipes composed of steel cages, concrete, and steel sleeves/collars/bells, made via various processes (vibration, radial extrusion, etc.). 

● Characteristics include easy installation, low cost, low maintenance (Grooved Pipe); for steel socket pipes, the steel ring is protected within concrete, extending life; double gasket pipes allow individual joint testing, saving time/water, excellent sealing; Type G uses stainless steel bells/spigots for small-diameter jacking. 

● Applications include trench construction for gravity flow pipelines (RCP), pressure tunnels, culverts, utility tunnels (DRCP), and jacking construction.