290 likes | 456 Views
NeoPoxy 50-Year Design Life Structures Using Traditional Materials. An engineering guide for economical long-life rehabilitation and protection. David H. Johnson, NeoPoxy Corp. What Are The Problems?. Hydrogen Sulfide/Sulfuric Acid Attack Reduced I&I is lowering flow rates
E N D
NeoPoxy 50-YearDesign Life StructuresUsing Traditional Materials An engineering guide for economical long-life rehabilitation and protection. David H. Johnson, NeoPoxy Corp.
What Are The Problems? • Hydrogen Sulfide/Sulfuric Acid Attack • Reduced I&I is lowering flow rates • Acid generation is increasing • Deterioration rate is rapidly increasing • System investment is being lost
What Are The Solutions? • Cement relining • Bag liners • Mechanically locked PVC • Polyurea & Polyurethane • PureEpoxy Lining Systems
34 Foot Structural Liner – One of 43 Manholes – Why Use A 50-YearPureEpoxy Structural Design? • Eliminate Failures • Enhances Host Structure • Delivers Long-Term Value • 25-Year Proven Design • 50-Year Materials Experience
Why Use PureEpoxy Liners? • Monolithic Protection • No annulus • Impervious to H2S • Unaffected by Caustic or Acid • ASTM Design-Compliant
Why Use An ASTM Design? • 25-Year Reliability • No Corrosion Failures • No Structural Failures • Conservative, Predictable & Safe • ASTM – An International Standard
ASTM F1216Wall Thickness Design • P = groundwater load • k = enhacement factor • EL = long term flexural modulus • v = Poissons ratio • SDR = standard dimensional ratio • C = ovality reduction factor • N = safety factor ASTM F1216-98 “Partially Deteriorated” Design Formula Thickness increases with load Epoxy’s Recognized Bonding Characteristics Provides A Massive Safety Factor
Partially Deteriorated Design NPR-5300 ASTM F1216 Wall Thickness vs.. Hydrostatic Load Wall thickness design increases from 0.25” after the water table is reached
Typical 4’ IDManhole Wall Thickness 0.25” (250 mils) Avg. Water Table Increasing Thickness With Greater Load 10’ of water= 0.44” 20’ = of water 0.55” 30’ = of water 0.63”
Recognized Corrosion Resistance Requirements • 10% Sulfuric Acid • 5% Nitric Acid • 10% Phosphoric Acid • Gasoline • Tap Water ASTM F1216-95 City of Los Angeles* • 31% Sulfuric Acid** • 5% Sodium Hydroxide • 5% Ammonium Hydroxide • 1% Nitric Acid • 1% Sodium Hypochlorite *121 days in full Immersion – ** 700% LOWER than pH-1 NPR-5300 Epoxy EXCEEDED All Corrosion Performance Requirements
County Sanitation Districts of Los Angeles Manhole Test “NeoPoxy NPR-5300 Series in Acid Vat C97 was inspected on 12/8/03 after 5 months exposure to 10% H2SO4. So far, there is no color change or evidence of any problems. The test will be completed in about 7 more months.” County Sanitation Districts of Los Angeles County
PureEpoxy Liners100% Solids, No VOC’s No Solvents Low Odors No Shrinkage Moisture Tolerant Cures Underwater Environmentally Friendly
The Solution That Works DIRECT-TO-AGGREGATE BONDING
Direct-To-Aggregate Advantages • Cement is the “weakest link” of manhole materials. Smooth with cement minimally in joints & larger holes. • Direct-To-Aggregate bonding is the strongest, most reliable design. Like sandblasting, it increases surface area and increases pull-off strength.
Bonding To Aggregate • Aggregate Does Not Corrode • Perfect Adhesion Surface • Deeply Anchored • 3-D Encapsulated Aggregate • Atomic-Level Chemical Adhesion • Perfect Bond & Seal Insures that minor cleaning issues do not impact 50 year service life
Groundwater Design & Benefits • Bonded Beam Design • Flexural Modulus Driven • Adhesion Is Greater Than Strength of Substrate • Cannot Peel • Cannot Blister • Cannot Buckle
Force Water Load Bearing 462’ Water Head Assumption: One square inch aggregate spacing AND no adhesion to mortar. Fact: The minimum force to pull off one square inch of embedded aggregate is 200 psi or 462 feet of hydrostatic head.
Mechanical Benefits • Impact Tolerant • Aggregate Protects Substrate • Scratches & Nicks Rarely Reach Cement • Aggregate Acts As Corrosion Restrictor • Any Damage Easily Field Repairable
Insert Pipe New Pipe Connections Break through concrete 1) Cut hole 2) Seal against any incoming water 3) Finish With Epoxy Seal
Finished Additional Pipe Connections Seal Connection With Epoxy 1) Cut hole 2) Seal against any incoming water 3) Finish With Epoxy Seal
SIMPLE and Reliable! Preparation & Lining • Preparation & Lining • Water Blast @ 3500-5000 psi • Confirm Surface pH of 6 - 9 • Fill & Patch With Cement or Epoxy • Apply 250 Mils Epoxy Liner * Direct To Aggregate
How Does Ambient Cure Epoxy Improve Long-Term Performance? Thermal coefficient of expansion and contraction causes heat cured materials to contract during cool down. Ambient cure epoxy stays physically “tuned” to the substrate for maximum adhesion and a 50-year life expectancy. No annulus for an H2S penetration path.
Chimney Seal Epoxy • 500% Elongation • Traffic Loads OK • Freeze-Thaw OK • Joints & Seams OK Permanently stops infiltration at rings, seals & moving joints. One step process
Significant Design Points 50-Year Designs are the most economical, reliable rehabilitation solutions. Third Party testing combined with an ASTM design insures that liners perform throughout their 50-year design life. Direct To Aggregate bonding is the strongest, best long-term solution for a conservative 50-year design life.
Cost/Benefit Advantages Mobilization Costs remain the same as for most other methods. Only material costs change, and for only a small percentage increase you get solid protection 50-Year Design provides reliable assurance of performance Lowest Lifetime Maintenance Cost Preserves System Investment
Other Great NeoPoxy Products • Potable & Wastewater Pressure Lining Systems • Heat & Chemical Resistant Epoxy to 300°F • Environmental Epoxy for Sewer & Storm Drains
Thank you! Thank YOU! …for letting us discuss PureEpoxy rehabilitation and protection. www.NeoPoxy.com (925) 560-1500
Photo Collection of Works www.NeoPoxy.com (925) 560-1500