CarbonCast® Double Tee

The CarbonCast® Double Tee in 12'-width and 15' and 16' MEGA-Tee widths can span up to 65'. The C-GRID carbon fiber mesh used in the flange for crack control requires less concrete cover, allowing the member to be up to 8% lighter in weight and more durable than conventional tee flanges, as carbon fiber is not vulnerable to corrosion. Keep in mind that 15'- and 16'-wide double tees easily accommodate 45'–48' bays for open and bright interiors and fewer total members than 12'-wide systems. Additionally, 16'-wide Mega-Tees are especially efficient for end bays, providing increased space for turning.

  • CarbonCast® Double Tee
  • Dry Diaphragm Connection
  • Stacked in Yard
CarbonCast® Double Tee

Quick Points

  • Up to 8% lighter than conventional tees
  • Reduce superstructure and foundation requirements
  • Eliminate the need for chemical sealers and corrosion inhibitors
  • Reduce the carbon footprint of parking garages
  • Offer superior durability, strength and crack control
  • Produced under an agreement with AltusGroup, Inc.

What Are Double Tees?

MEGA-Tee© precast double tees form the main traffic and driving surfaces in parking garages, and may be used as decking and roofing elements on other structures. High-strength precast concrete offers corrosion resistance and long-life. Larger 15’- and 16’-wide tees reduce the number of joints and, combined with stem stressing, help provide a pleasant driving experience.

In CarbonCast© double tees, traditional steel mesh reinforcing is replaced with carbon fiber. By eliminating carbon steel from the corrosion zone, CarbonCast© tees offer longer-lasting performance. These tees require less concrete cover, lowering weight by six percent with possible reduction in foundation requirements.

Benefits of Precast Double Tees

When you invest in precast double tees, you’ll benefit from:

  • Fire resistance — One- and two-hour fire-rated designs are typical; 4-¾” flanges are no longer required by code for two-hour designs.
  • Fast-track production — Because these components are precast, they arrive on site ready to be erected. In turn, this reduces site congestion and allows buildings to be closed in more quickly. Components can be installed in almost any weather.
  • Structural durability — Superior corrosion resistance means that you won't have to worry about your structure showing premature signs of wear and tear. With proper maintenance, precast concrete can lower maintenance costs over the life of the garage.
  • Larger members — 15’- and 16’-wide double tees reduce shipping and erection costs and save time on the job, while providing larger, more open interiors and turning radii for easier and safer navigation.
  • Design flexibility — Select features such as warping and cast-in drain bodies for superior drainage; and post-tensioned lateral reinforcement to provide effective lateral load resistance while doing away with most field-applied pour strips that bring the potential for corrosion of diaphragm reinforcing steel.

Maintenance

CarbonCast Double Tees shall be kept free of dirt, debris and chloride-laden water. Snow removal equipment shall use a rubberized blade guard. Total distributed weight of such equipment shall not exceed 50 lbs/sq.ft.

Manufacturing

CarbonCast Double Tees will be manufactured in accordance with PCI guidelines in a PCI-certified precast manufacturing facility.

Contact Us Today for Your Free Quote

If you have any questions about double tees or other components, contact the High Concrete team today. With nearly 60 years of experience, we know what works. Together, we'll help you find the materials you need to build to achieve your design vision.

Connections

Connections for seismic diaphragm may be welded or field-topped pour strips

  • Tee to spandrel – pocket or haunch (corbel) gravity connection

Welded (diagram)

Field-topped pour strip (diagram)

 

  1. Tee to wall – lateral connection

Welded (diagram)

Field-topped pour strip (diagram)

 

  1. Tee to inverted “T” girder – lateral connection

Welded (diagram)

Field-topped pour strip (diagram)

 

  1. Tee to tee – lateral connection, welded, using Vector Connector® or equal connection device

Welded (diagram)

Concrete

Mix: 50% recycled content (per design requirements)

Water-cement ratio: </=.38

Strength: 7-9,000 psi

Color: structural buff or gray

Fire Performance

ASTM E 119

3-1/2” flange: 1 hour

4-3/4” flange: 2 hours

Reinforcing

Primary reinforcement – twelve strands 1/2" dia. low relaxation, 270ksi special, A = 0.167 in2

Flange reinforcement - C-GRID® carbon fiber mesh

Specifications

Certification . . . . . . . . . . . . . . . . . PCI Factory Certification

Design. . . . . . . . . . . . . . . . . . . . . . ACI 318-95

Prestress strand . . . . . . . . . . . . . .  ASTM A 416

Reinforcing steel. . . . . . . . . . . . . . ASTM A 615

C-GRID carbon fiber mesh . . . . . . . . . . . . ASTM A 185

Structural steel . . . . . . . . . . . . . . .  ASTM A 36

Aggregate. . . . . . . . . . . . . . . . . . .  ASTM C 33

Cement. . . . . . . . . . . . . . . . . . . . .  ASTM C 150 Materials

Dimensional Tolerances:

Length . . . . . . . . . . . . . . . . . . . . . .  ± 1/8 in. per 10 ft. 1 in. max.

Width & Depth . . . . . . . . . . . . . . . .±1/4 in.

Stem width . . . . . . . . . . . . . . . . . . . ±1/8 in.

Flange Thickness . . . . . . . . . . . . .   ±1/8 in.

Camber deviation . . . . . . . . . . . . . . ±1 in.

Horizontal alignment:

Under 40 ft., ±1/4 in.

40 to 60 ft., ±1/4 in.

Over 60 ft., ±1/2 in.

Differential Camber, prior to erection, adjacent tees: ±3/4 in.

Position of Blockouts and Inserts: ±1/2 in.

Position of Weld Plates: ±1 in.

 

Erection

CarbonCast Double Tees may be erected by PCI-certified erection crews. Tees and other parking garage components will be tested by an independent testing firm.

Options

Blockouts – prefabricated plastic forms, fit into stems to facilitate mechanical, electrical and plumbing installations (www.highconcreteaccessories.com)

Burke Lift Covers – prefabricated plastic lifter covers in standard and custom colors

Curbs – prefabricated and mechanically attached curbs for car stoppage

Custom configurations – cuts, penetrations and form alterations including warping according to design requirements

Support

Haunches – haunches or corbels may be used as support in walls. The legs of the Pretopped Double Tees will rest on the haunch.

Ledges – ledges may be used to provide support to double tee ends.

Pockets – in some applications it may be appropriate for double tees to be manufactured to fit into a preformed pocket in a wall providing a cleaner visual.

Related Work

Cast-in-place diaphragms – field-applied pour strips may be used to attain seismic diaphragm performance. This work is performed by others.

Sealers – pretopped double tee decks may be treated with a field-applied sealer to help control corrosion of mild steel reinforcement.

Sealants – caulking of double tee joints is required to ensure watertight performance of the deck. This work is performed by others.

 

Following are standard load tables for uniformly loaded simple spans. These tables are for guidance only. Individual designs may be furnished for unusual loading conditions, changes in cross section, low camber requirements, etc.

Notes

1. Load span charts are intended for preliminary design only and are based on:
(a) Horizontal single span with unrestrained ends, no cantilever
(b) Uniform superimposed live load (dead load of tee has been deducted)
(c) f’ci = 3500 PSI min. at transfer
(d) Max. extreme fiber stress in tension under full load = 850 PSI

2. Tees will be manufactured with camber. Amount varies with design requirements and will be shown on shop drawings.

3. Tee widths shown are maximums, flanges may be reduced as required.

4. Standard finishes:

TOP: as per designer’s requirements;
BOTTOM & SIDES: smooth from steel forms.

5. Consult High Concrete Group for further assistance.

6. UL ratings available upon request.

 

 Load Test Data - 15' MEGA-TEE with 26Load Test Date for 15' MEGA-TEE with 28Load Test Date for 15' MEGA-TEE with 30Load Test Data for 15'-wide MEGA-TEE with 34

Potential precast point contributions to LEED certification

Credit

Title

LEED 2009

Sustainable Sites

 

 

SSc5.1

Site Development, Protect or Restore Habitat

1

SSc7.1

Heat Island Effect, Non-Roof

1


Materials & Resources

 

 

MRc4.1

Recycled Content, 10% (post-consumer + pre-consumer)

1

MRc5.1

Regional Materials, 10% Extracted, Processed & Manufactured Region

1

MRc5.2

Regional Materials, 20% Extracted, Processed & Manufactured Region

1




CarbonCast is a registered trademakr of AltusGroup, Inc.
C-GRID is a registered trademark of Chomarat N.A.
LEED is a registered trademark of US Green Building Council.