The document summarizes an inspection report of an underground tunnel structure in Montreal. It describes the major structural components, materials used, current conditions, deterioration over time, recommendations from previous inspections, and suggested repair and testing methods. The structure is in critical condition with extensive cracking, corrosion and rebar exposure. Immediate attention is needed on retaining walls, ceiling cracks and rebar corrosion. Non-destructive and destructive testing is recommended to further evaluate the deterioration and inform repair methods. Annual inspections should continue to monitor the condition.

1. Group 4 :
Christy Jesurajah, Lloyd Linton 260429440
Masi, Michael 260379971
Moradi, Milad 260399628
Pakpour, Farbod 260298074
Torikian, Aram 260429332

2.  Structure : 81-5159 : Clark Street/ Van Horne Tunnel underpass
 Ownership/Responsibility: City of Montreal (Municipal)
 Major and minor Structural components:
 36 Beams : single span, running along the width of the underpass
 Walls
 Deck
 Retaining walls
 Overpass
 Elevated Sidewalk
 Parapets
 Drainage Systems : middle of the tunnel near the side walls.
 Bike Path
 NJ barrier
 Lights on side walls.
 Materials Used:
 Concrete
 Asphalt
 Steel

3.  How is the structure used:
 2 lanes for traffic
 2 lanes for bikes
 1 pedestrian elevated sidewalk
 No weight restrictions
 Height restriction of 4.40m
 Conditions exposed to:
 Car exhaust
 De-icing salts
 Freeze-thaw
 Vandalism: Graffiti
 Water runoff
 Water accumulation due to
inadequate drainage

4. DATE COTE DE DÉTÉRIORATION RANKING
February 13 2007 18.7[1] ---
October 3 2011 53.0[2] # 41[4]
October 3 2012 108.0[3] # 13[5]
History of Inspections:
Deteriorated very quickly
over the past couple of
years!
Recommendations after 2012 inspection [6]
• Prior records
81-5159 Pont d’étagement
Avenue Van
Horne/ Rue Clark
108 Critique (1) Passées
-Correction les éléments de dispositif de retenue (Debut 2013)
En Cours
- Aucune action en cours
Future
- Élbaoration d’un projet de réfection de la structure

5. High Priority Concern #1 : Retaining Wall
Video :
 Exposed Rebar
 Extreme Corrosion of rebar
 Softening of Cement paste

6. High Priority Concern #2 : Wide Cracks on Ceiling
 Exposed steel
reinforcement
 Severe
concrete
spalling

7. High Priority Concern #3 :
Excessive rebar exposure and corrosion
 Severe exposed Steel
Reinforcement
 Visible corrosion damage

8. Efflorescence

9. Damage at joints
Damage to the pave way

10. Concrete Spalling and Exposed Steel Reinforcement
 Miscellaneous visible corrosion damage

11.  Findings confirm the inspection report.
 The tunnel is in critical condition.
 Three regions that require immediate
attention:
 Retaining Walls
 Wide Cracks on Ceiling
 Excessive rebar exposure and corrosion

12.  Three possible Non-Destructive Testing Methods
 Schmidt Rebound Hammer
 Windsor Pin
 Windsor Probe
 The group recommends using the
Schmidt Rebound hammer,
as it is the easier one to use.
 Furthermore, The Windsor Pin and Probe are sensitive to
carbonation (which the structure is exposed to from daily
traffic)

13.  The group recommends using
coring as a cored sample may be
tested for its compressive strength
from which the flexure, tensile and
shear strength can then be
determined.
 From the non-destructive tests, the
relative difference in strength
between multiple points of interest
will be obtained.
 Locations with the highest relative
strengths will then be selected for
coring purposes.
 Using the measured strength of the
cored samples, a correlation can be
developed which will allow a better
estimation of the strength at
different locations.
Possible Destructive Methods: Coring, Pullout and Break-out Tests

14.  Half Cell Electrode and
Pachometer
 These methods are
recommended as they
determine the location and
assess the condition of the
existing steel reinforcement as
well as the corrosion potential.
 Impact Echo
 Less prone to human errors
 No transmitters required
 No need to determine
shape/support factors
 No need for expensive
radioactive methods
http://www.injectionsolutions.com/Impact%20echo%20ph
otos%20001cropped.jpg
Half Cell Electrode

15.  Phenolphthalein Test
 Determines acidity and
carbonation via color change
 Help determine potential
Acid Attack and/or
Carbonation
 Uranyl Acetate
Florescence
 Detects Alkali-Silicate
Reaction (ASR)
 The chemical solution
bonds with the ASR gel
and glows under UV light

16.  Moisture Content Meter
 Affected by chlorides
 Surface Resistivity Meter
 Sensitive to chlorides
 Sensitive to carbonation
 Initial Surface Absorption Properties and Figgs
absorption
 Poroscope
 Semi-destructive
As the underpass is exposed
to CO2 and chlorides, these
two are eliminated as the
results from these test may
be misleading.
Requires a lot of preparation (lab + field)
Despite being semi-destructive, the
group suggests using a Poroscope .

17. Method Justification
Affected
Members
Partial Depth Removal using 15#
Pneumatic Chipping Hammer of
Concrete.
•Extensive cracking and corrosion
of the steel rebar and its affect on
surrounding concrete
•15# Hammer is light enough to be
used on overhead surfaces.
•Practical for removal of sulphate
attacked concrete.
•Tunnel Ceiling
•Retaining Walls
Replace corroded steel
reinforcement
•Extensive corrosion damage
Overhead Concrete replacement
using Form and Pump Technique
•Efficient pumping
•Good for overhead repair Tunnel Ceiling
Side wall concrete replacement
using Form + Cast-in place
Technique
•Simple method
•Common construction practice
•Good for vertical surfaces
Retaining Walls
 Most of the deterioration damage of the
underpass is caused by Sulphate or Corrosion
 Preventive Measures
 Installation of sacrificial anodes to prevent future corrosion damage.
 Use concrete with low C3A to minimize future sulphate attack

18. Method Justification Affected Members
Concrete removal :
Pneumatic
Chipping Hammer
•Simple and cost effective
•Easy to use
•Ceiling
•Side walls
Concrete Patching:
Trowel
•Use to patch small
affected areas (pop-outs)
•Easy and Efficient for
small areas
 Patching of Concrete in ASR deteriorated areas.
 Preventive Measures
 Lithium treatment is not recommended due to cost.
 Inspect and monitor patch work instead

19. Type of Repair Remediation
Method
Justification Affected Members
Crack Repair Rout and Seal •Simple
•Cost and labour
effective
•Beams
•Side walls

20. Type of
Repair
Potential
Remediation
method
Advantages Disadvantages Final
Recommendations
Carbonate
Damage
Repair
Realkalinization •Restores pH
balance of the
concrete
•Extends service life
•Requires
specialised labour
force
•High cost of
material
•Since the cost of
renovation exceeds
the risks of damage,
we recommend
withholding any
remediation
techniques.
•However, actions will
be taken if the
situation changes.
Chlorides
Damage
Repair
ECE •Restores
passivation film
•Extends service life
 Preventive Measures : Annual inspection to monitor
and assess damage.

21.  Inspection strategy
 Continue Annual Inspections
 City of Montreal
 Interim Inspection
 Inspections on repaired members
 Chloride and carbonation damage

22. 1) Inspection report from 2007
http://ville.montreal.qc.ca/pls/portal/docs/page/transport_v2_fr/media/documents/81_5159_
Inspection_generale_2007_02_13_web.pdf
2) Inspection report from 2011
http://ville.montreal.qc.ca/pls/portal/docs/page/transports_fr/media/documents/81-
5159_inspection_generale_2011-10-03.pdf
3) Inspection report from 2012
http://www.ville.montreal.qc.ca/pls/portal/docs/PAGE/M_CHANTIER_FR/MEDIA/DOCUME
NTS/PONTS_ET_TUNNELS/PONTS_ETAGEMENT/81-
5159_inspection_generale_2012-10-03.pdf
4) Ranking 2012
http://ville.montreal.qc.ca/pls/portal/docs/page/transport_v2_fr/media/documents/2012_Tabl
eau_587_structures.pdf
5) Ranking 2013
http://ville.montreal.qc.ca/pls/portal/docs/page/m_chantier_fr/media/documents/statut_fonct
ionnel_589_structures.pdf
6) Tableau Synthese
http://ville.montreal.qc.ca/pls/portal/docs/page/m_chantier_fr/media/documents/tableau_sy
nthese_24_structures.pdf
7) CIVE 527 Lecture Notes, McGill University, Fall 2013
8) Impact-Echo
http://www.injectionsolutions.com/Impact%20echo%20photos%20001cropped.jpg