Concrete Towers Over Chicago
For the first time in its history, Chicago has three supertall skyscrapers under construction, and all utilize high-strength concrete and a combination of a concrete core attached to perimeter super columns.

Trump International Hotel & Tower, which will soar to a total height of 1,362 feet, currently stands at more than 500 feet.  The Waterview Tower has just emerged from the ground on the corner of Wacker Drive and Clark Street and will reach 1,047 feet when completed.  Finally, the Spire on Lake Shore Drive will be the nation’s tallest building at 2,000 feet.  The Spire currently is only a hole in the ground, but contractors will soon pound steel and concrete caissons 120 feet into the bedrock below.

Each tower will use a core and outrigger system that allows a tower to place more usable square footage at the exterior of the building allowing more natural light and larger surrounding views. Concrete “arms” will extend away from the building’s core and attach to high-strength structural columns at or near the perimeter.  The enormous weight of the concrete core and super columns reduces the wind-caused oscillation.

Completion dates for the superstructures are:  Trump in 2009, Waterview in late 2009 or early 2010, the Spire in late 2010.
Photo courtesy of Skidmore, Owings, & Merrill, LLP

Better Roads Covers RCC                  
The increased use of roller-compacted concrete (RCC) was the focus of the cover story of the August issue of Better Roads magazine.  Highlighting the fact that in several instances RCC is found to be more economical than asphalt, the article profiled the May RCC seminar in Nashville.  David Luhr, Ph.D., P.E., past program manager at PCA discussed RCC’s additional advantages of higher strength, longer life, and lower maintenance costs. The article went on to discuss how RCC is prepared and placed and the equipment needed for a project.
Visit Better Roads to view the article
The reprints of the article are available at the PCA Bookstore

Cement Silos on Fast Track
Six high-rises will soon change the skyline in West Sacramento, Calif., but they are not condos.

CEMEX is scheduled to build six cement silos, the tallest topping out at 222 feet along the Port of Sacramento's shipping channel.  When finished they will loom larger than the nearby state Capitol. In addition to their stature, the silos are gaining attention for the expected speed of construction.  Construction is scheduled to start September 10 and be finished in two weeks.

"It will be continuous pour (of concrete), 24 hours a day," says Port Manager Mike Luken.

The six silos will go up simultaneously. Circular forms -- 60 feet in diameter -- will be filled with concrete, then slipped upward as the wall sets. They'll rise about 10 feet a day, until reaching their peak of 162 feet. The central silo, which has a loading elevator in its core, will climb an additional 60 feet.

Once the six silos are completed in October, the CEMEX facility will be capable of handling 1.25 million tons of cement, generating about $1.25 million in annual revenue for the port. CEMEX plans to build a "state-of-the-art" cement terminal, with eventual plans for aggregate storage and concrete mixing.

The long-planned project relocates and expands the terminals’ current location, which is destined for parks, residences, and offices.

Cement Plant to Go ‘Off the Grid’ This Fall
California Portland Cement Company held a groundbreaking ceremony and recognition luncheon on August 30 at its Mojave, Calif., plant to celebrate the construction of the eight 3-megawatt wind turbines. 

When completed in October, the turbines will supply nearly all of the plant’s electric energy. The 24-megawatt wind facility is expected to generate electrical energy equivalent to that consumed by 652 homes.

“The plant will literally be running with the wind,” said Plant Manager Bruce Shafer.  “Up to this point the Mojave plant’s electric bill was in the millions. Now in partnership with Oak Creek Energy Systems our meter will soon be running in reverse.”

Concrete Condos in Montana by Way of Portland: Concrete condominiums were the focus of a visit to the architecture students and  faculty members  from Montana State School of Architecture to Portland, Ore.,  to learn more about multi-story urban structures.  The Northwest Cement Producers Group organized the tour to visit ongoing projects in the Pearl District, as well as at the South Waterfront—notably the 16-story, 175-foot-tall, concrete-framed Encore condominium.  PCA has scheduled seminars in the area to support the heightened interest of the design community in the efficient design of the large-scale structures.
Contact Attila Beres

St. Olaf Science Complex Goes Platinum: The St. Olaf Science Complex, Northfield, Minn., will have enough LEED credits to qualify as the first platinum level university science building in the country, says project architect Holabird+Root. (The project was previously featured  in the Executive Report .) At the recent conference of  the Society for College and University Planning, the building generated interest by schools around the country.
Contact Amy Trygestad

WTC Design Consortium Invites PCA: PCA's Mike Mota was invited by the Downtown Design Partnership (DDP), a consortium of four major design firms to give a technical presentation on high strength concrete for buildings. The DDP is the structural firm for the new PATH Station at the World Trade Center site designed by Santiago Calatrava. Forty-five decision makers attended the event which also included architects from the Port Authority of NY and NJ, owner of the project. 
Contact Mike Mota

Results from Last Week:
Readers Overwhelmingly Favor LEED Credit for Durability
The Canadian version of the LEED rating system for green buildings offers a credit for durability. Should the U.S. version follow suit with a credit for a durable building envelope?

> Yes: 95%
> No: 5%

Take the current PCA Poll