SEWER MANHOLE REHABILITATION
PERMACASTâ BY AP/M PERMAFORMâ
1 Intent: It is the intent of this specification to provide for the waterproofing, sealing, structural enhancement and corrosion protection of existing manholes, wet wells and similar underground structures from the cover to the channel. This specification offers flexibility in design by offering current technologies available for repairing the various defects found in sanitary sewer structures from minor leaks to complete structural failure.
2 General: This specification establishes the minimum standard for materials and method of application for the waterproofing, sealing, structural enhancement and corrosion protection of existing manholes, wet wells and similar underground structures from the cover to the channel. The repair methods may be engineered for the groundwater pressures, dimensions and condition of each manhole.
3 Referenced Standards
3.1 ASTM C-39 Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
3.2 ASTM C-94 Standard Test Method for Ready-Mix Concrete
3.3 ASTM C-109 Standard Test Method for Compressive Strength of Hydraulic Cement Mortars
3.4 ASTM C-143 Standard Test Method for Slump of Hydraulic Cement Concrete
3.5 ASTM D-149 Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies
3.6 ASTM C-157 Modified Standard Test Method for Length Change of Hardened Hydraulic Cement Mortar and Concrete
3.7 ASTM C-293 Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with Center-Point Loading)
3.8 ASTM C-309 Standard Specification for Liquid Membrane-Forming Compounds for Curing Concrete
3.9 ASTM C-403 Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance
3.10 ASTM C-469 Standard Test Method for Static Modulus of Elasticity and Poisson's Ratio of Concrete in Compression
3.11 ASTM C-496 Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens
3.12 ASTM D-570 Standard Test Method for Water Absorption of Plastics
3.13 ASTM C-882 Standard Test Method for Bond Strength of Epoxy Systems Used with Concrete by Slant Shear
3.14 ASTM C-1090 Standard Test Method for Measuring Changes in Height of Cylindrical Specimens from Hydraulic-Cement Grout
3.15 ASTM C-1202 (AASHTO T 277 Equivalent) Electrical Indication of Concrete’s Ability to Resist Chloride Ion Penetration
3.16 ASTM D-1653 Standard Test Methods for Water Vapor Transmission of Organic Coating Films (Method B)
3.17 ASTM D-4541 Pull-off Strength of Coatings Using a Portable Adhesion Tester
3.18 ASTM D-4414 Standard Practice for Measurement of Wet Film Thickness of Organic
Coatings by Notched Gages
3.19 NACE RP0274 High Voltage Electrical Inspection of Pipeline Coating Prior to Installation
3.20 NACE 6/ Surface Preparation of Concrete
SSPC-SP 13
4 Inspection and Evaluation
5 Leak Plugging and Offset Patching
Plugging and Patching and Material
5.1.1 Permacast-Plugä
5.1.1A A quick setting hydraulic cement compound used to quickly stop running water or seepage leaks in masonry and concrete. The Permacast-Plugä formulation is nonshrinking, nonmetalic, and noncorrosive. Permacast-Plugä requires only potable water for mixing and achieves initial set in 1 to 3 minutes, even when applied under water.
5.1.1B Permacast-Plugä is used above or below grade, interior or exterior, to stop seepage and flowing water leaks in most concrete and masonry walls and floors. The fast initial set, high strength, and controlled expansion, make Permacast-Plugä the ideal patching material for use in manholes, wet wells, lift stations, and other structures subject to leakage. Permacast-Plugä will not permanently seal running water leaks that are caused by thermal or structural movement.
5.1.2 Permacast-Patchä
5.1.2A A fast setting, ready-to-use, cement based concrete and masonry patching compound formulated specifically for underwater use. It requires only potable water for mixing. Permacast-Patchä achieves initial set in 3 to 5 minutes and final set within 20 minutes even under water. After initial set, Permacast-Patchä may be shaved to conform to the contours of the surrounding surface. Properly mixed and applied, Permacast-Patchä quickly develops a very high strength and a tenacious bond.
5.1.2.B Permacast-Patchä is used underwater or below grade on vertical, overhead, and horizontal surfaces. It is used for the patching of manholes in preparation for the PERMACASTâ liner application and is particularly well suited to fill offset bricks in the corbel area.
5.1.3 MS-10,000 ULä
5.1.3.A PERMACASTâ MS-10,000 UL is designed to provide a thick underlayment that fills mortar joints, cracks and voids in brick and masonry manholes. The underlayment provides a sound substrate onto which the structural liner is spun cast at the specified thickness of ½”-2” to reinforce and seal the existing structure.
6 I & I Prevention at the Frame Chimney Joint
6.1 Manufactured Seal at Frame and Grade Rings
6.1.1 I & I Barrier Description
6.1.1.A The I & I is a molded polymer shield that is incorporated into the chimney section of a manhole assembly including grade adjustment rings. Properly installed, the I & I Barrier provides an impermeable shield against the infiltration of ground water and eroded soil. It is an established fact that grade rings alone, whether they are concrete, plastic or rubber will not provide a leak proof system. Ground movement from freeze/thaw cycling and traffic flow will loosen joints and allow the system to leak. When the I & I Barrier is installed, it provides an inner wall that diverts the inflow back out instead of into the collection system. The I & I Barrier is cut to height and installed on top of the cone. The cut height is determined by adding the adjustment ring stack up dimension to the inside height of the cover frame. Caution should be used to not interfere with the complete seating of the cover into the frame. The joints between the cone and the I & I Barrier are sealed using butyl mastic caulk as described in the general installation instructions. The adjustment rings, cover frame and cover are then installed as usual.
6.1.2 I/I Barrier Installation
6.1.2.A The bottom surface of the I & I BARRIER flange shall be sealed to the manhole cone top surface using Cor+Gard Flex-Joint as specified in section 6.1.3.
6.1.2.B The sealant shall be applied to the top surface of the manhole cone section only. Sufficient sealant must be used to accommodate flaws in the cone surface and “out-of-flat” conditions. The amount of sealant and its placement will be determined by the condition of the cone. This determination will be the responsibility of the contractor installing the I & I BARRIER. The I & I BARRIER is then centrally seated on the cone against the sealant. The bottom adjustment ring is then centrally placed on the top surface of the I & I BARRIER flange using no sealant.
6.1.2.C If plastic adjustment rings with a vertical tongue are being used, the tongue must be cut off to allow the bottom ring to set flush on the I & I BARRIER flange. This removal should be done per instructions from the adjustment ring manufacturer. Concrete grade rings may be stacked and shimmed dry or with mortar. Additional sealant is not required between the grade rings. The chimney section is then completed based on the type of adjustment rings being utilized.
6.1.2.D The I & I Barrier is manufactured from medium density polyethylene as defined by ASTM designation D 1248 and having the following properties:
|
Melt Index, ASTM D-1238 |
4.5 |
|
Density, ASTM D-792 |
.938 |
|
Tensile strength at yield, psi, ASTM D-638 |
2800 |
|
Elongation at break, %, ASTM D-638 |
400 |
|
Flexural Modulus, tangent, psi, ASTM D-790 |
115,000 |
|
ESCR, ASTM D-1693 |
1000 |
|
UL-94 @ .060 & @ .120 thickness, UL-94 |
HB |
|
Deflection Temp, 88 psi, °C, D-648 |
83 |
|
Deflection Temp, 264 psi, °C, D-648 |
42 |
|
Low Temp Impact, -40°C, ft-lb, ARM |
68 |
6.1.2.E This plastic resin produces a product that has excellent low temperature impact resistance, excellent environmental stress crack resistance and it is highly resistant to degradation from sunlight. UV resistance was tested in accordance with SAE Test Procedure J-1960. The material shows an increase in elongation at break values and 87% retention of tensile strength after 10,000 hours exposure.
6.1.2.F A 25,000 pound load distributed over the 533 square inch area of the I & I Barrier flange represents a 47 pounds per square inch load. Passing the proof-load testing of AASHTO Designation M-306 represents a load bearing capacity in excess of 494 pounds per square inch. When multiplied by the 494 pounds per square inch value over the 533 square inches of bearing surface, a product load capacity of over 250,000 pounds or 125 tons is achieved.
6.1.3 Cor+Gard Flex-Joint
6.1.3.A Cor+GardÒ Flex-Joint is a fast cure, high strength adhesive/sealant. Flex-Joint exhibits excellent adhesive properties to many substrates including aluminum, brass, steel, glass, mortar, concrete, wood and many plastics. Flex-Joint is highly weather and corrosion resistant. Contains no solvents or isocyanates and is non-yellowing.
6.1.3.B
|
Specific Gravity |
1.4 – 1.5 |
|
Tack Free Time |
Less than an hour @ 77°F/50% RH |
|
Skin Time |
Less than 30 minutes @77°F/50% RH |
|
Sag |
Non-sagging |
|
Tensile Strength |
475 psi |
|
Lap Shear |
550 psi |
|
Elongation |
Approx. 500% |
|
|
Up to 400°F for short periods |
|
|
Properties retained to -75°F |
|
Shore A |
45-50 |
|
Corrosive Properties |
Non-corrosive |
|
Staining |
Non-staining |
6.1.4 Field Testing for Leaks
6.1.4.A A simple field test can be utilized to assure the integrity of the seal between the I & I BARRIER and the manhole cone prior to back-filling the installation. Fill the excavated area around the chimney section with water to a level above the joint between the I & I BARRIER and the manhole cone top. NOTE: Sufficient weight must be applied to the I & I BARRIER flange to affect a seal. Inspect the area inside the manhole below the cone upper edge for any signs of leakage. If moisture is present, sufficient sealant has not been applied to affect a seal. Reseal as necessary and retest.
6.2 Interior Flexible Chimney Seal
6.2.1 Cor+Seal Frame Chimney Sealant
6.2.1.A COR+SEALä is a two component, aliphatic, chemically curing, urethane sealant formulated as a high build coating to seal the adjustment ring to the casting of manholes and catch basins. Provides corrosion protection and abrasion resistance. Designed to provide super flexibility to absorb ground movement and extended water immersion when applied to the inside wall of the adjustment ring. May be used internally or externally.
6.2.1.B Cor+Seal Physical Properties
|
Tensile Strength |
ASTM D 412 |
1100 psi |
|
Elongation |
ASTM D 412 |
750% |
|
Adhesive Strength |
ASTM D 903 |
175 l/in. |
|
Tear Resistance |
ASTM D 1004 |
165 l/in. |
|
Hardness |
ASTM D 2240 |
72 |
|
Movement Capability |
ASTM C719 |
50% |
|
Hardness (Shore A) |
ASTM C661 |
50 |
|
Low Temperature (Flexibility @ -4°F) |
ASTM D1790 |
Pass |
|
Heat Aging |
ASTM C920 |
2% |
|
Recovery |
ASTM C920 |
98% |
|
Shelf Life @ 70°F in sealed containers |
|
9 months |
|
Bond Durability |
Test Blocked at 25% for 48 hours |
|
Water Immersion |
Samples on masonry block will withstand water immersion while elongated 50%
|
6.2.2 Cor+Seal Installation
6.2.2.A After preparing the surface by sand blasting to remove loose material and rust, brush on primer coat. When primer coat becomes tacky, thoroughly mix parts A & B separately. Combine A & B and mix thoroughly and trowel or brush this mixture onto the prepared surfaces at a thickness of 80 to 100 mils (about the thickness of two US Quarters. Overlap the bottom portion of the casting and the top of the lowest adjustment ring by 3 inches. The flexible sealant will become tack free within 60 minutes and fully cured within 24 hours.
6.2.3 Cor+Flex Chimney Sealant Description
6.2.3.A COR+FLEX is a two-component, high performance urethane elastomeric coating specifically designed for high build applications. When fully cured, COR+FLEX forms an extremely tough, abrasive resistant rubber like coating, especially suited for applications requiring protection from impact, abrasion or corrosion on metal or concrete surfaces. The system has added UV stabilizers and provides corrosion, weather, and abrasion resistance to various surfaces.
6.2.3.B Cor+Flex Physical Properties
|
Property |
B Component |
A Component |
|
|
|
|
|
Appearance at 25°C |
Blue Liquid |
White Liquid |
|
Specific Gravity at 25°C |
1.09 |
1.04 |
|
Viscosity at 25°C, mPas |
2,500 |
1,500 |
|
Flash Point, PMCC, °c |
216 |
179 |
|
VOC,% |
0 |
0 |
|
|
|
Unit |
Value |
|
Specific Gravity |
D792 |
|
1.083 |
|
Density |
D792 |
lb/ft3 |
67 |
|
Hardness |
D2240 |
Shore A |
85 |
|
Taber Abrasion |
D4060 |
|
|
|
H-18 Wheel, 1000-g Load, 1,000 Cycles |
|
mg/loss |
190 |
|
Tensile Strength: |
D412 |
lb/in2 |
1,330 |
|
Ultimate Elongation |
D412 |
% |
580 |
|
Tear Strength |
|
|
|
|
· Die C |
D624 |
lbf/in |
330 |
|
· Split |
D1938 |
lbf/in |
140 |
|
Water Absorption: 30 Days |
D570 |
% |
1.0 |
|
Crack Bridging 1000 Cycles |
C 957 |
- |
passes |
6.2.4 Cor+Flex Installation
6.2.4.A Surfaces to be coated must be clean and dry. Sandblast the casting to remove any loose debris and rust. Powerwash to remove any debris left from sandblasting and ensure the masonry interface is free of debris, release oil, or other contaminants. Apply primer to areas to receive Cor+Flex. Once the primer becomes tacky begin applying Cor+Flex. Applying COR+FLEX is very much like spraying paint. You must keep the spray pattern perpendicular to the surface being sprayed. Maintain a nice straight smooth motion. To achieve the best coverage, each pass of the spray pattern should overlap the preceding pass by approximately 1/3. COR+FLEX can be applied in thicknesses from about 30 mils to 1/2 inch or more. On horizontal surfaces, thicknesses of about 1/8 inch can be achieved in a single pass. On vertical surfaces be careful not to apply to quickly or thickly in one spot. If running occurs, control by: 1)Traversing across the surface faster, 2) Moving the spray gun back from the surface, or Reducing the output of the spray gun. Multiple layers to achieve desired film thickness is possible with multiple coats, however the time between layers should not exceed 40 minutes.
