Costco has very strict requirements for their warehouse floors that they must be crack-free to minimize maintenance costs and ensure a quality customer experience. For their new Port Coquitlam warehouse in Canada, the concrete supplier Rempel Bros developed a special mix called PerformX CrackGuard using Grace Construction's Eclipse admixture to meet Costco's stringent less than 0.032% shrinkage requirements. The PerformX CrackGuard mix performed extremely well with virtually no cracking observed, even after saw cuts were made in one section, demonstrating its ability to minimize shrinkage cracking. Both Costco and the contractors were satisfied with the performance and cost savings of the new concrete mix.

1. No cracks for Costco warehouse with
an exacting slab installation
Costco members expect to find every-
thing from food and clothing to autos
and tires at wholesale prices in the
company’s warehouse stores. What
they do not expect—and will not
find in the future—are cracks in the
concrete floors.
Some shrinkage cracking is a fact
of life in the construction of most
concrete floor slabs, but Costco’s new
warehouse in Port Coquitlam, British
Columbia, Canada, has virtually
none. That is because the concrete
used a mix developed by local supplier
Rempel Bros. Concrete Ltd., incorpo-
rating Grace Construction Products’
Eclipse®
admixture.
Costco’s corporate mission is to keep
operating costs to an absolute mini-
mum and that means designing and
building retail outlets with utilitarian
finishes. Floors are concrete, but
Costco insists that they be the best
possible concrete.
For the past 15 years Mulvanny
Architects have designed new ware-
houses for Costco. Mulvanny has
developed and refined a 17-page
floor specification, said Mulvanny
senior project manager Brent Walton.
“Concrete shrinkage cannot exceed
0.032 per cent at 28 days,” said
Walton. “That’s less than 3/8 of
an inch in 100 feet.”
P R O J E C T P R O F I L E
“It’s very important to us to
achieve superior appearance and
durability. But the bottom line
is cost savings to our members,
both in terms of initial cost
and lower maintenance costs
in the future.”
Ali Moayari
Vice-president
construction at Costco
Port Coquitlam Costco Warehouse
CrackGuard
™
APerformX™
SeriesMix
Project Profile - PerformX 10/4/99 11:54 AM Page 1

2. Project Credits:
Project: Costco Wholesale Store, Port
Coquitlam, British Columbia, Canada
Architects: Mitchell C. Smith and
Mulvanny Architects, Bellevue,
Washington
Structural Engineer: Engineers North
West, Seattle, Washington
Readymix Concrete Supplier: Rempel
Bros. Concrete Ltd., Langley, British
Columbia, Canada
General Contractor: Ledcor Industries
Ltd., Vancouver, British Columbia,
Canada
REMPEL BROS. CONCRETE LTD., 203-20353-64th Ave., PO Box 3160 , Langley, B.C. V34A 4R5,
Chilliwack: 640-792-7245, Abbotsford: 604-859-7671, Vancouver: 604-525-9344, Fax: 1-800-559-6211
Rempel Bros. Concrete Ltd. uses admixtures supplied by Grace Construction Products, a core busines of W.R. Grace & Co. of Canada Ltd.
PerformX and CrackGuard are trademarks of Rempel Brothers Concrete Ltd. Eclipse is a registered trademark of W.R. Grace & Co.-Conn.
Rempel Bros. with years of experience in warehouse construction, developed
PerformX CrackGuard, a concrete mix designed to minimize shrinkage cracking.
“There’s the whole architectural
concrete market. Polished
concrete floors are ‘in’ and
that means they must have
virtually no cracking.”
Bob Fairbank
Rempel Bros.
Before bidding on the Port Coquitlam
Costco warehouse last spring, Ledcor
Industries Limited, one of Canada’s
leading general contractors, approached
one of their preferred ready-mix
suppliers, Rempel Bros., to devise
the best mix.
Since the Mulvanny floor specification
included the use of Eclipse to minimize
concrete shrinkage, Rempel Bros.’
product quality department consulted
with local Grace Construction Products’
technical staff to develop a version of
their special proprietary mix series
PerformX, incorporating Eclipse.
Laboratory testing proved PerformX—
CrackGuard with a smaller dosage
of Eclipse®
could meet the floor speci-
fication—an economical alternative
to a regular mix with more Eclipse,
also permitted by the Mulvanny
specification.
An early indication of how well
PerformX CrackGuard with Eclipse
prevented cracking came with an initial
pour in August, 1998. A 20-by-75-
foot freezer slab had to be cast
separately from the rest of the floor.
“We put four saw cuts across the
width of the freezer slab, but the
cuts stopped about a foot short of
the edges because there was a curb,”
explained Phil Gardner, site superin-
tendent for Ledcor Industries. “We
were amazed later to see that there
was no cracking from the ends of the
saw cuts to the curbs.”
Pouring of the rest of the 145,000
square foot slab then proceeded in
five large pours. In retrospect Gardner
believes that with PerformX
CrackGuard the pour sizes for the
Port Coquitlam Costco slab could
have been increased beyond 30,000
square feet without detriment.
“I’ve not seen results like this
before. We could have expanded
the pour areas.”
Rempel Bros. foresees a variety of
concrete applications that could bene-
fit from PerformX CrackGuard with
Eclipse. Said Rempel Bros. vice presi-
dent and general manager Bob
Fairbank: “There’s the whole archi-
tectural concrete market. Polished
concrete floors are ‘in’ and that
means they must have virtually no
cracking.”
Concluded Fairbank: “We’re really
exited. We’re getting into totally dif-
ferent markets with this product.”
Costco floor slabs must not only
look great, they must perform. Floor
surfaces must not crack, break or chip
under construction and heavy loads
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