Atlanta’s Midtown Mile Gets Facelift
Atlanta’s Midtown Mile Gets FaceliftPutzmeister truck-mounted boom pumps and placing system technology help makeover the heart of Atlanta
STURTEVANT, WI (April 28, 2008) – New York has Fifth Avenue and Chicago is known for its Magnificent Mile. Soon Atlanta’s Midtown Mile will hold the prestige of these coveted addresses with enhancements to its retail, commercial and residential mix. The skyline of Midtown continues to evolve and Putzmeister concrete placing equipment is helping contractors make it happen on projects like 1075 Peachtree Street (1075 Peachtree).
One of downtown Atlanta’s latest developments, 1075 Peachtree is part of an overall makeover of the city’s Midtown Mile, and is the second phase of the 12th & Midtown three city-block project. Once complete, 1075 Peachtree itself will encompass one full city block and offer up a notable 2,054,914 square feet (190,910m2) of mixed use space.
Now the largest single contributor to Atlanta’s Midtown Mile, the owner/developer team of the 12th & Midtown development includes Daniel Realty Company, LLC (Daniel Realty), Selig Enterprises, Inc. (Selig Enterprises), and Canyon-Johnson Urban Fund (CJUF). This prestigious group is helping realize Atlanta’s hopes of establishing the heart of Midtown as one of the premier shopping destinations in the United States.
A project of this magnitude calls for an impressive 120,000 cubic yards (91,750m3) of concrete. Smyrna, Georgia-based Pioneer Concrete Pumping (Pioneer) is placing 100,000 cubic yards (76,455m3) of that total amount and is easily handling the amount with their powerful Putzmeister truck-mounted concrete boom pumps and placing system equipment.
“12th & Midtown is one of our most monumental projects to date,” says Steve Baile, Vice President of Daniel Realty. “We are excited to contribute some of the region’s finest shopping and dining along with first-class residences, not to mention Class A office space and luxury hotel accommodations to the heart of Midtown.”
“The development will embody a sophisticated, yet relaxed, lifestyle,” adds Scott Selig, Vice President of Selig Enterprises.
Part of a Grander Plan
“Designed to enhance the pedestrian streetscape,” comments Baile, “12th & Midtown also maximizes the views of the Atlanta skyline and Piedmont Park.”
This part of the Midtown project comprises three phases:
Phase I: 1010 Peachtree Street – a 35-story high-rise with 443 residences and up to 50,000 square feet (4,645m2) of retail and dining space. Completion is set for September 2008.
Phase II: 1075 Peachtree Street – a 41-story 725,000 square-foot (67,355m2) hotel/condo tower, 60,000 square feet (5,574m2) of retail space and a 42-story office tower and parking deck. Completion is set for February 2010.
Phase III: 1125 Peachtree Street – 500,000 square feet (46,451m2) of office space, 40,000 square feet (3,716m2) of retail space and hotel. Completion date is yet to be determined.
A Tough Choice Made Easy
The team that will help bring Phase II of 12th & Midtown to fruition includes: Kennesaw, Georgia-based Brasfield & Gorrie as the general contractor, Rule Joy Trammell + Rubio, LLC as the architect, Stanley D. Lindsey & Associates, Ltd. (SDLA) as the structural engineer, Pioneer as the concrete pump and placing systems supplier and Thomas Concrete of Georgia, Inc. (Thomas Concrete) as the concrete ready mix supplier.
According to Brasfield & Gorrie’s Senior Superintendent, Lynn Walker, choosing Pioneer as the concrete pumping and placing subcontractor was a simple decision.
“Brasfield & Gorrie has had great experience working with Pioneer’s personnel and their equipment’s performance has been outstanding on past projects,” says Walker. “We most recently worked together with Pioneer on Regents Park in downtown Atlanta. 1075 Peachtree is actually the largest mixed use development both Brasfield & Gorrie and Pioneer have ever been a part of, which makes it even more momentous.”
With groundbreaking in late August 2007, Pioneer arrived on-site in November 2007. Many of Pioneer’s Putzmeister truck-mounted concrete boom pumps are pumping and placing concrete on this project, including their 36Z-, 43Z-, 47Z, 52Z-, 58- and 63Z-Meter models.
A Sweet Concrete Pumping Project
Since arriving on the job site, Pioneer has pumped and placed 26,000 cubic yards (19,880m3) of concrete.
The first significant concrete placement was for the 41-story hotel/condo tower mat foundation in mid-December 2007. The mat foundation was placed 35-feet below grade.
“A total of 900 cubic yards (688m3) of a 4,000-psi concrete mix was placed by our two 58-Meter boom pumps and our 63Z-Meter boom pump in four hours,” says Cory Postlewait, Account Representative for Pioneer. “The hotel/condo tower will rise 382 feet (116m) above grade once complete.”
The second major concrete placement was for the 42-story office tower and parking deck mat foundation in January 2008.
“Again, our two 58-Meter boom pumps and 63Z-Meter boom pump placed 2,400 cubic yards (1,835m3) of a 4,000-psi concrete mix, which took about seven hours,” comments Postlewait.
The office tower will stand a prominent 487 feet (148m) above grade once complete. The parking deck includes a total of 15 levels and of those, two are underground.
“The 63Z-Meter was a huge plus to have on-hand not only on both of these massive jobs but on other pours for this project as well,” notes Postlewait. “The five-section Z-Fold boom design of this unit helped us achieve exceptional boom maneuverability in the difficult-to-reach areas of this job site like the office tower slabs that needed to be placed from Juniper Street. We needed the 63Z’s vertical reach of 203' 9" (62.10m) and horizontal reach of 190' 7" (58.09m) to place the concrete exactly where it needed to be placed.”
In addition, Postlewait says the 58-Meter’s vertical reach of 188' 1" (57.33m) and horizontal reach of 174' 3" (53.11m) have also helped to place the concrete efficiently for both of the mat pours.
“Both the 63Z-Meter and the 58-Meter unit can pump up to 260 cubic yards per hour (200m3/hr) and have handled the different strengths of concrete mixes with ease, along with the rest of our other boom pumps,” adds Postlewait.
Currently, Pioneer averages two truck-mounted concrete boom pumps on-site each day, Monday through Saturday.
Jason McEntire, Commercial Sales Manager for Thomas Concrete, says “Pioneer is consistently handling two to three slabs per week. Slabs are placed in the mornings and verticals are placed at varying times throughout the day.”
Steady as She Goes
According to Postlewait, about 150 cubic yards (115m3) of concrete per pour, or 300 cubic yards (230m3) per floor are pumped and placed in the hotel/condo tower by Pioneer’s truck-mounted concrete boom pumps. In April, Pioneer used their 63Z-Meter to pump and place 180 cubic yards for part of the hotel/condo’s ninth floor. In combination with the 63Z, Pioneer also used their new Putzmeister Steady End Hose on this pour.
“We have four Steady End Hoses at Pioneer and we share them among the pumps,” notes Postlewait. “Our number one priority for our crew on job sites is safety. When using the Steady End Hose, we know there is a significantly reduced risk of the unpredictable and sometimes dangerous whipping you can have with an end hose. Using the Steady End Hose is just one step we can take to make sure everyone leaves the site safe and sound at the end of the day.”
"We’ve found the Steady End Hose is easier to handle than the traditional end hose,” adds Tom Inglese, Area Manager for Pioneer. “The Steady End Hose is made of a specially-designed reinforced fabric which makes positioning the concrete easier for the hose man. The Steady End Hose is more controllable in the event of an unexpected blockage because it dampens lateral deflections and excess vibrations.
“Pioneer is planning on purchasing more Steady End Hoses from Putzmeister,” adds Inglese. “If we have more Steady End Hoses available to use on our pumps, that means we’re helping to reduce the risk of the dangerous hose whipping from occurring on even more job sites.”
For the office tower, about 500 cubic yards (380m3) of concrete per pour, or 1,000 cubic yards (765m3) per floor is pumped and placed. Pioneer has pumped and placed concrete up through the eighth floor.
For the parking deck, located beneath the office and hotel/condo towers, about 400 - 600 cubic yards (305 – 460m3) of concrete are pumped and placed per pour. Five different pours occur per each parking deck floor. Currently, Pioneer has pumped and placed concrete up through the fourth level of the parking deck.
A Closer Look at the Concrete Mixes
According to McEntire, the concrete mixes being used for 1075 Peachtree range from 3,000 to 12,000 psi.
“For the lower level columns and walls, the 10,000- and 12,000-psi concrete mixes are being used,” comments McEntire. “The high strength concrete being utilized in the lower columns and walls will serve to support the massive structure that will rise into the Midtown sky.
“To help achieve the high strengths required we are utilizing a range of admixtures and associated products to produce a mix that is guaranteed to meet the project requirements while also insuring that Brasfield & Gorrie’s construction sequence remains on schedule,” adds McEntire.
McEntire also adds that there is approximately 4,000 cubic yards (3,060m3) total of the 12,000-psi and 10,000 cubic yards (7,645m3) total of the 10,000-psi concrete mix being used for 1075 Peachtree.
“The elevated post-tensioned floor slabs for both the office and hotel towers are specified to reach a 28-day design strength of 5,000 psi with a target strength of 3,000 psi in 24 hours in order to stress tendons,” says McEntire. “This high early mix is produced with type III cement and chemical admixtures. After the target strength of 3,000 psi is confirmed then Brasfield & Gorrie can stress tendons, strip forms, install vertical columns and walls, and proceed to forming the next elevated floor.”
According to McEntire, the slab-on-grade for both the office tower and parking deck, and the hotel/condo include specialty fibers as specified by the design team.
“The office tower and parking deck slab-on-grades included a three pound per yard dosage rate of 1.5-inch fibrillated polypropolyne fibers as specified by SDLA,” notes McEntire. “Newer generation fibers allow for better management of plastic shrinkage control while offering additional concrete reinforcement when utilized in higher dosage rates. 1075 Peachtree is one of the first projects in Atlanta to include this application.
“The slab-on-grade for the hotel/condo side of the project included a five-pound dosage rate of Forta Ferro Fiber manufactured by the Forta Corporation out of Pennsylvania. Ferro Fibers design qualities meet the definition of a true structural fiber,” adds McEntire. “This product offers a greater amount of structural reinforcement than typical fibers while also assisting with plastic shrinkage control and minimizing, if not eliminating altogether, unsightly surface cracking. Any specialty fiber used at a high dosage rate requires careful coordination between the project construction team, the concrete supplier, the pump company, and the fiber manufacturer in order to ensure a placement’s success. Pioneer did a great job of being prepared to provide the right equipment and displayed their continued high degree of professionalism in this endeavor. Again, this application was specified by SDLA and 1075 Peachtree is one of the first projects in Atlanta to have it incorporated into the design.”
The 3,000-psi concrete mix, according to McEntire, is used only minimally on the project for miscellaneous concrete needs.
The Right ‘Place’ at the Right Time
Pioneer began the 1075 Peachtree project with their truck-mounted concrete boom pumps, but they are now bringing in their innovative Putzmeister pin tower and placing boom technologies as well. According to Postlewait, the truck-mounted boom pumps will continue to be on-site throughout the project helping to pump and place concrete, along with the placing systems.
“We will phase in two 34/38Z-Meter Series II Detach placing booms and one 36/40Z-Meter Series II Detach placing boom mounted on freestanding pin towers over the next few months,” says Postlewait. “We just installed the 50-foot freestanding pin tower and a 36/40Z-Meter placing boom for the office tower. In May, we’ll install the hotel/condo tower’s pin tower and placing boom and then in June, we’ll install the parking deck’s pin tower and placing boom.”
The hotel/condo tower will temporarily use the BSA 2110 trailer pump as its pumping station until access is available by re-shore removal, according to Walker. Once access is available, the hotel/condo tower will join the office tower and parking deck in using the BSA 14000 trailer pump for a pumping station. All three will then share the pump which will be positioned at a central location.
As the office tower, hotel/condo tower and parking deck reach higher, a crane will be used to add more sections to the three pin towers.
“With Atlanta’s high-rise boom taking hold in the past few years, we’ve had a chance to really observe and show what our placing system technology can do,” comments Postlewait. “1075 Peachtree is yet another opportunity to highlight the benefits of this solution for high-rise mixed use developments in regards to the concrete placement technique and impact on a project’s timeline.
Some of Pioneer’s recent high-rise projects where they have or are using their placing system technology in the Atlanta area include: 12th Centennial (downtown Atlanta), Rubbermaid® corporate offices (Sandy Plains, Georgia), Peachtree Point II (downtown Atlanta), and The Offices at 3630 Peachtree (downtown Atlanta).
“We are all seeing how high-rise developments continue to dominate the construction scene not only in Atlanta, but across the country,” adds Postlewait. “It’s an advantage for us, as the diversification of our services and expertise in both truck-mounted boom pumps and concrete placing systems is keeping our company in higher demand.”