A pre-stressed concrete pipe is made by casting a concrete pipe inside a metal cylinder and then being pre-stressed by injecting solidifying compound under pressure into the boundary between the metal cylinder and concrete pipe, and includes a pair of end rings within the metal cylinder, each having a metal ring with an annular groove and an elastic band having a curved end to provide a rounded corner on the concrete pipe. After the solidifying compound is solidified, the concrete pipe retains the compression increasing its strength to withstand pressure, and moments caused by external loads. The pre-stressed concrete pipe further includes a bell ring mounted at one end and a spigot ring having a gasket ring at the other end. A bell clamp is mounted on the bell ring.

A donut-shaped component is set around an end of a pipe and both are cast into a concrete slab. Removal of the donut after the concrete has cured leaves an annular recess in the concrete slab around the pipe, which remains in the concrete. Donuts used at both ends of the pipe result in two annular recesses in the concrete, one at each end of the pipe. A cover can be used on the top donut. Further piping connections are made in the annular recesses. The use of firestopping may be avoided, and water leakage through the slab may be eliminated.

Precast collars for screw type anchors that have a body made of a high strength composite or concrete material. The body having an opening to receive an anchor base head portion of an anchor so that a structure to be supported by the anchor is in direct contact with the anchor.

Precast collars for screw type anchors that have a body made of a high strength composite or concrete material. The body having an opening to receive an anchor base head portion of an anchor so that a structure to be supported by the anchor is in direct contact with the anchor.

Precast collars for screw type anchors that have a body made of a high strength composite or concrete material. The body having an opening to receive an anchor base head portion of an anchor so that a structure to be supported by the anchor is in direct contact with the anchor.

Precast collars for screw type anchors that have a body made of a high strength composite or concrete material. The body having an opening to receive an anchor base head portion of an anchor so that a structure to be supported by the anchor is in direct contact with the anchor.

Precast collars for screw type anchors that have a body made of a high strength composite or concrete material. The body having an opening to receive an anchor base head portion of an anchor so that a structure to be supported by the anchor is in direct contact with the anchor.

Precast collars for screw type anchors that have a body made of a high strength composite or concrete material. The body having an opening to receive an anchor base head portion of an anchor so that a structure to be supported by the anchor is in direct contact with the anchor.

Precast collars for screw type anchors that have a body made of a high strength composite or concrete material. The body having an opening to receive an anchor base head portion of an anchor so that a structure to be supported by the anchor is in direct contact with the anchor.

Precast collars for screw type anchors that have a body made of a high strength composite or concrete material. The body having an opening to receive an anchor base head portion of an anchor so that a structure to be supported by the anchor is in direct contact with the anchor.