COVER FEATURE

Thin-Brick Panels Add Distinctive Accent to All-Precast Concrete Office Building

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Tom Nelson, FAIA Project Principal

BNIM/CDFM2

Kansas City, Missouri

G. Kelley Gipple, P.E. Senior Vice President Structural Engineering Associates Kansas City, Missouri

H. Cam Blazer Ill, P.E. Project Manager

CSR Qu inn Marshall, Missouri

Precast and prestressed concrete, together with architectura l precast concrete, were used innovatively to build the new $13 million, five­story 333 West Eleventh Street office building in Kansas City, Missouri. Adjacent and beneath the building are two below-grade and three above­grade levels for parking vehicles. The precast/ prestressed structural system provided an economical way for the designers to match the 60 ft (18.3 m) parking bays below to the overhead office spaces. The exterior of the building features curves, overhangs and roof details that are created imaginatively from a combination of wide glass expanses, curta in wall and thin-brick-set architectural precast panels. This article presents the design and construction challenges, architectural and structural features, design considerations as well as the production and erection highlights of the project.

The new 333 West Eleventh Street office building in Kansas City , Missouri, is an all-precast concrete five-story facility with several distinctive features .

Adjacent and underneath the building is a parking structure with two below-grade and three above-grade levels. The structural frame of the building comprises precast/pre­stressed concrete components while the exterior has wide glass expanses and a curtain wall accented by thin-brick-set architectural precast panels (see Fig. 1). The combined ef­fect produced a building that met the functional, strength, durability , aesthetic and cost requirements of the owner.

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Key among the needs of the owner, a rapidly expanding data-processing company, was the creation of about 100,000 sq ft (9290 m2) of office space plus parking for at least 400 cars. Creating these spaces on the re­stricted , L-shaped site proved quite challenging. The design was compli­cated further by the desire for a facade treatment that complemented the sur­rounding buildings , many of which were brick-faced (see Fig. 2). In addi­tion, due to tenant and financing needs, the project faced a tight con­struction schedule.

This article presents the design and construction challenges, describes the architectural and structural features of the building, and discusses the pro­duction and erection highlights of the project.

The building program was designed to supply approximately 19,500 sq ft ( 1810 m2) of office space on each of five floors (see Fig. 3). Parking facili-

Fig. 1. The 333 W est 11th Street office building in Kansas City, Missouri, combines a precast structure, thin-brick-set precast architectural panels, precast accents and wide window expanses.

Fig. 2. Thin-brick architectural panels help the structure blend with nearby buildings.

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Fig. 3. Office levels required only four interior precast structural columns, providing flex ib ility in layouts.

ties were laid out to_offer SO_D_parking spaces on two ramped side-by-side parking decks that flank the building, including two below-grade and three above-grade levels with 60ft (18.3 m) long bays (see Fig. 4) .

The desire for clear-span bays in the parking structure led to the all­precast structural design for the of­fice building as well. The challenge typically rests with matching the of­fice column bays [usually 30 to 45 ft (9.1 to 13 .7 m)] with the desired garage column bays of 60ft (18.3 m). In thi s case, the design team de-

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cided to use 60 ft (18.3 m) long double tees in the office building to avoid the parking penalty that would have resulted from adding additional columns to the parking levels below.

With that design element in mind, it soon became apparent that an all-pre­cast concrete solution could be used for both the office building and park­ing structure. This concept was rein­forced by the additional economies that would result from the speed with which the precast components could be produced and erected.

VALUE ENGINEERING USED

In achieving thi s final design , the design/construction team brought the precast producer into the planning stages early to allow the company's designers to provide value engineering for every design element. The pre­caster, CSR Quinn, had built several buildings for the client and was famil­iar with the company's needs and ap­proaches. Allowing the precaster to re­view drawings as they were finished in the design formulation stage al-

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• • • •

1.1£ Of lli.D6. AT LfVEL B2

• PARKING LEVEL 83

l N

Fig. 4. Shear walls in the underground parking levels were designed to allow for 60ft (18.3 m) bays, opening the space for better parking layouts.

lowed his staff to devise the best effi­ciencies and determjne how changes could lower the overall cost without affecting other aspects of the design.

This also perrilltted the precaster to get a jump start on producing the pre­cas t co mponents and creating the piece drawings that would be needed. The precaster essentially entered into a negotiated contract with the owner that then was assigned to the general contractor as work passed out of the design phase. Drawings were shipped to the precaster at regular intervals to update their designers on where the

September-October 1997

design stood. Due to the complexjty of the facade and its details, 467 produc­tion drawings were needed to properly document the 722 precast components used to construct the office building (see Table 1). Another 440 precas t components were used in the parking structure (see Table 2).

A key element of the project came in planning the 60 ft (18.3 m) office bays. The structural engineer worked with the precaster to determine if the structure could handle 100 lb (45 kg) live loads needed to span the spaces being planned. The precaster in turn

deterrillned that the loads could be met and helped devise a design for 20,000 sq ft (1858 m2

) footprints that could be ac hieved with only four inte rior columns. This approach greatly en­hanced space plannjng and added flex­ibility in changing interior spaces to meet future needs.

PARKING USES AVAILABLE SPACE

The parking facility was designed as a combination below- and above­grade structure to take full advantage

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of the tight site restrictions (see Fig. 5). Usually, the goal would be to make the parking independent of the build­ing , but it was required that every square foot of available space be used, so below-grade space running beneath the office structure was needed. The above-grade parking facade features a combination of thin-brick-faced span­drels and metal spandrels to provide a complementary appearance to the ad­jacent office (see Figs. 6 and 7).

Table 1. Precast concrete components for office building section.

Type of component Number of components

The key to this type of combined development comes in ensuring the drainage works effectively . With a minimum overdig available, the goal was to drill through rock rather than

t N

Wall panels

Stair

Roof tee

L beam

Inverted tee

Floor tee

Flat panel

Column

Brick panel

Brick column

Architectural panel

Architectural column

Total

Note: I ft = 0.3048 m .

.,...,_

FIRST FLOOR OFFICE

Fig. 5. This ground-level diagram shows how the tight L-shaped space was used.

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193

22

45

2

52

222

15

33

27

56

26

24

719

Thickness (ft)

12

10

32

24

I

3 1

32

8

24

I

16

47

84

I 24

I Width (ft) -

I lOto 14

4

10

I

2

-

10

10

2

13

5

7

3

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Table 2. Precast concrete components for parking garage section.

Type of component Number of components Thickness (ft) Width (ft)

Column 21

Brick column 18

Stair 19

R-beam

Brick panel 38

Wall 28

Floor tee 144

Roof tee 46

Inverted tee 22

Lite wall 34

L-beam 5 Flat slab 12

Spandrel 21

Planter wall 19

Bollard 12

Tota l 440

Note: I ft = 0.3048 m.

dirt and direct the water away from the structure. Precast perimeter walls were installed below grade as an earth­retention sys tem . This allowed the construction team to progress with the foundation quicker, as the precast

24 2

24 6

8 6

15

8 10

10 13

24 10

32 10

24 3

10 12

14 2

8 12

8 6 12 7

19 3 L

components cou ld be cast while the foundation was being dug.

The project's structural system con­sists of precast shear walls resting on drilled-pier foundations. Connections include 922 #11 grouted splice sleeves

to resist Zone 2A seismic forces. Splice sleeves were used to ensure the splices did not expand outside of the column it­self as the columns got higher and thin­ner. The thin tops of the columns would have made them difficult to pick up at their full height, especially with the trapezoidal-shaped components, so the thinner sections were spjjced to the top.

An expansion joint was placed on the south side of the building. By doing so, the design team was able to take all of the horizontal shear for the structure through the shear walls in the core and then below grade take it into the perimeter walls. In this way, no additional shear walls were needed in the office structure, thus maintaining the open spaces.

ARCHITECTURAL PRECAST CONCRETE ADDS

AESTHETIC APPEAL The precast structural system for the

office allowed work to progress quickly, as it keyed off the already placed parking structure beneath. This

Fig. 6. The combination of brick and metal cladding on the parking garage (foreground) along with precast rooftop accents on the office help the structure blend in with the neighboring bui ldings.

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Fig. 7. Vertical accents in the parking structure's stair towers reflect the verticality of nearby taller buildings.

allowed the designers to take advan­tage of economies of scale in produc­ing precast components, further reduc­ing the budget. In addition, precast architectural panels became a key ele­ment in designing the facade , which combines large expanses of glass, cur­tain wall and brick. These worked in harmony to create a variety of visually attractive elements, including a curv­ing center entry pavilion and precast detail at the roof that includes a large overhang.

The brick facade was created by ap­plying thin brick pieces to precast pan­els, which reduced the cost, speeded up construction and met the owner's desire to blend in with the surrounding buildings. The neighborhood has an eclectic look, i ncl udi ng a precast building directly across the street that also was designed by the same archi­tect and precaster. However, the de­signers agreed with the owner that the building should reflect the look of the older, richer structures in the area , which were brick-faced.

Grout joints were left gray to match standard mortar colors, while the acid­etched white cement portions had to be separated carefully in production to avoid color infiltration between them. Designing with these thin-brick panels

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JOINT TO MATCH JOINT BETWEEN BRICK

4" RECESS

1'-J 5%

Fig. 8. Section detail showi ng th in-br ick facing on precast panels.

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was complicated by the designer ' s in­terest in adding complex details such as brick wraps at the corner, soffits and finishes on all sides in brick as well as an entry pavilion with radiussed sur­faces (see Figs. 8, 9 and 10).

BRICK PIERS CHALLENGING A particular challenge arose in pro­

ducing the brick piers that conclude at the fifth level of the building with pre­cast and cast-stone capitals supporting an imposing precast overhanging cor­nice. The cornice, which projects out 6 ft (1.8 m) over the structure, gives the building a definitive termination and provides effective sun-shading. The 60 ft (18.3 m) long double tees had more camber than anticipated -as much as 2 in. (51 mm). This cam­ber created fit-up challenges where the full height windows span between the camber floor and the cornice and where the windows met the cast stone capitals. This did not affect the struc­tural integrity of the building, but it did affect the architectural detail and its true elevation.

The "hat" shape at the top of the entry consists of an L-shaped spandrel and eyebeam in one that forms the structure for the roof, providing both function and decoration (see Fig. 11). It produced structural and casting challenges that were met in design considerations and in the field to achieve the striking visual addition for the roofline that was desired.

The curved entry pavilion also pre­sented challenges for achieving the proper radius (see Fig. 12). Although the design team had worked with curved precast structures previously, creating one with the brick finish meant paying strict attention to toler­ances and making some connection adaptations in the field. As the struc­tural engineer also served as the spe­cial inspector for the city, engineers were on site most construction days and were readily available to ensure erection went smoothly.

SEQUENCING WAS CRITICAL

All of this work had to be accom­plished within the constraints of a building that was designed to be built right to the edges of the property. To

September-October 1997

~ ~

-T WOOD NAILERS AND 1/8" 1/8" EXP. BOLTS BY OTHERS

3/4"

,._ I

1-1 ci g;;

"' OJ ·..,.""""

I

h "' I

"' 1'-6" ,.,

I 1-1

~ ..., ,., :;:;. ::

!\~~ ... ,\ -f{-3/4"

7'-Cf'

Fig. 9. Connection detail between panel and tee.

1/t'± JT. 5' -11 5/8" 1/t'± JT.

1'-11 13/16" 1'-Cf' 1' -Cf' 1'-11 13/16"

3/4" JT. 1'-11 9/16" 2'-Cf'

3/4" JT. 1'-11 9/16"

END OF CORBEL 1 Cf' let' END OF CO BEL

6" 6"

FACE BRICK (2) BE-44 6"x1/4"x0'-6" MASTJCORO PAD w/ 1 5/16"f HOLE CTR'O.

Fig. 10. Connection detail for architectura l panel.

achieve the needed maneuvering room, a staging area was created five blocks away on an open lot.

The precast components were man­ufactured at CSR Quinn's plant in

Marshall, Missouri. They were deliv­ered to the project site by truck trailer, a distance of about 90 miles (144 krn) .

The precaster delivered ten loads of precast components to the staging

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Fig. 11. The distinctive roof overhang was created from an L-shaped spandrel that provides function and decoration.

area to prepare the components for erection. These were then taken to the site and lifted into place, with the truck then returning to prepare for an­other delivery. Each trip was escorted by police vehicles to facilitate mov­ing through traffic and ensuring no

accidents occurred along this short path.

Work started away from the streets and worked toward them. As the structure neared completion and less space was available on the site, se­quencing became critical to ensure

Fig. 12. Overview of construction showing erection of precast/prestressed elements.

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each piece arrived exactly as needed. Work progressed until only two bays were left to be erected. At this stage, the street was shut down except for one lane, and the erection crane was positioned in the street to finish the project.

Erection of the precast components took place between July 1995 and March 1996 (see Fig. 12). The office building was completed in January 1996 and the parking structure was finished only 6 weeks later. The facil­ity was opened for occupancy in July 1996. As expected, during the past year the facility has performed well and the building has become a distinc­tive landmark in downtown Kansas City (see Fig. 13).

The total cost of the building com­plex was $13 million. The precast work (production, delivery and erec­tion) amounted to $3,443,000.

CONCLUDING REMARKS

The judges in the PCI Design A wards Program agreed that the build­ing made a unique statement, as they honored it as a co-winner of the 1997 Award for Best Office Building. In be­stowing the award, the judges said:

"This building makes extensive use of precast concrete in the structure and its cladding, but its distinctiveness does not stop there. The design solution is more than just a fully integrated ap­proach to using precast concrete; it is in fact an aesthetically pleas­ing scheme that creates a very light, airy building due to the combination of a curtain wall and precast panels. The use of precast concrete in the roof eyebrows cre­ates an unusual three-dimensional quality that most buildings of this scale have not attempted to work into their designs. And it is a thor­oughly delightful, articulated building using a combination of precast concrete and brick."

Many challenges had to be met on this project to create the most effective structure, architectural design and erection logistics. The key to the solu­tion came in the close coordination be­tween the design and construction

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Fig. 13 . Curved thin-brick-faced architectural panels add elegance to new 333 West Eleventh Street office building.

teams during the design and erection phases of the job. The project com­prises a mosaic of precisely articulated textures as a result of the careful inte­gration of metal curtain wall, brick, cast stone and architectural precast concrete components. The new facility takes its place comfortably in a down­town neighborhood of both old and new buildings.

September-October 1997

CREDITS Owner: Broadway Square Partners, Kansas City, Missouri

Architect: BNIM/CDFM2 Architects, Kansas City, Missouri

Engineer: Structural Engineering Associates, Kansas City, Missouri

Contractor: J.E. Dunn Construction Co., Kansas City, Missouri

Precast Prestressed Concrete Manufacturer: CSR Quinn, Marshall, Missouri

Office Precast Designer: Frontrange Design Group, Arvada, Colorado

Garage Precast Designer: Bob D. Campbell Engineers, Kansas City, Missouri

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