Born on the Bayou

TAS Commercial Concrete is making impressive strides helping bring Houston’s newest mixed-use project to reality.
Never wanting to be mistaken for Dallas, its flashy sibling to the north; hipster capital city Austin to the west; or Riverwalk-famous San Antonio to the south, Houston has worked hard to establish its own identity as the pre-eminent Texas city. It’s done so by offering everything from a vibrant theater scene (second only to that of New York City), a continued hot housing market, one of the largest commercial ports in the world, an impressively high influx of IT/tech workers, and serious bragging rights as the home of NASA’s Johnson Space Center. With that as a both a figurative and actual background, TAS Concrete Construction has been involved in construction of “The Allen,” one of Houston’s most anticipated new multi-use developments. Located adjacent to Buffalo Bayou Park, a hugely-popular 160-acre greenspace, the 35-story structure will offer 99 condominium units — with price tags ranging from $600,000 to $11 million — situated atop a 172-room Thompson Hotel by Hyatt Corp. Using a combination of truck-mounted pumps and a stationary unit feeding a core-mounted, separate placing boom, TAS has excelled and is already anticipating an early completion for their phase of the project.

Turnkey Solutions
TAS, which recently marked four decades of service to the concrete industry, has established a reputation for providing high-quality, on-schedule, turnkey concrete solutions for customers throughout the central, northern, and southeast parts of the state, as well as along the Texas Gulf Coast. According to Pete Black, one of the company’s area general superintendents, it is that commitment to service that made them the ideal candidate to tackle a high-profile project of this type.

“Our workforce consists of turnkey crews, including tradesmen in carpentry, rebar and concrete placement and finishing” he said. “So we have strengths in the many areas needed to tackle a project of this importance. There has been a lot of anticipation for The Allen, given its overall scope and its attractive location, adjacent to the Buffalo Bayou Park area. The developers broke ground in November 2019 and, despite the pandemic that’s altered our lives since then, it has been a hotbed of activity for us right from the outset.”

As if to underscore that last statement, Black said that the most challenging facet of the project thus far remains the earliest — this despite steady progress in almost all areas of the job (the company was pouring level 16 as of this writing),

“Coming out of the ground was definitely not a walk in the park — we started about 30 feet below subgrade and went another 10 feet below that to establish the base of the core,” he said. “The foundation consists of over 800 auger cast piles with caps that form the base upon which the structure sits. We used the 39-meter unit to pump all the piles and 113 caps which ranged in size from 30 yards to 250 yards. But all that paled in comparison to the core cap, which was a 2,000 yard, multi-lift pour. That was a pretty intense part of the job which we handled using our 43-meter pump.”

Broad at the Bottom
The overall footprint at The Allen starts out at roughly 48,000 sq. ft. to accommodate both the parking garage and retail space, then tapers back as the structure rises, settling in at 17,000 sq. ft. for the typical floors in the tower section of the project. It’s worth noting that, although only a lifestyle pavilion and the main hotel/condo tower are currently under construction, long-range plans for the development call for up to three additional structures to be built. For the parking garage area of the project, TAS once again relied heavily upon their 39- and 43-meter pumps.

“Those units were ideal for providing the horizontal reach we needed — up to 123 feet of it with the 43-meter,” said Black. “But we really benefited from the four- and five-section boom configurations, which allowed us to access many areas that already had rebar climbing and could have proved challenging — the walls for the garage are a perfect case in point. We were able to reach over and down past rebar and formwork that extended up as much as 20-feet.”

He added that the compact outrigger footprint of each pump was a huge plus for them as well. Despite the obvious congestion from multiple trades a project like this can bring, he said they were able to quickly and efficiently set up. “That tight outrigger profile meant we were able to pump from pretty much anywhere, so access from the ground was never a concern.”

Core Competencies
TAS relied heavily on those two pumps for most of the lower work on the tower as well, finally turning pumping duties over to the SPB 37 placing boom once the core had reached level 3. To maximize pour efficiencies on that section of the project, TAS opted to position the placing boom directly on the 31’ X 70’ core and utilized a Doka self-climbing forming system which allowed the placing boom to always be positioned two floors ahead of the pours needed below.

“The 37-meter placing boom provides 730° of slewing range and 120’ of horizontal reach, so we are able to easily access all areas on every floor,” said Black. “On each level, that included pouring 16 columns that typically measured 30 X 48 inches and an 8-inch thick post-tensioned deck. Because the boom also features the same four-section design as the truck pumps, obstructions such as vertical rebar or piles of material are rarely an issue.”

As anyone in construction will attest, having a contingency plan at the ready is key to maintaining progress in the face of unforeseen challenges. For TAS, that meant finding a way to deal with an inability to place their stationary pump.

“At the point we needed to begin feeding the placing boom, the area from which the stationary pump needed to work was hemmed in by scores of other subs and their material,” said Greg Kirsch, TAS’ equipment supervisor. “Until they were clear and a road could be built on that side of the project, we opted to rent a pair of truck-mounted pumps — an S 58 SX and an S 65 SXF — to feed the boom. That arrangement, while not in the original plan, worked well and was in place all the way through level 10.”

Looking Ahead
While the TAS team had envisioned handling the bulk of the placing boom work with their existing pump, an SP 4800, the combination of having an eye to the future and the prospect of raising production led to an upgrade in their choice of stationary pump.

“Moving forward, we know there are going to be more, even taller high rise projects that will present themselves and we saw this as an opportunity to set the groundwork for being competitive in bidding such projects,” said Kirsch. “With that in mind, we contacted Cole Richards, Schwing’s south central regional manager, and quickly secured an SP 9500. In addition to getting us poised for future growth, at 630 hp, the 9500 represented a dramatic boost in power over the pump we had onsite, so we knew production rates would be positively impacted as well. It was truly a win-win situation for us.”

Messing With the Schedule
In order to address the different structural demands of the project, concrete supplier Argos USA provided no fewer than 10 different mix designs. To make those mixes available in a timely manner, the company worked from multiple nearby batch plants, operating as many as a dozen trucks for the higher volume pours.

Despite the impressive scope of the project — by its end, TAS will have pumped more than 51,000 cubic yards of concrete, laden with nearly 3,700 tons of rebar — the company is finding itself outpacing projected schedules.

“Based on all the facts we had at hand in planning, we have been able to beat the published schedule,” said Black. “And while a good deal of the credit for that goes to the TAS team we’ve assembled here, there’s no denying the performance of the pumps has been key as well.”

Condominiums at The Allen will be available for occupancy by the end of 2022, while the lower 15 floors will debut as the Thompson Hotel by 2023.

 

Specs
Owners: DC Partners, Houston, Tex.
General Contractor: GT Leach Construction, Houston, Tex.
Design Architect: HOK, Houston, Tex.
Interior Design: Abel Design Group, Houston, Tex.
Structural Engineer: Structural Consultant Associates, Inc. – Houston, Tex.
Concrete Contractor: TAS Commercial Concrete, Houston, Tex.
Concrete Supplier: Argos USA, Houston, Tex.
Equipment: Schwing S 39 SX, S 43 SX, S 58 SX and S 65 SXF truck-mounted concrete pumps with placing booms; Schwing 4800/9500 trailer pumps; Schwing SPB 37 separate placing boom