Project Profile
Environmentally Preferable Concrete
One World Trade Center
Project:
One World Trade Center
Location:
New York City, New York
Owner/s:
Port Authority of New York/New Jersey
Concrete Contractor:
Collavino Construction Company
Concrete Producer:
Eastern Concrete Materials, a U.S.
Concrete Company
Products Used:
MasterSure® Z 60
workability-retaining admixture
MasterGlenium® 7500
high-range water-reducing admixture
MasterSet® DELVO
hydration-controlling admixture
MasterLife® SF 100 silica fumeMarket Sector:
Ready-mixed concrete

Soaring to a height of 1,776 feet (540-meters), the 2.6-million-square-foot(242,000-square-meter) skyscraper known as One World Trade Center in thelower Manhattan district of New York City is a marvel of design and engineering.
Construction of the building, previously called the Freedom Tower, began in April
2006 and at the time was the tallest building in the United States.

The Challenge

Sustainable design was a central theme to One World Trade
Center’s development, with the Port Authority of New York/New Jersey imposing a strict requirement for the replacement ofportland cement with recycled materials. In addition, extremely
high-performance concrete was necessary to meet thecompressive strength requirements of the steel and concrete
structural columns, which ranged from 14,000 psi (97 MPa)
to 12,000 psi (83 MPa) for the lower 40 floors and 10,000 psi(69 MPa) to 8,600 psi (59 MPa) for the upper floors.

Chart 1. Environmental impact of sustainable concrete
for One World Trade Center, as compared to a standard
reference mixture.

Environmental
Impact Category

EnvironmentalBenefits

Energy usage

25,400,000 kWh(91,440,000 MJ)

Greenhouse gas emissions

34,800,000 lb CO2eq 		(15,785,000 kg)

The 12,000 psi (83 MPa) concrete phase of the project was themost challenging, with the engineers, owners and contractors all
having their own requirements and specifications.

Water emissions

5,247,000 gal (19,862,000 L)

Engineering Requirements

Based on 145,000 yd (110,900 m ) of concrete developed for six compressive strengths.

• Compressive strength: 12,000 psi (83 MPa) @ 56 days
• Over-design for safety: 1,900 psi (13 MPa)
• Modulus of elasticity: 7.0 million psi (48 GPa)
• Heat of hydration: Not to exceed 160 °F (70 °C)• Non-air-entrained
Port Authority of New York/New Jersey Requirements:• Quantity of portland cement in the mixture:Less than 400 lb/yd3 (240 kg/m3)
Contractor Requirements:• Slump flow: 24 - 28 inches (610 - 710 mm)• Ability to pump to at least 40 floors• No loss in concrete workability during transit and placement• Aesthetically pleasing

Master Builders Solutions

To achieve these concrete properties which, combined, would
be a groundbreaking feat, concrete producer Eastern Concrete
Materials, Elmwood Park, NJ partnered with admixture supplier
Master Builders Solutions, Beachwood, OH.

The comprehensive portfolio under the Master Builders
Solutions brand encompasses concrete admixtures, cementadditives, chemical solutions for underground construction,
fiber reinforcement solutions, waterproofing solutions, sealants,
concrete repair and protection solutions, performance grouts,
and performance flooring solutions.

Solid waste

1,720,000 lb (780,178 kg)
3The Results

Through Master Builders Solutions‘ Green Sense Concrete
mixture optimization service, Eastern Concrete Materials wasable to proportion an EF Technology® concrete mixture with 71%
cement replacement. The mixture replaced portland cement withthe recycled materials, non-cementitious fillers and specialized
admixtures to exceed all the performance targets specified
by the One World Trade Center project stakeholders. This EF
Technology mixture was used for the 38,000 yd3 (29,000 m3) ofconcrete needed for the columns through the first 40 floors.

3The Master Builders Solutions brand brings expertise to createchemical solutions for new construction, maintenance, repair
and renovation of structures. Master Builders Solutions is built
on the experience gained from more than a century in theconstruction industry.
The know-how and experience of a global community ofconstruction experts form the core of Master Builders Solutions.
We combine the right elements from our portfolio to solve yourspecific construction challenges. We collaborate across areasof expertise and regions and draw on the experience gained
from countless construction projects worldwide. We leverage
global technologies, as well as our in-depth knowledge of local
building needs, to develop innovations that help make you more
successful and drive sustainable construction.

To quantify the environmental impact of sustainable concrete forthe structure, an Eco-Efficiency Analysis was conducted, using
a methodology validated by NSF International, to compare thespecialized EF Technology mixture to a reference mixture. The
results of this cradle-to-gate analysis are included in Chart 1.
Some practical equivalents for these savings are:
• Water savings equal to 1,177,329 half-liter bottles of water• Reduced carbon footprint equal to 1,835,494 gallons of gasoline• Fossil fuel savings equal to 29,872 barrels of oil

Master Builders Solutions
Admixtures US, LLC
23700 Chagrin Boulevard
Cleveland, Ohio 44122-5544
800-628-9990

Master Builders Solutions
Canada, Inc.
1800 Clark Boulevard
Brampton, Ontario L6T 4M7
800-387-5862

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