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Debarment HearingConcrete Restoration Services Ltd.

Bid Opportunity 524-2009

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Recommendation:

• Debar Concrete Restoration Services Ltd. (CRS) for a three year period from acting as contractor, sub-contractor, or supplier to any person who is awarded a contract with the City of Winnipeg.

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Notice of Default issued on Sept. 21, 2012

Pursuant to C18.1(f) & C18.1(l)CRS failed to remedy defects or deficiencies and failed to comply with an order given by the Contract Administrator

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C18.1 An event of default will have deemed to have occurred if the Contractor:

(f) fails to remedy defects or deficiencies during the warranty period in the manner and within the time frames specified by the Contract Administrator;

(l) refuses or neglects to comply with an order given by the Contract Administrator;

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On Sept. 13, 2012 CRS acknowledged in writing they refused to undertake repairs during warranty period indicating:

“CRS and Transpo Industries will not accept any liability to provide restorative or remedial action as has been requested by the Contract Administrator….”

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Cannot allow Contractors to refuse to follow Contractual instructions.

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Pursuant to C13.8 if the Contractor disagrees with a determination they shall nonetheless comply with the order and may appeal concurrently.

Failure to comply resulted in an event of default and a serious breach of Contract.

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Warranty Work pursuant to Clause C13.8:

If a Contractor disagrees with the Contract Administrator’s determination under C13.6, he shall nonetheless comply with C13.7. The Contractor may concurrently appeal the determination of the Contract Administrator as provided in C21.

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Event of Default resulted in the City taking control of the Work to correct unsafe conditions caused by the debonded overlay.

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Overlay status:

• 19% debonded in 2012. Repaired by City in 2013 at a cost of $26,682.85.

• 48% debonded in 2014 and was removed by City forces.

• Remaining 33% has several areas where overlay has worn through to concrete.

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Five Year Warranty

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Exceptions to the Warranty Agreement relate to the condition of the concrete deck.

There is no evidence these exceptions exist on the concrete deck.

The concrete deck is in good condition.

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Onus is on Contractor to prove the exceptions exist.

Due diligence would have required on-site visual assessment and extraction of cores to test concrete properties such as strength, hardened air void, permeability, and chloride content.

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Observed Overlay Defects

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Debonding occurred at the interface of the overlay and the concrete deck.

Cracking has occurred within the overlay.

No waterproof seal in other localized areas due to premature wear through overlay.

Inadequate overlay thickness in localized areas. Specified thickness is 8 mm.

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Widespread debonding the result of localized cracking/debonding followed by wet conditions and traffic causing larger areas to shear off and debond.

Concrete residue identified on the debonded overlay is fraction of mm thick and the result of the shearing process or debris from the surface preparation process.

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Cracking and premature wear the result of a resin rich overlay due to aggregate seeding deficiencies.

Aggregate seeding deficiencies were identified at time of construction. During Appeal #1 CRS advised these areas would perform which is not the case.

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Aggregate Seeding DeficienciesBlack areas are resin rich. Aggregate did not have aggregate bond into the resin.

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Typical Overlay Debonding

Note original deck tyning still in tact.

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Typical Overlay DebondingNote original deck tyning intact.

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Debonding with bubbling

Note straight debond line at interface of placement.

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Typical Transverse CrackingOverlay was still bonded.

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Typical Gauge Rake Gouging

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Insufficient Overlay Thickness

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Insufficient Overlay ThicknessPossibly caused by premature wear.

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Premature Overlay WearNote overlay has worn through to the concrete.

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Premature Overlay WearPossibly caused by mechanical damage as a result of originally rough surface.

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Premature Overlay Wear 2014Note several locations where overlay has worn through to concrete.

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Premature Overlay Wear 2014Up close view of worn through area.

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Localized Deck Condition 2014Curb lane in area of debonded overlay.

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Typical Underside of Debonded OverlayBlack areas are clear resin.

Grey areas are concrete residue.

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Typical Underside of Debonded OverlayCloser view

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Typical Side View of Debonded OverlayNote thin residue thickness.

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Concrete Deck• Constructed in 2002

• Initial set retarded but 28 day strength exceeded design requirements

• Initial scaling in the first winter resulted in extensive testing and inspection for 5 years.

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Concrete Deck (cont’d)

• Testing included compressive strength, air voids analysis, chloride content, permeability, petrographic examination, and chemical analysis.

• Annual visual inspections for five years.

• Concluded concrete was in the normal range.

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Concrete Deck (Cont’d)

• To date there is no evidence of concrete disintegration, spalling, or cracking as a result of structural movements.

• No cores or relevant concrete testing has been undertaken to determine that a Warranty exception exists.

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Bond Testing

• Surface preparation measure according to :– B.O. 524-2009– Transpo T-18 Technical Data Sheets– Every other reference we could find.

• Not a method for determining the quality of the concrete.

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E3.3.1 Surface Preparation(f) The acceptability of the surface preparation will be determined by a vertical axis pull bond test. This test involves the bonding of a 64 mm diameter steel disk to the prepared substrate, using a fast- setting epoxy, and it’s removal from the substrate by applying a vertical pull.

(g) Substrate preparation will be approved if at least 75% of the bonded steel disk surface is covered with

substrate concrete exceeding 3mm in depth. The frequency of this test is at the discretion of the Contract Administrator…

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CRS states bond test value must be ≥1.7 MPaThis is not supported by:

• BO 524-2009• Transpo T-18 Technical Data Sheets• ACI-503R• ACI-548.8-07• ACI-548.9-08M3• ACI-548.10-10• ASTM C1853

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Previous documents identify a minimum value for the resin not the substrate.

Basic Engineering Premise:

The adhesive should be stronger than the substrate it is bonding.

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AASHTO-AGC-ARTBA – Task Force 341995 Guide

Indicates 1.7 MPa or failure at a depth of 6mm.

Similar to Contract specifications in that a significant matrix of concrete needs to be pulled for the test to pass; not just residue to have a failure in the concrete.

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Eng-Tech Bond Test/Report

• CRS indicated areas were shot-blasted prior to testing. No evidence to support this claim.

• Only 2 tests were directly on concrete both of which met specification/guideline criteria.

• Tests 1, 2, & 6 identify failure in concrete but no failure depth identified nor is it support by photos of the core locations.

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Bond Test 3 = 1.8 MPaOn Concrete.

Note depth of failure. Debris in hole.

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Bond Test 4 = 1.0 MPa On concrete. Meets all specifications & guidelines.

Note the rough fracture surface.

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Bond Test 5 = 0.88 MPaOn overlay.

Clear failure in overlay.

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Bond Test 1 = 1.3 MPaReported as 75% failure in concrete substrate.

Fracture surface does not support report finding.

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Bond Test 2 = 0.82 MPaReported as 75% failure in concrete substrate.

Fracture surface does not support report finding.

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Bond Test 6 = 0.54 MPaReported as 100% failure in concrete substrate.

Clear error. Tyned surface still visible.

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END