GU-International - GU Baseliner

(E) INSTALLATION IN CONCRETE (PRECAST):
1.0 The PE and/or FRP cone and flat slab top liner shall be cast integrally within monolithic precast concrete manhole riser section(s) or lift station/wet well section(s) in accordance with the liner manufacturer’s recommendations and specifications.
1.1 The “Wet Cast” method is the recommended precasting process for lift station/wet well liners.
1.2 Inside surfaces of PE and/or FRP liners shall be free of bulges, dents and other defects that could interfere with the fit and seal to the section joint. No liner shall have holes or openings which will permit the intrusion of liquids or gasses through the liner wall and into the concrete matrix. Manhole lifting devices shall not penetrate any surface of the liner.
1.3 The access opening of the liner must be fully supported during the casting process.
1.4 The precast concrete joint surface shall be of one plane and free of excess concrete to assist in creating a proper seal with the section joint.
1.5 The finished cone or flat slab to shall not be moved until adequate hydration has occurred so as to not damage a semi-rigid casting.

(F) FIELD ASSEMBLY AND INSPECTION OF PRECAST CONCRETE CONES AND FLAT SLAB TOPS WITH PP AND FRP LINERS:
1.0 Outer joints of precast concrete sections shall be gasketed or sealed as directed by the utility and/or precast manufacturer.
1.1 All internal PE and/or FRP seams at the section joints shall be sealed.
1.2 Recommended method of sealing internal PE and/or FRP joint seams is with preformed butyl strips (ASTM C-990 section 6.2) applied to the top face of the outward facing horizontal return of the liner at the same time as gaskets or other sealing materials are attached to the outer joint (see supply sources for preformed buytl strips).
1.3 Mechanical anchoring attachments through liner surfaces must be sealed with an approved elastomeric sealant. (See approved source recommendations).
1.4 After assembly is complete, the interior surface of the liner shall be free of pinholes, cracks, pits or defect which are detrimental to the intended use of the liner. No liner shall have holes or openings with will permit the intrusion of liquids or gasses through the liner wall and into the concrete matrix. There shall be no exposed concrete/mortar on any liner surface to include (but not limited to) section joints, hatch frame/cast iron frame and cover mating/sealing surface.
1.5 Testing of the lined lift station/wet well structure to meet pressure test of 1 bar (14.7 PSI) or the prescribed ASTM criteria for vacuum testing.
PLEASE NOTE: There is no correlation between vacuum (air) and hydrostatic tests (see ASTM C1244-93). Vacuum testing with the presence of hydrostatic pressure (high ground water conditions) provides unreliable test results.

SUPPLY SOURCES OF RECOMMENDED ELASTOMERIC BUTYL SEALANTS AND ADHESIVES FOR INSTALLATION OF THE PP AND/OR FRP MANHOLE BASE LINER

BUTYL RUBBER PREFORMED FLEXIBLE JOINT SEALANT

(MECHANICAL ANCHOR PENETRATIONS AND REMEDIAL “CAULK” SEAL OF MISCELLANEOUS JOINTS OR SEAMS - 1” WIDTH OR LESS)
NOTE: The sealant manufacturer’s application and surface preparation procedures (including primer) must be followed. This includes recommended maximum joint depth of 1/2” (1/4” minimum thickness) and the use of bond-breaker polyethylene closed cell foam backer rod or polyethylene bond breaker tape.

BONDING AGENT FOR DISSIMILAR MATERIALS I.E. POLYPROPYLENE,
POLYETHYLENE, FIBERGLASS, URETHANE & VARIOUS METALS ETC.