Types of frame based on its material

8/7/2019 Types of frame based on its material

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CHAPTER II

Types of Frame Based on Its MaterialA. Bamboo frame

In general, part of the building which can be build from bamboo is cheaper

than other material building for the same purpose. The bamboo itself can be found

easily in Indonesia. Some buildings using bamboo as a material component of the

building can be seen in the pictures below.


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a. The advantages of bamboo as frame of building:1. Bamboo has a high strength; the tensile strength can be compare

with steel. However this highly strength has not been used well

because usually stalks of bamboo structure are connected withrope or wedge that have a low strength.

2. The shape of bamboo is pipe, so that the humadity is high.Because of that the bamboo is goog enough for carry the

bending moment. The characteristic of bamboo has a high

durability against the wind and earth-quake.


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b. The disadvantages of bamboo as frame of building1. Bamboo can be burnt easily, however there is a way to keep

the bamboo resist to the fire, but the cost is too expensive.

2. The strength of connection on bamboo generally is veryweak because the connecting process frequently is done

conventionally using hammer, peg, and rope. On the

conventional connecting process, the fiber which is parallel

with low friction causes bamboo broken by nail or peg.

Connecting with rope depends on the workers skill.

Connection strength is based on friction between rope and

bamboo or one to another bamboo.

Thus, conventional connecting will lower the strength of

bamboo then its strength cant be used optimally. While the

rope is loose because of changing caused by temperature,

the friction will be decreased then the construction may

collapse. Therefore connections on bamboo which use rope

must be checked periodically and the ropes must always be

setted in order to not loose.

The application of bamboo

- Roof trussRoof truss structure made of bamboo is traditionally used to consist of ridge,

rafters and beams gording using a connection from rope fiber or wedge with low

strength. To widen the roof will require an additional pile in the middle. Many

research and development has been done, even the truss of bamboo which

strengthened with steel plate and fill the connection with the mortar (cement and

sand) are able to resist the load of 4 tons. Below are examples of bamboo truss

with span 12 m along with examples of truss that connections reinforced with

fillers.


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Figure 1.1 bamboo truss

Figure 1.2 bamboo connections with fillers (Morisco & Marjono (1996))

B.Steel frameCold-formed steel (CFS) is lightweight, easy to handle, cost

effective, and a high quality alternative to traditional residential framing

materials. CFS offers the builder a strong, dimensionally stable, easy-to-work framing system whose use can be traced back to 1850.

a. The advantages of steel frame1. Consistent Material Quality2. Non-Combustible Material3. Dimensionally Stable in any Climate


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4. Insect Resistance and steel will not Rot5. High strength, so can reduce the dimension and its own weight

of the structure. it is quite beneficial for high rise building, the

long structure of bridge, or other building which build on the

bad soil condition.

6. High durability.7. The elasticity, based on Hooke law that steel has a high tension

because of its elasticity.

8. High ductility, because the steel which receive high tensile willhad high strain before the collapse.

9. Easily to connect with other member of each element usingweld or bolt.

10. The implementation process of construction is faster thanother material.

b. The disadvantages of steel frameEven though steel frame has a lot of advantage, but its also has

some disadvantage, especially in terms of maintenance, such as steel

structure which directly contact with air or water, periodically should

be painted. The protection against the fire hazard also important,

because the strength of steel material will be weaken drastically as the

effect of the temperature rise highly, the others weakness is buckling

problem which is a function of the slimness of a section

Environmentally Sensitive

All steel products are recyclable! The overall recycling rate for steel

products in the US is 60%. Insteel building products,the minimum recycled

content is 25%. This recycling is accomplished with no degradation in product

quality or loss of properties. A contributing factor in the steel industrys ability to

achieve significant recycling is that magnetic separation is the easiest and most

economical method of removing steel from the solid waste stream. The amount of

energy needed to produce a ton of steel has been reduced by 34% since 1972.

Steel Framing Components


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The steel component known as the structural C is the predominant shape for

framing floors, walls, and roofs. The primary difference from one use to another is

the thickness of the steel and the depth of the member.

Floors Builders commonly opt for steel floor joists ranging in depth from 6- to

12-inches and steel thickness from 0.034- to 0.101-inches. Instead of using

overlapped joists at a center support, a single length of steel joist is commonly

used to span continuously.

Walls There are two basic types of studs:

Structural C studs for interior and exterior load-bearing walls that range in

depth from 2 to 8 to accommodate the necessary insulation thickness and


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ranging in thickness from 0.034- to 0.071-inches depending on the anticipated

load.

Drywall studs for non-load-bearing partitions that range in depth from 1- to 6-

inches and metal thichness ranging from 0.01- to 0.034-inches. The thermal

efficiency of the steel-framed exterior walls may be increased by installing

insulation board on the exterior of the wall.

Roofs The broad range of available sizes and thicknesses allow steel framing to

be used in virtually any roof system. Steel trusses can be built on-site or off-site in

truss fabrication plants.


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Framing Methods

There are three basic residential steel framing methods: stick-built,

panelized, and pre-engineered.

Stick-built - Replace wood members with steel members (one-for-one

replacement). As shown below, the steel-framed non-load-bearing wall appears

very similar to that of a comparable wood-framed wall.

Panelized - Factory-assembled panels delivered to site and connected together.

The panelized approach represents an efficient approach for repetitive building

designs and, as a result, is a popular approach in hotel/motel construction and

other multi-unit applications.

Engineered - Location and placement of framing members is engineered to take

advantage of steels properties. Spacing of framing members may increase to as

much as 8-feet with horizontal stabilizers.

Barriersto Steel Framing

Five key barriers to the expansion of residential steel framing have been

identified.

Cost of Construction

Distribution Infrastructure

Standardized Product


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Consumer Preference

Thermal Performance

Reinforced Concrete Frame

In this modern area, concrete is the one mostly be used. The concrete

itself obtained by mixing cement, fine agregate (sand), coarse agregate and water.

Due the chemical reaction between the cement and water, concrete set into

atrificial stone and as the result, the mixture will binds the constituents together as

a pasteor matrix. Fresh concrete can be molded into any shape, after hardening

period an curing in 28 days, the concrete will take its optimum strength. But

concrete has a weakness through tensile strength, so that the steel bars is provide

to overcome this weakness by plant the steel bars in concrete to form a composite

material called reinforced concrete.

The strength achived will depend on this factor, such as :

a. Type of cement used.b. Type and size of agregates.c. Water.d. Use of admixtures.e. Water/Cement ratio.f. Grade strength.

Reinforced concrete (RC) frames consist of horizontal elements (beams)

and vertical elements (columns) connected by rigid joints. These structures are

cast monolithically that is, beams and columns are cast in a single operation in

order to act in unison. RC frames provide resistance to both gravity and lateral

loads through bending in beams and columns (Figure 2). There are several

subtypes of RC frame construction:

onductile RC frames with/without infill walls

onductile RC frames with reinforced infill walls


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Ductile RC frames with/without

infill walls

Figure 2: A plan of a typical RC

frame building in Ahmedabad,India; note the portion that

collapsed in the 2001 Bhuj

earthquake (WHE Report 19, India)

Figure 4: Features

of nonductile RC

frame construction

in Taiwan (WHE

Report 61)

SEISMIC PERFORMANCE

Some earthquakes around the word have revealed the following patterns

of damages and failures in RC frame construction:


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Shear failure and concrete crushing failure in concrete columns. These are the

most undesirable nonductile modes of failure (Figure 5). This behavior can lead to

the loss of gravity load-bearing capacity in the columns and potentially a total

building collapse.

Figure 5: Shear failure of a reinforced concrete column in the 2001 Bhuj

earthquake (WHE Report 19, India)

Partial ductile design and detailing. Systems that exhibit some (limited) yielding

behavior can eventually form dangerous collapse mechanisms as a result of

stiffness or strength degradation at sections without ductile detailing.

Conceptual design deficiencies. This includes such deficiencies as incomplete

load path and architectural planning deficiencies such as vertical and/or horizontal

irregularities. Architectural features play an important role in the performance of

RC frame buildings.

Inappropriate column/beam relative strengths. This can lead to failure of

individual members and connections when the weak column-strong beam

mechanism develops.

Inadequate detailing of reinforcement.

Soft-story effects. In many applications, architectural considerations result in a

taller first story, which causes a soft-story formation due to drastic change in the

stiffness between adjacent stories (Figure 6). The presence of a soft story results

in a localized excessive drift that causes heavy damage or collapse of the story


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during a severe earthquake (Figure 7). Another typical case of soft story arises

when the first floor is left open (that is, no infills) to serve a commercial function

(stores) or as a parking garage (very common in Turkey, India, and Cyprus), while

upper floors are infilled with unreinforced masonry walls. A relatively rare case

results when the strength of the two adjacent stories is significantly different

(weak story) leading to localized deformations similar to the soft-story

mechanism.

Short-column effects. The short- or captive-column failure occurs due to partial

restraining of the columns that are, in turn, subjected to high shear stresses and

fail in shear if unable to resist these stresses.

Figure 6: Soft-story mechanism

(WHE Report 61, Taiwan)

Figure 7: Building collapse due

to soft-story mechanism in the

2003 Boumerdes earthquake

(WHE Report 103, Algeria)

In several instances, seismic performance of RC frame buildings has been

quite poor, even when subjected to earthquakes below the design level prescribed

by code. One of the underlying reasons is the absence of an effective mechanism

for code enforcement in some countries. This deficiency in governmental

oversight is linked to several related factors, such as the lack of technical control


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Figure 8: Jacketing of RC frame members (WHE Report 11, Colombia)

Figure 9: Illustration of seismic strengthening with addition of RC infill walls

(WHE Report 62, Taiwan)

An alternative procedure which has been recently developed for RC frames with


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unreinforced masonry infill walls proposes the use of carbon-fiber, reinforced

polymers (CFRP) applied on existing unreinforced masonry infill walls (Figure

10) to increase the overall lateral load capacity. Although its cost is higher, this

method is easy to apply and much faster when compared to the installation of new

concrete infill walls.

Figure 10: Strengthening of brickinfilled RC frame

with CFRP

C. Timber FrameyProtection of Materials

Lumber, panel products and millwork (windows, doors and trim) should

be protected from the weather when delivered at the building site. Preparation of

a construction schedule will assure that lumber and millwork are delivered as

needed. Follow these simple rules:

1) Support framing lumber, plywood and panel products at least six inchesabove ground and protect them below and above with a waterproof cover

such as plastic film. Finish lumber and flooring, particularly, are to be

protected from ground or concrete slab moisture and kept under cover

preferably indoors until installation.

2) Store door and window assemblies, siding and exterior trim inside. Wherethis is not practical, these materials are to be elevated from the ground and

protected above and below with a weatherproof cover. Millwork items are

often pre-treated with a water repellent preservative as received. Whether

treated or not, such materials are to be stored under cover.

3) Untreated exterior millwork should receive a water-repellent preservativetreatment before installation. Store interior doors, trim, flooring and

cabinetwork in the building. Where wet plaster is used it must be

permitted to dry before interior woodwork, cabinetry and flooring are


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installed.

Types of frame construction from timber

1. PLATFORM FRAMEIn platform-frame construction, first floor joists are completely

coveres with sub-flooring to form a platform upon which exterior walls

and interior partitions are erected. This is type of construction is

commonly used in home building. Platform construction is easy to erect.

Its provides a work surface at each floor level and is readily adapted to

various methods of prefabrication. In platform systems it is common

practice to assemble wall framing on the floor and tilt the entire unit into

place.

Platform frame


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2. BALLON FRAMEIn balloon-frame construction, exterior wall studs continue through the

first and second stories. First floor joists andexterior wall studs both bear on

the anchored sill. Second-floor joists bear on a minimum 1x4-inch ribbon

strip, which has been let-in to the inside edges of exterior wall studs.

In two-story buildings with brick or stone veneer exteriors, balloon

framing reduces variations in settlement of framing and the masonry veneer.

Where exterior walls are of solid masonry, balloon framing of interior bearing

partitions also reduces distortions in door and closet openings in crosswalls.

The requirement for longer studs, and the difficulty in accommodating current

erection practices and firestopping, has reduced the popularity of this system.

Ballon Frame


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3. FASTENINGNails, used alone or in combination with metal framing anchors and

construction adhesives, are the most common method of fastening 1- and 2-

inch framing lumber and sheathing panels. Ring or spiral shank nails provide

higher load-carrying capacities than common nails of the same diameter, and

are particularly useful where greater withdrawal resistance is required. Nailed

joints provide best performance where the load acts at right angles to the nails.

Nailed joints with the load applied parallel to the nail (in withdrawal) should be

avoided wherever possible, since joints are weakest when nailed in this

manner.

Where tilt-up wall framing is not practical, or where stronger stud-to-plate

attachment is required (as in the use of rigid foam sheathing), toe-nailing is the

most practical method of framing studs and plates. In toe-nailing, nails are

driven at a 30-degree angle (approximately) to the stud. Studs can be pre-

drilled to simplify this operation and prevent excessive splitting.

Method of loadingnails

Sizes off common wire nails


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4.ROOF AND CEILING FRAMINGRoof construction must be of adequate strength to withstand anticipated

snow and wind loads. Framing members must be securely fastened to each

other, to sheathing and to exterior walls to enable the roof system to serve as a

structural unit.

roof framing gable overhang and flat roof framming

Valley Rafter Roof Framing

Hip Rafter Roof Framing

Roof Framing at Eave


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Shed Dormer Roof Framing Gable Dormer Framing

Roof Trusses

Roof framing may be fabricated as light trusses and installed as complete

units. Such framing is designed according to accepted engineering practice. The

truss members are joined together by fasteners such as nails, nails and glue, bolts,

metal plates or other framing devices.

Use of roof trusses eliminates the need for interior bearing partitions and

frequently results in more rapid installation of roof and ceiling framing. Roof

trusses are generally spaced 24 inches on center. Where roof trusses are used,

gable ends are usually framed in the conventional manner using a common rafter

to which gable end studs are nailed. Eave overhangs are framed by extending the

top chords of the trusses beyond the wall.

Where hip and valley construction is required, modified trusses or

conventional framing are used to meet the condition.

Ceiling-Floor-PartitionSeparation

In some localities truss uplift may be a problem. This problem is

characterized by the separation of the floor or ceiling from an interior partition. A

widely used technique to minimize truss uplift separation is to allow the gypsum

board ceiling to float or rest on the partition and remain unattached to the truss

on either side of the partition. In cases where trusses are perpendicular to


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partitions, the gypsum board ceiling remains unattached at least 18 inches from

the ceiling/ wall intersection.

FlatRoofs

Flat roofs should be avoided if possible because they are difficult to

ventilate and insulate adequately and present weather proofing problems. Flat roof

joists are securely nailed to exterior wall plates and to each other where they join

over interior partitions.

RoofSheathing

Wood structural panels or 1-inch board lumber provides a solid base for

roof coverings. Structural panels are manufactured in various thicknesses and are

usually 4x8' in surface dimension. Recommended spans, spacing between panel

edges and thickness are stamped on the panel face. Structural panels are installed

with the long dimension perpendicular to rafters and with the panel continuous

over two or more spans.

Spaced Sheathing

Where wood shingles or shakes are to be applied as the finished roof, solid

sheathing is used or nominal 1x4 lumber is nailed perpendicular to rafters and


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trusses with each board spaced a distance from the next board equal to the weather

exposure of the shingles or shakes. (5 inches is common exposure for shingles.

Shakes may be exposed 7 to 13 inches depending on their length.) Because shakes

are not smooth surfaced, an 18-inch wide underlay of asphalt felt is used between

each course. Where wind driven snow is encountered, solid sheathing and Type

15 asphalt felt are used under wood shakes.

Ventilation ofAttic Spaces

Ventilation of all attic spaces is required to eliminate moisture

condensation on roof framing in cold weather and to permit heat to escape in

warm weather.

For gable roofs, a screened, louvered opening is used which provides a net

open area of 1/150 of the area of the ceiling below. Where a -inch wide screened

slot is also provided in the eave soffits, or where a vapor retarder having one perm

or less permeability is installed on the warm side of the ceiling, the total

ventilating area may be reduced to 1/300 of the ceiling area. With hip roof

construction, a -inch wide screened slot in the eave soffits, and ventilator at the

ridge to provide 1/450 inlet and 1/900 outlet fractions of the ceiling area below,

assures adequate ventilation. For flat roofs, blocking, bridging and insulation are


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arranged to prevent obstruction of air flow. Such roofs are ventilated at eave

soffits to provide net open area equal to 1/250 of the area of the ceiling below. A

vapor retarder of one perm or less permeability is applied under the ceiling finish

below flat roofs.

Advantages

The use of timber framing in buildings offers various aesthetic and

structural benefits, as the timber frame lends itself to open plan designs and allows for

complete enclosure in effective insulation for energy efficiency. In modern construction

timber-frame structure offers many benefits:

y it is rapidly erectedy it lends itself well to prefabrication, modular construction and mass-production.y an "average"-sized timber-frame home can be erected within 2 to 3 days.y the frame can be encased with SIPs for the drying in: that is, ready for windows,

mechanical systems, and roofing.

y it can be tailored to suit customer tastes and creativity such as carvings orincorporation of heirloom structures such as barns etc.

y it can use recycled or otherwise discarded timbers.y

it offers some structural benefits as the timber frame, if properly engineered,lends itself to better seismic survivability. Consequentially, there are lots of old

half-timbered houses which still stand despite the foundation having partially

caved in over the centuries.

Disadvantage

y poor prevention of capillary movement of water within any exposedtimber, leading to afore-described creep, or rot

y timber ends, joints and corners poorly protected through coatings, shape orposition

y non-bevelled vertical beams (posts and clapboards) allow water absorptionand retention through capillary action.

y Noise from footsteps in adjacent rooms above, below, and on the samefloor in such buildings can be quite audible. This is often resolved with


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built-up floor systems involving clever sound-isolation and absorption

techniques, and at the same time providing passage space for plumbing,

wiring and even heating and cooling equipment.

y Other fungi that are non-destructive to the wood, but are harmful tohumans such as black mold. These fungi may also thrive on many

"modern" building materials.

y Wood burns more readily than some other materials, making timber-framebuildings somewhat more susceptible to fire damage.


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tension or compression. Consequently, all material in any given element

is utilized to its full extent. Furthermore, most space frames are now

constructed with steel or aluminum, which decreases considerably their

self-weight. This is especially important in the case of long span roofs

that led to a number of notable examples of applications.

2. The units of space frames are usually mass produced in the factory so

that they can take full advantage of an industrialized system of

construction. Space frames can be built from simple prefabricated units,

which are often of standard size and shape. Such units can be easily

transported and rapidly assembled on site by semi-skilled labor.

Consequently, space frames can be built at a lower cost.

3. A space frame is usually sufficiently stiff in spite of its lightness. This is

due to its three dimensional character and to the full participation of its

constituent elements. Engineers appreciate the inherent rigidity and

great stiffness of space frames and their exceptional ability to resist

unsymmetrical or heavy concentrated load. Possessing greater rigidity,

the space frames also allow greater flexibility in layout and positioning

of columns.

4. Space frames possess a versatility of shape and form and can utilize a

standard module to generate various flat space grids, latticed shell, or

even free-form shapes. Architects appreciate the visual beauty and the

impressive simplicity of lines in space frames. A trend is very

noticeable in which the structural members are left exposed as a part of

the architectural expression. Desire for openness for both visual impact

as well as the ability to accommodate variable space requirements

always calls for space frames as the most favorable solution.


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Roof framing for a circular dome.

JointingSystems onSpace Frame

The important thing on space frame are jointing systems the member of

space frame, space frame can be build without connecting the member together.

The type of jointing depends on the connecting technique, whether it is wolding,

bolting, or apllying mechanical connectors. The technique itself is affected by

shape of the members.

Threre are the requirements for jointing systems on space frame:

a. The joinst must be stiff and strong.b. The eccentricity at a joint should be kept to a minimum, yet the joint detailing

should provide for the necessary tolerances that may be required during the

construction.

c. Joints of space frames must be designed to allow for easy and effectivemaintenance.

All connectors can be divided into two main categories: the purpose-made

joint and the proprietary joint used in the industrialized system of construction.

The purpose-made joints are usually used for long span structures where the

application of standard proprietary joints is limited. An example of such types of


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joints is the cruciform gusset plate for connecting rolled steel sections as shown

below.

Connecting joint with cruciform gusset plate.

A survey around the world will reveal that there are over 250 different

types of jointing systems suggested or used in practice, and there are some 50

commercial firms trying to specialize in the manufacture of proprietary jointing

systems for space frames. Unfortunately, many of these systems have not proved

attainment of great success mainly because of the complexity of the connecting

method. These table give a comprehensive survey of the jointing systems all over

the world. All the connection techniques can be divided into three main groups:

(1) with a node, (2) without a node, and (3) with prefabricated units.


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B.Skeleton FameThe skeleton frame consist of identical elements fastened to each other to form

a system of parallepiped-shape cells, each cell being bounded by four frame

elements which at least in part common to two contigously juxtaposed cells.

The cells may be freely cantilevered from upright pillars or freely span

distances between pillars which are multiples of the horizontal dimention of

one cell.

Figure 1 is a perspective and partly exploded partial view of a building

including a skeleton frame of the invention.


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Note :

1.

Rectangular frame elements(horizontal beam and column)

2. Floor plates3. The ceiling of the lower

building portions

4. Wall panels5. Wall panels6. The suspended of floor plates7. Web portion8. Flange portions9. Lugs

10.Lugs11.

Bores for connecting the bolts

12. The notches13.Four L-shapes sections14. Terminal integral flanges15. Aperture plates16.17.Reinforcing angles18.Bars19. Pairs of wedges


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CONSTRUCTION TECHNOLOGY

By:

Anita Tri Rahmawaty

110905019Y

Construction Management 2009

STATE POLYTECHNIC OF JAKARTA


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