Embed Size (px)
Citation preview
Pr
ec
as
t
/
Pr
es
tr
es
se
d
Co
nc
re
te
B
ri
dg
e
De
ck
S
la
bs
TR
AN
SP
OR
TA
TI
ON
S
TR
UC
TU
RE
SGreat Bras D’or BridgeDeck ReplacementV i c t o r i a C o u n t y , N o v a S c o t i a
Focus onPrecast Concrete Solutions
website:e-mail: Strescon is a member of the OSCO Construction Group
C o r p o r a t e O f f i c e400 Chesley DrivePO Box 3187Saint John, NB E2M 3S3Phone: 506-632-2600Fax: 506-632-7689
N e w B r u n s w i c k P l a n t101 Ashburn RoadSaint John, NB E2L 3W2Phone: 506-633-8877Fax: 506-632-7576
N o v a S c o t i a P l a n t131 Duke StreetPO Box 44205Bedford, NS B4A 3Z8Phone: 902-494-7400Fax: 902-494-7401
N e w E n g l a n d O f f i c e25 Burlington Mall RoadBurlington, MA 01803Phone: 781-221-2153Fax: 781-221-2155
The Great Bras D’or (Seal Island) BridgeLocated in Cape Breton, Nova Scotia on the Trans CanadaHighway 105, the main crossing over the Great Bras D’or toIndustrial Cape Breton. This vital stretch of highway also leads tothe only ferry connection to Newfoundland from North Sydney. In the late 1990s the bridge deck had deteriorated to a point wherethe cast-in-place slab, which was replaced 10 years prior, wasapproximately 75% delaminated. A major deck replacementprogram was required. The engineering firm of CBCL was hired to do a comprehensivestudy of the bridge and come up with a method of replacing theexisting deck without severely affecting the traffic flow. Afterreviewing a number of options, Precast Prestressed concrete deckslabs were chosen as the best replacement system for manyreasons.1.) The high performance Precast concrete deck slab systemis much more durable than conventional systems.2.) Prestressed Post-tensioned deck slabs offer superior crackcontrol under service load conditions.3.) The system chosen for this project is significantly lighter thanconventional cast-in-place concrete deck systems, minimizing theload effects on the existing steel structure, thus reducing theamount of truss reinforcement required.4.) Construction could be carried out with minimal trafficdisruptions as the bridge could remain open to single lane traffic.
The project consisted of removing the existing bridge deckone lane at a time. Reinforcing the existing bridge trusssystem to meet current bridge design codes. Replacing theexisting deck with high performance, precast concrete deckslabs, Prestressed in the transverse direction. The deck slabswere subsequently post-tensioned in both directions afterplacement. Composite action between the precast deck andthe supporting structure was achieved by welding nelsonstuds to the stringers through ports provided in the precastslabs.
Project: Great Bras D’or Bridge Crossing Deck ReplacementVictoria County, Nova Scotia
Structural Consultants: CBCL Limited - Halifax, Nova ScotiaConstruction Manager: All Steel Coatings Ltd.
Port Hastings, Nova ScotiaPrecast Fabricator: Strescon Limited - Bedford,NS
Recipient of the“Lieutenant Governor’s Award
for Engineering Excellence”in Nova Scotia
Design Award winnerStructural Innovation Category
Pr
ec
as
t
/
Pr
es
tr
es
se
d
Co
nc
re
te
B
ri
dg
e
De
ck
S
la
bs
TR
AN
SP
OR
TA
TI
ON
S
TR
UC
TU
RE
S
The project was broken up into three phases. The firstphase was a demonstration phase intended to allow forminor modifications to optimize constructability duringsubsequent phases. Phase one was awarded to All SteelCoatings in 2001 and consisted of 42 deck slabs and 40sidewalk curbs. The progression of the project exceededeveryone’s expectations and the Nova Scotia Departmentof Transportation gave the green light to proceed with thedesign of phase two. Phase two was awarded to All SteelCoating in 2002 and consisted of 168 deck slabs and 160sidewalk curbs. Again everything went well and thedesign of phase three was completed. Phase three wastendered in 2003, and again All Steel Coatings wasawarded project. This final phase consisted of 194 deckslabs and 192 sidewalk curbs. The total bridge deck isnow replaced, on time and on budget. Precast PrestressedPost-tensioned deck slabs have proven to be a state of theart bridge deck system which can be utilized on bothconcrete and steel structures.
