Example Project

Подпись: Copyright © Marcel Dekker, Inc. All rights reserved.A 14-story concrete building is to be located at 1601 Pennsylvania Avenue, Washington, D. C. Building size is approximately 22,500 ft2 (2090 m2) per floor. Floor slabs are 8-in. (203.2-mm) flat slab with drop panels at every column. Column sizes and locations vary due to the existence of a three-story high entrance, free from columns. Story heights vary from 14.5 in. (368.3 mm) for the first three floors to 10.5 in. (266.7 mm) for the remain­ing eleven stories. There are no cantilevered balconies, and the slab on grade will not be in place before forming operations start. The building is located in a highly restricted downtown area.

Existing buildings and traffic limit the movement of equip­ment on all sides of the building. The area has a highly qualified labor force and high hourly labor costs.

Formwork system Influence factor

Conventional wood system

Conventional metal system

Ftylng truss system

Column-mounted shoring system

Tunnel form

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Slab type

All slab systems

Most suited for two-way slab supported by beams or one-way slab, beam, girder

Two-way: flat plate and flat slab

One-way: slab supported by beams or walls and

Joist slab (standard or skip-joist)

One-way slab supported by wa! l3 Less then 12-in. thickness

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Compatibility with lateral load supporting system

Compatible with all lateral load supporting systems

Generally not suitable for framed lube end tube In lube because ol the close distance between columns which characterize the lube systems

Bearing wall

Horizontal

uniformity/

irregularity

Can handle variations In beam size and location Can handle variations in cantilever shape, size, and location Avoid cross beams

Beams should be of the same size and location or wilhin 20% difference from floor to floor Cantilever should be of the same size and location or within 20% difference from floor to floor

Beams should be of the same size and location Cantilever balconies should be of the same size and location

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Vertical

uniformity/

irregularity

Can handle variations of cofumn/wall size

and location.

Сал handle variations in story height within one floor or from floor to floor.

Column/wall should be ol the same size and location or within 20% difference from floor to floor Can handle limited variation (20%) In story height

Walls should be of the same size, location, and height from floor to floor

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High stories (higher than 14 ft)

Not suitable for high stories

More suitable for high stories (light alum, wt.}

Limited by truss depth ( Up to 20 ft)

Height independent system

Limited height system (between 7.5 and 10 ft)

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Openings

System can handle variation In opening size and

location

Can handle limited variation (20%) In opening size and location

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Slopes and cambers

Slopes and cambers can be accommodated at additional cost

System must be designed to accommodate slopes and cambers

Slopes end camber must be identical from floor to floor

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HVAC

Can accommodate extensive HVAC

Cannot accommodate extensive HVAC

HVAC should be minimal and identical from lloor to floor

Dimension

Limitations

Used for small building size (less than 100,000

Used for medium building size (between

100,000 and 200,000

ft1)

Used for large size buildings (more than 200,000 fl7}

Formwork

^^^system

Influence factor4*4^

Conventional wood system

Conventional metal system

Flying truss system

Column-mounted shoring system

Tunnel form

Job specification

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Fkxxcycle (number of floors /day)

Typically iloor ©very $ working days Faster cyde can bo accommodated at addilional cost (increasing number of stones lo b© shored and restored)

Floor ©very 3-4 day

Floor every 1-2 days

Aatool ptaoemenl

Сеоегаїу. nd a major lacier In horizontal concrete work, average raio between 25-30 cydcs/hcurs

Construction

sequence

Pouring columns, then beams and slabs Slab on grad© is nol necessarily Ю b© in place, but cost can be reduced if slab on grad© is in place

Pouring eoiumrw. ihon beams and slabs Slab on grad© should be in place for ihe form lo be used in Ttrsi door

Pouring columns, then beams end slabs Slab on grado is nor necessarily to be in place

Pouring stabs and walls logolher З-in. slarterwad a necessarily

Local conditions

At

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Work best in areas of high-quality, lew*cost labor force

Work best in areas of high – qualiy. low-cost labor force

Generally, work In areas of high-cost, low – quality labor force

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Available

storage

make-up

area

Require minimum storage and make-up area

Small make-up area is required if system is panokzod

$ii© must have adequate storage and mak©-up area

System is preassempted Minimum storage area is required.

Access lo site

Generally, not a factor for hand-sel sysiems

Job must be acessiblo for large form unis

May nol be a faclor il lorms are assembled on site

Job must be accessible for large preassembled steel lorms

Formwork system Influence lector

Conventional wood system

Conventional metal system

Flying truss system

Column-mounted shoring system

Tunnel form

Supporting organizations

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Initial ’make-up" cost

Average cost range from $1 to S3 per square foot of contact area

Average cosl range from $10 to $i5 per square foot of contact area

Average cost ranges f rom$20 to $60 per sq ua re foot ol contact area

Potential

reuse

Up to 15 reuses

Up to 20 reuses

Minimum of 12-15 reuses should be available

Minfmumof 15-20 reuses should be available

Minimum of 50 reuses should be available

Si ripping cosl

High stripping cost (approximately one*lhird of the makeup cost)

Lew stripping cost (approximately one-half of the hand-set systems

Low stripping cost

Average labor productivity

12 tt2 par contact area

18 ft2 per contact area

36 H* per contact area

46 It2 per contact area

soft1 per contact area

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Availability of crane and crane time

Can be hand-set Less expensive if crane is available

Can be hand-set Crane »$ necessary if made into panels

Adequate hoisting equipment must be available

Adjacent building traffic and other obstructions

Generally, not a factor

Generally, not a factor May be a factor il system panelized

A major factor, there must be open spece at least 1.5 ihe length of the large panel from (he face ol ihe building

Adequacy of crane carrying capacity

Generally, not a factor

Crane should have adequate carrying capacity at maximum and minimum radii.

Formwork syslem Influence laclor

Conventional wood system

Conventional metal system

Flying truss system

Column-mounted shoring system

Tunnel form

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Safely

management

Normal safety precautions are required

Special safety In dealing with crane operation

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Supervision

•Troubleshooting

experience*

Min. engineering supervision

Requires skilled crew

Requires moderate engineering supervision

Requires high engineering supervision

Requires high degree of engineering supervision

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Supporting yard

Min. yard is required

Requires local yard

Requires enough supporting local or

System should be

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facility

il made into panels

regional yard facility

area

No yard is requried