Culvert Repair Using Geopolymer Mortars

CONCRETE PRESERVATION ALLIANCE

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Working together to promote education and awareness of concrete repair industry standards, new and innovative corrosion prevention technologies and sustainable construction practices.

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OUR MEMBERS

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Garth Fallis, P.Eng.

Garth is a Professional Engineer and recently retired after 40 years with Vector Construction. Garth graduated from the University of Manitoba with a Bachelor of Science in Civil Engineering 1976. He joined Vector in 1981 on Vector’s first concrete rehabilitation project at the Seven Sisters Generating Station and has since held a variety of Management and Executive positions.

He is still active with International Concrete Repair Institute (ICRI) and on several committees including the Strengthening and Stabilizing Technical Committee. He also serves on several committees for American Concrete Institute (ACI) including ACI 562 Concrete Repair Code Committee, ACI 423, ACI 440, and ACI 549. Garth is also actively involved in the Post-Tensioned Institute (PTI) where he was chair of the DC-80 Repair and Rehabilitation committee. In recognition of his contributions to these organizations, Garth has been given the honor of being named a Fellow of ICRI, ACI, and PTI.

Culvert Repair Using Geopolymer Mortars

• Structural repair of culverts versus replacement

• Spray-applied geopolymer liner design and installation

Webinar Topics

• Culvert and Pipe Repair Methodologies• What is a Geopolymer• Geopolymer Properties and Testing• Material Demonstration• Design Methodology• Case Studies

Culvert and Pipe Repair Technologies

• Remove and Replace – Open Cut• Culvert within a Culvert• Slip Lining• Cured in Place Lining• GFRP sectional Liner• Spray Applied Lining

Remove and Replace – Open Cut

Culvert within a Culvert

Culvert within a Culvert

Slip Lining

Cured in Place Lining

GFRP Sectional Liner

Spray Applied Lining

Structural Rehabilitation of Pipes - CentrifugalCasting Concrete Pip (CCCP) / Spin Casting of Geopolymer (SCGP) using Geopolymer

• Rapidly distributes material within the pipe’s internal circumference

• Forms a strong, low permeability, cementitious type lining

• Depending upon design & thickness, creates a “pipe within a pipe” and does not rely on the integrity of the host structure

• While not generally required, it is compatible with most common reinforcement technologies

What is a Geopolymer?

• Not a Plastic• Not HDPE/PVC/Epoxy

• Looks and feels like a cementitious material

• Workability• Material Properties• Service Life

• Chemical structure like natural stone• Monolithic• Durable• Corrosion Resistant

Chemistry Primer: OPC vs. Geopolymers

Typical Geopolymer StructureTypical Hydrated OPC Structure

Not all Geopolymers are the same!!

• Flexural Strength• ASTM C78 vs ASTM C293

• Laboratory Testing with Published Results• Very few geopolymers have laboratory testing with results published in peer reviewed

journals (the criteria for use in Industry Standards and Documents, i.e. ACI )

• Design Methodology• Very few geopolymers have a design methodology that has been derived from laboratory

testing

• Self Bonding Capabilities• Very few geopolymers have self bonding data based on laboratory testing

• Length of History and Field Installations

GeoSprayTM Geopolymer MortarEngineered

• 1st Just-Add-Water geopolymer system• Designed for horizontal pipes• Pumpable to 500 feet

Tested• EPA Evaluated• Extensive 3rd party research• Thorough in-house testing by Milliken

Research Corporation

Safe• Unlike CIPP, it is Styrene FREE• Contains no leachable toxins. • Passes EPA TCLP Toxicity Characteristic

Leaching Procedure.• Passes NSF 61: Suitability for Potable Water

GeoSpray™ geopolymer is a unique high performance fiber reinforced mortar for structural pipe rehabilitation.

GeoSprayTM Geopolymer Mortar

ASTM for Flexural StrengthASTM C293

3.1 This test method is used to determine the modulus of rupture of specimens prepared and cured in accordance with Practices C31/C31M or C192/C192M. The strength determined will vary where there are differences in specimen size, preparation, moisture condition, or curing.

3.2 The results of this test method may be used to determine compliance with specifications or as a basis for proportioning, mixing and placement operations. This test method produces values of flexural strength significantly higher than Test MethodC78/C78M.

C78 is the ASTM Test of Choice because it is for flexural strength and more representative

ASTM C78

3.1 This test method is used to determine the flexural strength of specimens prepared and cured in accordance with Test Methods C42/C42M or Practices C31/C31M or C192/C192M. Results are calculated and reported as the modulus of rupture. For the same specimen size, the strength determined will vary if there are differences in specimen preparation, curing procedure, moisture condition at time of testing, and whether the beam was molded or sawed to size.

3.2 The results of this test method may be used to determine compliance with specifications or as a basis for mixture proportioning, evaluating uniformity of mixing, and checking placement operations by using sawed beams. It is used primarily in testing concrete for the construction of slabs and pavements

Geopolymer Advantages – Self BondingGeoSpray will not have cold joints like other cementitious productsExperimental Parameters:On Day 1:• Series of 2” by 4” cylinders were cast

half full and cured on ~ 45 angle.On Subsequent days (1, 7, 14 and 28):• Top half of the cylinders were cast and

filled creating a 45 angled joint in the center of each cylinder

Compressive strength tests were conducted 28 days after the top half of the cylinders were cast.

Joint in Tested Sample

Geopolymer Advantages – Self BondingResults:• Samples cast of GeoSpray did not break at

the joint when tested under compression• The chemical nature of GeoSpray allows for

chemical bonding across the interface even with pours 28 days apart resulting in a monolithic structure.

• Samples cast of competitive cement mortars always broke along the angled joint essentially creating 2 separate layers.

This unique property of geopolymers allows project flexibility in variable weather conditions as the covalent bonds prevent cold joint shear failure

GeoSpray

Portland-Based Competitor

Material Consistency for Spraying

Spraying and Hang-ability

Spray Hanging on Plastic

Demo for Manholes

Spraying for Vertical Applications

Finished Surface for Vertical Application

Demo Setup for Culvert Spray Lining

Demo for Culvert Spray Lining

Spray Lining First Layer Half Completed

A New Pipe Within An Old Pipe

GeoSpray Application on Leaking Culvert

Design MethodologyBasic AssumptionsMR>MA

Moment MR=I*SF/cI = t3/12

But do we really know where the neutral axis is?It is more conservative to assume that it is not at the mid-point of the liner but at the interface so we will assume c=t

Moment = t2*Sf/12EL – Elastic ModulusSF – Flexural StrengthST – Tensile StrengthN – Safety FactorC – Ovality Reduction Factor (ASTM F-1216)P – Total Loadμ – Poisson's Ratio

Design Methodology

MR=MA

M = t2 *SF /12 = 0.0062*P r2

The resultant solution for this case is:

Where: N – Safety FactorC – Ovality Reduction Factor

Research for Design Methodology: La Tech TTC Design Model TestingExperimental OutlineThe goal of the project was to validate proposed engineering methodologies for structural rehabilitation of large diameter pipes with experimental data.

This study tested the effects of:• Liner Thickness • Pipe Diameter (24” – 48”)• Ovality• Pipe Type (RCP, CMP, Cardboard)

All RCP pipes were pre-broken prior to repair.

La Tech TTC: Experimental Parameters

• The pipes were then rehabilitated using GeoSpray geopolymer via a spin casting method

La Tech TTC: Experimental Parameters

• The experimental apparatus included the ability to use video monitoring of the shear stresses in the structure during loading

La Tech TTC: New vs Rehabilitated CMP Curves

La Tech TTC: Model 3 – Circular Arch with Beam Load

The resultant solution for this case is:

M = 0.0062*P r2 = t2*Sf /12

Dovercourt Corrugated Steel Pipe Culvert Rehab

1354 Dovercourt Rd, North Vancouver

• Culvert entry and exit retaining walls are connected to surrounding properties and landscaping, making a traditional removal and replacement approach a costly, logistical nightmare.

Site Set up / Environmental Protection

Culvert Invert Repairs

Patch Repair Culvert Invert

Patch Repair Culvert Invert

Installation of GeoSpray Liner

Installation of GeoSpray Liner

UARP Roadway Improvement ProjectSacramento Municipal Utility District

Overview of Location/Conditions

Repair of Invert Before Lining

Set Up for Install

Completed Lining

Vernon Creek Culvert No. 3 RehabilitationVernon, British Columbia

Overview of Location/Conditions

Dewatering System

Chemical Grouting

Spraying

Completed Lining

Agimac Lake Culverts Corrugated Metal Pipe (CMP) Culverts

Ignace, Ontario

Before

Cofferdam

Spraying

Spraying

CompletedLining

QUESTIONS?

Contact Garth

Garth Fallis, P.Eng.Vice-President Construction TechnolgiesVector ConstructionWinnipeg, MB

GarthF@Vector-Construction.com

WEBINAR RECORDING & FUTURE EVENTS

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