Building For Sustainability

By John Tiernan

With recent worldwide crises in mind, it seems a good time to focus on how to construct for chaos. Whether earthquakes, tidal waves, forest fires, or floods, what are the best preventive construction methods?

Concrete and reinforced concrete appear to be materials of choice for many reasons that might be wrapped into one word: Sustainability.

Some Considerations

David Bilow, director of engineered structures for Portland Cement Association offers some thoughts on building for sustainability, some of which are incorporated below.

• Might concrete better replace wood-frame construction on the Gulf Coast and in other hurricane-, tsunami-, or flood-prone areas? Yes, it would seem that concrete structures will stand the battering of high winds and water pressure better than stick-built houses. David Bilow notes that FEMA is recommending concrete in floodplains in lieu of wood and drywall, which fall apart and rot when wet. Of course, that presumes that the need to build in floodplains has been addressed first. Regardless, Bilow says that concrete structures can also be cleaned more easily after water infiltration than wood. And because mold doesn’t penetrate concrete as it does wood, it can simply be washed off the surface, he adds.

• How does concrete compare with steel as a sustainable material? Bilow says that whereas a steel bridge must be painted every seven years on average, a concrete bridge needs virtually no maintenance. As for structures, the greater mass of concrete uses energy more efficiently—with a 12% advantage for concrete over steel, and some 25% advantage for insulated concrete.

• What’s the comparison when it comes to extraction, processing, and transport? Bilow says that the primary costs for concrete are less than for steel because steel is typically shipped long distances, whereas concrete is made locally.

• And recycling? True, most steel is also recycled—far more than lumber—but typically, used concrete is crushed for aggregate used in roadbeds, and often is recycled to manufacture new concrete.

Here, then, are some of the most important concrete projects of this past year and next.

10 Infrastructure Projects to Watch

	Everglades Restoration Florida In test stage This is a monumental project costing $1.5 billion, to manage the water flow in virtually the whole southern half of Florida. It involves massive concrete dams, dykes, canals, reservoirs and roads. Test cells have been constructed, but most remains to be started.
	U.S. Navy Modular Floating Pier San Diego, CA Now being installed This is a 325-ft-long double-decked berthing pier designed for 100-year life, and to support multiple 140-ton cranes and service a variety of vessels. It will accommodate tide and wave action on telescoping columns. Assembled in Washington state and barged south.
	San Francisco-Oakland Bay Bridge California 65% complete Precast segmental bridges are rare in California. This uses huge segments—500 to 800 tons each.
	Benicia-Martinez Bridge California Under construction This employs lightweight concrete, which reduces foundation cost.
	High Five Intersection Dallas, TX Completion December, 2005 This is the largest bid-build project in Texas history at $1 billion. It includes five levels of concrete roads and is one year ahead of schedule.
	Loch Raven Dam Baltimore County, MD Nearing completion Built in 1912 and heightened over the years, it is being reinforced to withstand storms with pins through to bedrock, reinforced concrete on the face and roller-compacted concrete on the toe and face.
	Galena Creek Bridge Reno, NV Underway At 1,719-ft-long—and 300 ft above the water—this will be the longest concrete cathedral-arch bridge in the U.S.
	Ten Mile Creek Water Reservoir Fort Pierce, FL Completion in December, 2005 This is a critical restoration project involving construction of an above-ground reservoir and pump station, a gated water-level control, a gated drain facility and control structures.
	St. George Island Replacement Bridge Franklin County, FL Completed 2004 A 4.1-mile-long bridge crossing environmentally sensitive water. When begun, it was the single largest design-build project ever undertaken by Florida’s Dept. of Transportation.
	Replacement Bridges For I-10 Over Escambia Bay Pensacola, FL The first one is to be in service December, 2006. Hurricane surges in 2004 damaged the existing bridge. The twin replacements are a $242-million design-build job with a $10 million incentive. The project will employ 20 waterborne cranes.

10 Buildings to Watch

	FDA CDER Office Building White Oak, MD Under construction This is part of a consolidation of headquarters into a single campus to improve operating efficiencies and offices that are flexible enough to adapt to future changes. The completed campus will consist of over 2 million sq ft of space in 12 buildings constructed over 8 years, with a projected construction cost of $900 million. The first phase is for the Center for Drug Evaluation and Research (CDER), and consists of a six-story building, plus basement, of more than 400,000 sq ft. The facility houses office, conference and storage functions. The basement level connects to an underground utility and materials-distribution tunnel system that links all campus facilities to a central utility plant and central loading areas. The project also includes two enclosed pedestrian bridges to adjacent laboratory and office facilities.
Ivana Condos Las Vegas, NV In planning stage	This will be the tallest residential building west of the Mississippi River, with 80 stories rising 923-ft.
	American University Arts Center Washington, D.C. Completed in July, 2005 The 130,000 sq ft, three-story Katzen Arts Center, on the campus of American University, combines under one roof, facilities for the visual arts, music, theater, dance, art history, gallery techniques and arts management. It includes a 30,000 sq ft, three-story art museum and sculpture garden, a sky-lit rotunda, three performance venues, an electronics studio, nearly 20 practice rooms, a 215-seat concert hall, new rehearsal and recital halls, classrooms and an underground parking garage with 550 spaces. The concrete building structure has a boldly sculptural form. The contract amount is $48 million.
	The Nicollet Minneapolis, MN Under construction A 50-floor post-tensioned concrete structure, it will be the tallest residential building in town.
	140 West 42nd Street New York, NY In planning stage This will be the first post-tensioned concrete office tower in Manhattan since the early 1970s. The 24-story structure will have floor-to-floor height reduced by more than 3 ft compared to the originally planned steel structure. The flat-plate floors will have clear spans to 40 ft, gaining the space that would have been lost from steel columns.
NOAA Satellite Operations Facility Suitland, MD Under construction A Design Excellence award went to this project. The 19,350 sq m comprise 14,000 sq m of modern office space and 5,350 sq m dedicated to the satellite operations group. That includes a Satellite Operations Control Center (SOCC), a Launch Control Center, and CEMSCS, a computer facility that processes data obtained from the SOCC. The first building is a single-story structure over a parking basement, with a partial mezzanine and a shallow dome-shaped roof covered with grass. The second building sits atop the first and has two additional stories with partial mezzanines. It includes spaces for launch-control facilities, visitor facilities, a conference center and an entry lobby. On the roof of the second building are mounted an array of various sized antennae for tracking satellites. The contract amount is $53 million.
Trump International Hotel & Tower Chicago, IL Under construction At 92 floors, it will be one of the tallest buildings in town.
Heritage at Millennium Park Chicago, IL Under construction	This will be the tallest residential building in the Loop, with 57 floors.
	340 On The Park Chicago, IL Under construction This 64-floor residence will have large bay spacing at 22 x 35 ft, and will use flying forms when the typical floors begin.
	2310 Crossroads Madison, WI Under construction A departure for the Midwest, this five-story office building is set into a hillside using tilt-up concrete erection construction. It illustrates how the method can be used to save money while allowing freedom for architectural details.

Project Spotlight

Precast Box Storm Water Vault Meets
Environmental and Structural Design Challenges

Storm water ponds are often used to provide treatment of storm water before it is released into water bodies. In densely populated developments, system requirements are large and ponds are not always feasible or desirable. At the Westshore Yacht Club in South Tampa, the permits required that the first inch of storm water runoff be treated prior to discharge into Old Tampa Bay.

Precast concrete retention and/or detention systems are a viable alternative to storm water ponds. Here, the engineer recommended a precast concrete system over cast-in-place system largely due to final grade limitations, water table concerns and overall reduced construction costs. Other benefits include immediate backfilling for faster installation and a reduction in cost for traffic control and project management.

Frequently, precast concrete box systems are compared to cheaper vault systems constructed of plastic or metal pipes and chambers. Such a comparison almost always favors precast concrete—because of structural integrity with minimal or no cover, a greater service life and reduced installation footprints. Precast concrete box structures, as demonstrated on this project, provide a solution that is both environmentally responsible and structurally sound.

Precast concrete box sections and pipe used in retention/detention applications are increasingly becoming recognized as alternatives to storm water management ponds. The precast concrete vault system in place at The Westshore Yacht Club is designed to function for decades under a planned maintenance program. Engineers weighed the alternatives and specified a material and product that best met physical and regulatory challenges. Residents of the area are left with a healthy and safe environment.

With contributions by Jeffery A. Hite, Rinker Materials - Hydro Conduit Division, Plant City, FL
Mark Pirrello, P.E., Moffatt & Nichol, Tampa, FL.

Prairie Material Builds a Strong Foundation for Trump Tower in Chicago

The concrete foundation of the Trump International Hotel and Tower super-structure in Chicago was poured on Friday, Sept. 30. The 5,000-cu-yd monolithic continuous pour using Rheodynamic® Self-Consolidating Concrete (SCC) began late Friday morning and lasted approximately 24 hours. The foundation, referred to as a mat, is 198 ft long x 60 ft wide and 10 ft deep. To date, this is the largest single SCC pour in North America.

Concrete producer Prairie Material Sales Inc., along with its chemical admixture supplier Degussa Admixtures Inc., collaboratively designed a concrete mix that would adhere to the strict specifications. The maximum temperature allowed during the placement of the concrete was 80°F and the maximum temperature of the concrete in place was 170ÞF degrees. The specification also called for the use of self-consolidating Concrete with strength of 10,000 psi produced on a continual basis. The combination of requirements made for a challenging mix design that has never been done before. Over 30 ready-mix trucks from Prairie’s plant made 600 trips to the site. The trucks unloaded the concrete onto 3 large conveyors that placed the concrete into the mat.

“This pour, as difficult as it was, shows how Prairie does business. This was a true collaborative effort between our company and the people at McHugh Construction,” says Paul Blatner, vice president of operations for Prairie Material Sales Inc.

Joseph Daczko, product manager from Degussa Admixtures Inc. adds, “We were proud to be a part of this project and work with the talented people of Prairie Material.”

Expected to be completed in 2009, Trump International Hotel and Tower will be 92 stories tall, consist of over 2.6 million gross sq ft of building area and more than 180,000 yds of concrete. The Tower will be constructed of concrete instead of steel so it will fit in the limited space available.

3 Million Gallons Under the
Playing Fields

They put it in an odd place. As it was hard to find a suitable site for a big storage tank on the very densely built USC campus in downtown Los Angeles, authorities decided to bury the tank under the infield running track. The tank in question is a recently completed 3-million-gallon stratified-chilled-water thermal-energy-storage (TES) tank. DYK Inc., El Cajon, CA—the tank constructor—recognized the importance of minimizing the impact on the track facility and the surrounding campus activities while operating under a very tight construction schedule.

Since the tank was to be situated in an area of high potential seismic activity, DYK designed it to exceed seismic Zone 4, and strandwrapped it with seven-wire galvanized strand for circumferential prestressing.

In addition to being cost effective, TES tanks reduce cooling energy use, improve reliability and efficiency, and minimize chiller capital and maintenance costs.

3,100 Tons of Reinforcing Steel Bars

This 48-story cast-in-place concrete high-rise residence on Chicago’s lake shore used 2,750 tons of uncoated steel reinforcing bars internally. But outside, the two parking garages, and elevated roadway, that were exposed to weather employed another 350 tons of epoxy-coated steel reinforcing bars to protect against corrosion from salts and reduce maintenance. The epoxy coater/fabricator was Toltec Industries. The contractor was Walsh Construction.

Tools of the Trade

Deck Supports Multi-story Buildings

A developing trend in concrete construction is the design and engineering of forming equipment for specific structures. An example of this development is the DeckFast system from Symons.
The DeckFast system is specifically designed for concrete deck support in multi-story buildings. Just two basic components, a panel and post shore, provide the labor savings and forming productivity necessary for competitive bidding.

The large 180 cm x 180 cm DeckFast aluminum panel (nominal 6 ft x 6 ft) reduces handling and set-up time. The high-capacity galvanized post shore with drop-pin design provides productivity. It is not unusual to average 1,000 sq ft per person per day for most flat-slab conditions. Compare this to an optimistic 450 sq ft per person per day with conventional shoring systems and the productivity advantage is obvious.

The DeckFast system will support heights up to 18 ft, 11 in. and slab depths of up to 22 in. This allows form heights in excess of 18 ft without the need to stack and brace multiple shore frames and slab depths up to 22 in. without the need to engineer and position frames, stringers and joists.

The DeckFast panel has factory-installed and frame-protected plywood that provides an excellent concrete finish. Savings on plywood remain in the pocket of the contractor.
When 100% reshoring is required, jobs benefit from the 180 cm x 180 cm panel spacing. The same DeckFast post shore that supports the panel becomes the reshore on previous levels.

A Smooth Finish

When an architectural finish on concrete is desired, fiberglass forms have a good application, as shown here on this library project in Minneapolis. With specs that required minimal seams and bug holes, the contractor selected fiberglass custom column forms from MFG Construction Products Company to pour the 400 columns diminishing from the first floor’s 19-ft height by one ft less on each upper floor.

5 Simple Solution to Brittle Punching Shear

A product that can anchor to the top tier reduces the possibility of the induced shear cracks bypassing the shear reinforcement, thus preventing brittle punching shear failure.

Because the LENTON® Steel Fortress, from ERICO, Inc., can encapsulate the upper layer without unduly affecting cover, it overcomes the inability to anchor over the uppermost tensile reinforcement layer that some other systems encounter.

Dewatering for Footings In a River

A proposed cable car/gondola will carry visitors across the Delaware River to a historic area, crossing between NJ and PA.

To prepare for building a foundation and support column it was necessary to dewater a 400-sq-ft area 19 ft deep inside the sheeting walls that were holding back the river.

A crane on a barge in the river delivered three 12-in. Godwin DPC300 and one 8-in. Godwin CD225M Dri-Prime pumps from the shore to the construction site for dewatering.

The pumps worked continuously for one month inside the cofferdam—the 12-in. unit operating at 3,000 GPM, and the 8-in. unit at 1,500 GPM. Such intense dewatering was necessary to keep the area dry for the concrete to cure properly.

A note about Dri-Prime® Pumping Applications for the Concrete Industry: Godwin automatic self-priming Dri-Prime pumps are used for general dewatering in building, foundation and bridge construction, coffer cell dewatering, pile jetting, barge ballasting, and concrete cooling applications.

A Forming Face That’s Also is a Formliner For Smooth-Skinned Concrete

Special architectural requirements for highly representative buildings or for special civil engineering works often demand a high-quality concrete finish without any joints or marks from the formwork panels. Until now, expensive large, plywood, sheets were used. But they often had to be replaced after one or few reuses due to their loss of surface quality depicted in the concrete surface.

Today, the alkus-sheet offers a real economical option. MEVA developed a new method which allows welding several alkus-sheets together. The weld seams are nothing more than capillary joints, that are barely recognizable in the concrete surface. The advantage of the large alkus-sheets is that they can be reused as frequently as required without leading to a drop in the quality of the concrete surface. When large sheets no longer are required, they can be cut to size and built into formwork panel frames or used as facing on slab tables or attached to a girder formwork where they still can produce an outstanding concrete finish for many more years. Also, pre-bent alkus-sheets are being used more often to produce standard parts that have exceptional geometry—such as vaultings, gradients or radii—and still require high requirements made to the concrete finish.