A method for renovating the interior of a hollow structure such as a sewerage pit (1) is described. The method provides an access opening (16) to the hollow structure (1); provides a plurality of material sheets (3) comprising reinforcing fibers and a curable resin composition through the access opening (16) and against a wall (11a, 11b) of the hollow structure (1); and provides an inflatable pressure means (4a, 4b) within the hollow structure (1). The pressure means (4a, 4b) are inflated against the wall (11a, 11b). A curing means (6) is then provided within the hollow structure (1) for curing the resin composition; and the resin composition is cured to harden the material sheets and provide a renovated interior of the hollow structure (1).

A prefabricated composite concrete element for use in a corrosive sewer environment. The concrete element has a hollow reinforced cast concrete portion with at least one end having connection details, a premolded corrosion resistant inner plastic liner. The plastic liner lines an interior of the hollow concrete element and the connection details to provide abutting liner faces in an assembled joint to limit exposure through said joint of said concrete portion to corrosive materials arising in said sewer environment. At least two prefabricated composite concrete elements may be assembled end to end at a joint to form a concrete sewer system. Also disclosed are a method of prefabricating such a composite concrete element.

A manhole base assembly and a method for making the same employ a non-cylindrical, low-volume concrete base that is fully lined to protect the concrete against chemical and physical attack while in service. This lined concrete manhole base assembly may be readily produced using a modular manhole form assembly which can be configured for a wide variety of geometrical configurations compatible with, e.g., varying pipe angles, elevations and sizes. The form assembly is configurable to provide any desired angle and elevation for the pipe apertures to interface with various underground systems, and can be formed on-site to facilitate compatibility with existing structures. The assembly provides for flexible, modular construction of a wide variety of lined manhole base assemblies at minimal cost, reduced concrete consumption and reduced operational complexity. The modular nature of the production form assembly also facilitates reduced inventory requirements when various manhole base assembly geometries are needed.

Disclosed herein is a free-standing cesspool and a cesspool liner that may be used to retrofit existing cesspools in order to provide additional storage and/or processing for raw sewage before the sewage leaches out of the cesspool.

A prefabricated composite concrete element for use in a corrosive sewer environment. The concrete element has a hollow reinforced cast concrete portion with at least one end having connection details, a premolded corrosion resistant inner plastic liner. The plastic liner lines an interior of the hollow concrete element and the connection details to provide abutting liner faces in an assembled joint to limit exposure through said joint of said concrete portion to corrosive materials arising in said sewer environment. At least two prefabricated composite concrete elements may be assembled end to end at a joint to form a concrete sewer system. Also disclosed are a method of prefabricating such a composite concrete element.

The present invention is a method for rehabilitating, repairing, and replacing manholes and connected sewer lines. In some embodiments, a compressed liner is inserted through the manhole access hole or the connected sewer lines. Prior to insertion, the liner may be cut and/or folded to be compressed to a size that can fit through the manhole opening or the sewer lines. Once inserted in the manhole or sewer lines, the liner should be expanded, and if necessary, bonded together with a resin along the separation line. Next, a bonding material may be injected between the liner and a surface of the manhole or sewer line to seal any cracks or fissures in the brick or concrete wall and to seal the liner against the existing manhole or sewer line to improve structural integrity and longevity. A new corbel may then be installed and bonded to the liner.

A prefabricated part comprises a concrete body that has the form of a pipe section with two pipe ends and a pipe inner side. The pipe inner side is lined at least in some areas by a lining made of plastic material connected to the concrete body, and at least one of the pipe ends is covered at least in some areas by a molded part made of plastic material connected to the concrete body. At least the pipe end, which is covered at least in some areas, has a connecting joint in order to connect the pipe end to a pipe end of a further prefabricated part. The lining consists of a thermoplastic material and the molded part consists of a thermosetting plastic. The lining and the molded part are connected to each other in a sealed manner.

A prefabricated part comprises a concrete body that has the form of a pipe section with two pipe ends and a pipe inner side. The pipe inner side is lined at least in some areas by a lining made of plastic material connected to the concrete body, and at least one of the pipe ends is covered at least in some areas by a molded part made of plastic material connected to the concrete body. At least the pipe end, which is covered at least in some areas, has a connecting joint in order to connect the pipe end to a pipe end of a further prefabricated part. The lining consists of a thermoplastic material and the molded part consists of a thermosetting plastic. The lining and the molded part are connected to each other in a sealed manner.

A form for a plastic lined septic system distribution box is configured to receive a fill material. The form includes a jacket, a plastic core, a plastic inlet ring, and a plastic outlet ring. The jacket defines an exterior wall and exterior floor of the distribution box. The core defines an interior wall interior floor of the distribution box. The inlet portal ring and outlet portal ring extend between the core interior wall and the jacket exterior wall. The core and jacket are arranged to leave a space therebetween to receive the fill material, and the core is configured to serve as the interior wall and interior floor of the distribution box and to line the fill material for the distribution box during use.

The present invention is a method for rehabilitating, repairing, and replacing manholes and connected sewer lines. In some embodiments, a compressed liner is inserted through the manhole access hole or the connected sewer lines. Prior to insertion, the liner may be cut and/or folded to be compressed to a size that can fit through the manhole opening or the sewer lines. Once inserted in the manhole or sewer lines, the liner should be expanded, and if necessary, bonded together with a resin along the separation line. Next, a bonding material may be injected between the liner and a surface of the manhole or sewer line to seal any cracks or fissures in the brick or concrete wall and to seal the liner against the existing manhole or sewer line to improve structural integrity and longevity. A new corbel may then be installed and bonded to the liner.