Rehabilitation Alternatives MWEA Collection System Seminar October 1, 2009
Overview Types of Rehabilitation Trenchless Categories On-Line Replacement In-Situ Options Selecting the Best Solution
Types of Rehabilitation Excavation and Replacement Trenchless Technologies Reference: New Pipes for Old: A Study of Recent Advances in Sewer Pipe Materials and Technology, Project 97-CTS-3, Water Environment Research Foundation, 2000
Trenchless Categories On-line Replacement In-Situ Renovation
Options for On-Line Replacement Method Pipe Bursting- Pneumatic Diameter Range, inches Installation Length, feet Old Pipe Material 2-24 475 Ductile Iron, VCP, Concrete Hydraulic 2-24 475 Ductile Iron, VCP, Concrete Application Gravity and Pressure lines Gravity and Pressure lines Static Pull 4-24 650 Concrete, VCP Gravity sewers Extraction 4-14 250 Ductile Iron, Steel Cutters & Expanders Pressure lines 1-6 300 Steel, PE, PVC Pressure lines
Pipe Bursting / In-Line Expansion Description: outwardly displacing the existing pipe to make room for a slip lined pipe. Normally used with short sections. Allows for larger diameter pipes than existing pipes Options: static (no moving internal parts) or dynamic (provide pneumatic or hydraulic forces at point of impact) expansion heads Static Dynamic
In-Situ Options Slip-Lining Close-Fit Lining (CIPP) Coatings - Structural Point Repairs
Slip Lining Description: Slide a flexible pipe of a slightly smaller diameter into the existing pipe the space between new and old pipe is grouted (foam, pea gravel, etc.) continuously prevent leaks and improve structural integrity Restrictions/ requirements: Can use with pipes that have structural problems. Requires ground surface access to lower the discrete pipe sections large access pit. Doesn t require elimination of normal flows Options: continuous segmental and spiral wound: HDPE (high density polyethylene), PP (polypropylene), PET-R (fiberglass reinforced polyesters), TR-R (reinforced thermosetting resins), and PVC (polyvinyl chloride). Some use small sections of stainless steel sleeves Continuous Spiral Wound Segmental
Advantages of Sliplining It can be applied to most types of sewer pipe It is rapid and causes little disturbance to other buried utilities Depending on flows, installations can be done in live lines without bypass pumping It is most successful when there are long runs with few connections An improved interior surface with a reduced friction coefficient helps to improve flow
Considerations of Sliplining The reduced pipe diameter will cause loss of cross-sectional capacity When short pipe sections are used, the benefits of sliplining have to be offset against the increased cost of the jointing techniques Where connections are being made, the relative movements of the original pipe and the sliplined pipe need to be considered Poorly controlled grouting to the annular space can lead to buckling of the liner pipe
Types of Close-Fit Lining Systems Method Diameter Range, inches Max Installation Length, feet Liner Material Application Spirally Wound 4-100 300 PVC Gravity pipelines Diameter Reduction Fold and Form Liners 4-24 300 PE, PP Gravity and Pressure pipelines 4-64 300 PE, PVC Gravity (PVC) and Pressure (PE) pipelines CIPP (inverted) 4-100 3,000 Resin-saturated fabric tube CIPP (winched) 4-54 500 Resin-saturated fabric tube Gravity and Pressure pipelines Gravity and Pressure pipelines
Fold and Formed / Rolldown Description: fold and formed is when flexible pipe in a U shape is inserted into host pipe. Rounding mandrels round out the pipe. Then liner is heated and pressurized to conform to original pipe shape. Swagelined and rolldown use chemical and mechanical forms respectively to temporarily compressed the lining before being drawn into the pipe. Restrictions and requirements: heat and pressure are used to create a snug fit between lining and pipe. Requires carful cleaning of the pipe. Also should give time for stabilizing because of high coefficient of expansion of material Options: PVC, PE, HDPE, high tensile polyester reinforced polyethylene
Advantages of Fold and Form Liners Disruption and risk of damage to other buried utilities is minimized Severely corroded pipelines can be lined The liners are resistant to attack from most acids Despite a slight loss of cross-sectional area, the smooth interior surface of the liner may improve flow capacity Dimples in the lining indicate connections, which can be opened by robotic cutters No grouting is required
Considerations for Fold and Form Liners Reversion may sometimes not be completed fully Stresses may be locked into the liner, which over time can cause the liner to move in relation to the pipe The long-term performance of these liners is not fully researched
Cured In Place Pipe - CIPP Description: a flexible liner such as felt that is impregnated with thermosetting resins is inserted through the manholes into the pipe and then the resin is set ( hardens) through contact with steam or hot water. Inserted by winch in place and invert in place methods. Restrictions and requirements: no additional excavation is required, can be used on non-circular pipes, bends, offsets, and misaligned joints. Useful in pipes needing minor structural reinforcement. A Jointless solution. Has a curing time. Sometimes require flow bypass lots of methods. Options: Resins unsaturated polyester (poly-urethane), vinyl ester, fiberglass epoxy ; Textiles polyester fiber felt
Advantages of CIPP Installation is relatively fast and excavation is not normally required Access is gained through existing manholes The method is versatile and can be tailored to line noncircular sections It can negotiate bends and bridge offsets and missing sections of pipe CIPP can be used for full structural renovation or for thin, hydraulic liners Laterals can be reinstated in non-man-entry lines with robotic cutters Despite a slight loss of diameter, the smooth interior surface may improve flow capacity
Considerations of CIPP The old pipe needs extensive surveying, cleaning, and preparation Bypass pumping is required Pre-grouting may be necessary in damaged areas or where there are voids The liner pipe is flexible and needs support from surrounding material Over and under-cuts at lateral restoration can occur As diameters get larger, costs tend to rise more rapidly because of the weight and cost of material plus the greater difficulty of installation
Types of Coating Method Spray-on Linings (Structural) Spray-on Linings (Non- Structural) Diameter Range, inches Max Installation Length, feet Liner Material 36-180 Various Reinforced cement mortar 3-180 500 Epoxies, cement mortar Application Gravity and Pressure pipelines Gravity and Pressure pipelines
Coating Description: material is applied by spray, trowel, or roller to the host pipe and can be used as a patch or complete rehabilitation Restrictions and requirements: requires a clean dry surface, no loose material in sewer, cure in around 1 hour Options: epoxy, shotcrete, polyester, silicone, urethane, and vinylester. Spectra Shield Sewpercoat
Advantage of Ferro-cement It can easily accommodate noncircular sections and diameter changes Connections are easily incorporated into the relining It can be used in partial flows and precast invert sections can be incorporated The cross-sectional capacity loss is relatively small It is possible to design for pressure line rehabilitation Work can be undertaken from existing manholes
Considerations of Ferro-cement Skilled and experienced operators are needed to achieve the required level of quality The system is not well understood as a rehabilitation technique Spraying is difficult to control Preliminary sealing may be necessary to avoid infiltration
Techniques for Point Repair Method Diameter Range, inches Max Installation Length, feet Liner Material Robotic Repairs 8 30 N/A Epoxy resins, cement mortars Grouting N/A N/A Chemical Grouting Application Gravity pipelines Gravity and Pressure pipelines Link-Sleeve 4 24 N/A Special sleeves Gravity and Pressure pipelines Point CIPP 4 24 50 Resin-saturated fabric tube Gravity pipelines
Point Repair Practices for Collection Systems Technologies Structural Integrity Corrosion Resistance Advantages Grouting Low Good May improve hydraulic characteristics Protects against corrosion Provides soil stabilization around pipe CIPP High Good Able to provide area repair of numerous cracks Grouting Mechanical Sleeves High Good Good application for repairing joint leaks Bypass pumping or system shutdown not required Disadvantages Adds no structural capacity to pipe Equipment intensive operation Bypass pumping or system shutdown may be required Bypass pumping or system shutdown may be required More expensive for small sections Only possible to repair a local area, such as a joint or single large crack
Universal Need for Rehabilitation Liverpool Guatemala Tucson Arizona Chicago Tucson, Arizona
Mount Vernon, WA 05/09 Hudson, OH 03/09 Columbus, OH 01/06 Virginia Beach, VA 01/06 San Francisco, CA 12/06 Location Year Unit Costs for Pipeline Rehabilitation using CIP Technology (Costs Corrected to ENR CCI 8574) Bidders 6" CIP ($/LF) 8" CIP ($/LF) 10" CIP ($/LF) 12" CIP ($/LF) 15" CIP ($/LF) 18" CIP ($/LF) Source Engineer's Estimate $65.22 $86.96 $97.83 $119.57 NA NA K.J. Woods Construction, Inc. $32.61 $32.61 $32.61 $43.48 NA NA Ranger Pipelines, Incorporated $28.26 $27.17 $28.26 $39.13 NA NA 1 JMB Construction, Inc. $36.41 $35.00 $36.41 $50.44 NA NA Engineer's Estimate NA $33.58 $67.16 NA NA NA Suburban Grading and Utilities NA $33.23 $99.34 NA NA NA Peters and White Construction NA $36.94 $38.06 NA NA NA Tri-State Utilities NA $29.10 $83.95 NA NA NA W.R. Hall NA $27.98 $87.87 NA NA NA Engineer's Estimate NA $41.64 NA $55.52 NA NA United Survey, Inc NA $26.86 NA $39.18 NA NA Reynolds Inliner, LLC NA $32.46 NA $35.82 NA NA Insituform Technologies, Inc NA $27.98 NA $41.41 NA NA Kokosing Construction Co. Inc. NA $29.66 NA $41.41 NA NA American Water Survey NA $36.38 NA $58.20 NA NA Kokosing Construction Co. Inc. NA $21.10 NA NA $40.19 NA United Survey, Inc NA $27.13 NA NA $65.30 NA Insituform Technologies, Inc NA $23.11 NA NA $62.29 NA Reynolds Inliner, LLC NA $26.12 NA NA $56.26 NA Engineer's Estimate $28.00 $30.00 NA $34.00 NA NA Columbia Pumping and Construction $31.60 $27.50 NA $49.60 NA NA Insituform Technologies, Inc $30.00 $27.00 NA $31.00 NA NA Michel's Corporation $37.00 $29.00 NA $38.00 NA NA 2 3 4 5
Cement Mortar Pipe / Grouting Description: application of a cement mortar to the inside of pipe line to protect them from corrosion or slip line cement pipe into sewer. Cement mortar coatings can be applied to concrete, steel, or iron pipes, and can extend the service life of a pipe by up to 50 years. The coating is made of one part sulfate resistant cement to two parts sand. The coating is applied by hand or by an automated spreading machine. Options: glass reinforced cement, polymer mortar, HOBAS pipe glass reinforced polymer mortar (CCFRPM) Restrictions: Cement mortar cannot be applied in pipe networks with many bends, or in very cold regions.
In-Situ Liners / Modified Cross Sectional Liners Description: A soft liner is impregnated with a glass reinforced polyester laminate; this is pulled through the damaged drain run and molded rigidly in place by water or air pressure. Restrictions and requirements: pipe must be relatively clean to create tight seal. Existing leaks must be properly repaired. Only acceptable in pipes larger than 48 inches Options: preformed strips (PVC) - strips and grout constitute their own structural system, geo-membrane sheets (HPDE) require access pits they are attached with anchor bolts to sewer, geo-membrane panels (HPDE) require anchor studs and space is filled with cementous grout
Example Unit Costs Sewer Rehabilitation using Cured-In-Place (CIP) Technology (Unit Costs Corrected to ENR CCI 8574) Date 2006 Cost Range CIP Products Assuming a 50-foot lateral with moderate root intrusion INFlex Liner $16.59 - $55.31 Formadrain $77.43 - $138.27 Inserv $66.37 - $70.8 MaxLiner $77.43 - $110.62 PermaLateral $82.96 - $165.93 Primeliner $16.59 - $77.43 Verline Lateral $44.24 - $82.96 TOP HAT $17.7 - $26.55 PrimeLiner LC $11.06 - $22.12 Insituform Lateral $33.19 - $88.49 LMK T-Liner $77.43 Source Methods for Cost Effective Rehabilitation in Private Lateral Sewers: Final Report. 2006. Water Environment Research Foundation.
Fold and Formed Cont d
CIPP Cont d Grouting sleeve a type of CIPP Description: the pipe at a reduced diameter is sent down the pipe and expanded in place. Grout expands and penetrates the cracks and the stainless steel core completes the restoration. Resin Textile Grouting Sleeve