ARCH 3501 - ARCHITECTURAL DESIGN STUDIO 4

LAURA LOPEZ + JOSE SANCHEZCOLLEGE OF ARCHITECTURE

TEXAS TECH UNIVERSITY - FALL 2008

STUDIO 703STRUCTURAL MATERIALS RESEARCH

WOOD

WOOD

TYPES + PRODUCTSIn order to better understand the properties of wood and its uses, we researched different types of wood as well as wood products & by products. Wood is made up of 50% carbon, 44 % oxygen, and 6% hydrogen.

There are two different categories of wood, softwoods and hardwoods. Under these categories there are many species and even more sub species of wood. Dependent on the species, or subspecies, wood is used in construction, as fuel, as commerical products, or as food.

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species of woodHARDWOODS

MAPLE DARk RED MERANTIBEECH OAk TEAk

Grow approximately 10-40 meters tallGrown in Asia, Europe, North America, & Northern AfricaHard maple is used in bowling pins, al-leys, cue sticks and butcher blocks

Grows approximately 20-35 meters tallGrows in North America & EuropeUsed primarily for framing & flooringTough but dimensionally unstable

Grows approximately 18-55 meters tallGrown in Northern HemisphereHighly resistant to fungal & insect attacks

Grow approximately 30-40 meters tallGrown in South & Southeast AsiaUsed for flooring & veneer

Grows up to 84 meters in heightGrown in Malaysia, Indonesia, & PhillipinesHigh class joinery, frames, & doors

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EkkIMERBAU ROBINIA

Grows up to 50 meters in heightGrown in Southeast Asia & Islands in the Pacific OceanVery durable & termite resistant

Grows approximately 4-25 meters tallGrown in North America & Northern MexicoUsed for making fences, railroad ties, & posts

Grows 16-24 meters tallGrown in tropical or subtropical moist lowland forestsUsed primarily for railway track ties

species of oodHARDWOODS

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DOUGLAS FIR SPRUCE SCOTS PINE EUROPEAN LARCH PINE

Grows approximately 20-120 meters tallGrown in North America, Mexico, & Eastern AsiaWithstands high loads well

Grows approximately 20-95 meters tallGrown in Northern temperate climatesUsed primarily in paper manufacture

Grows up to 25 meters in heightGrown in Euopre, Asia, Great Britain, Spain, & SiberiaUsed for general construction work

Grows approximately 20-120 meters tallGrown in Europe, Alps, Carpathians, Poland, & LithuaniaUsed in fencing

Grows approximately 3-80 meters tall-Grown in Northern HemisphereUsed for high value carpentry items

species of woodSOFTWOODS

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FIR WESTERN HEMLOCk WESTERN RED CEDAR

Grows approximately 10-80 meters tallGrows in North and Central America, Europe, Asia, & North AfricaGeneral timber use

Grows approximately 50-70 meters tallGrown in North AmericaUsed in timber & paper production

Grows approximately 50-75 meters tallGrowns in North America & CanadaHighly resistant to decay

species of woodSOFTWOODS

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Solid Wood ProductS

BOARD TRIO BEAMFOUR PIECE BEAMSOLID STRUCTURAL TIMBER kVH SOLID SOFTWOOD SECTION

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ROD GLUE LAMINATED TIMBER PROFILED BOARDSSOLID HARDWOOD SECTION

Solid Wood ProductS

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Wood Based Products

3 PLY CORE PLYWOOD 5 PLY CORE PLYWOOD LAMINATED VENEER LUMBERPLYWOOD STRUCTURAL VENEER LUMBER

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BLOCkBOARD ORIENTED STRANDBOARD PARTICLEBOARD WOOD-WOOL SLAB HARDBOARD

Wood Based Products

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MEDIUM BOARD POROUS WOOD FIBREBOARD BITUMEN WOOD FIBREBOARD PLASTERBOARD CEMENT FIBREBOARD

Wood Based Products

WOOD

RECIPROCAL FRAMEReciprocal frame structures are three dimensional used primarily in roof structrues. It consists of radiating beams supported by a ring beam, cloumns, or an external wall. As a result of this structural composition, the outer edges of the neams form an outer polygon or circle.

Early examples of reciprocal frame construction include Eskimo tents, Indian tepees and Hogan dwellings. Over time as mathematics developed, more possibilities were provided for the use of reciprocal framing.

RECIPROCAL FRAMES

RECIPROCAL FRAME

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The reciprocal frame is a roof structure where each beam both supports and is suported by other beams in the roof structure. A minimum of 3 breams is required to create a recirpocal roof. As each beam supports the next in a reciprocal manner no internal support is necessary.

Only the outer end of each beam requires supprot which will normalyl be a post used for the wall. The roof loads are transferred to these posts and in turn to the supporting foundation.

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RECIPROCAL FRAME

PLAN & ELEVATION

Inner radius of 1

PLAN & ELEVATION

Inner radius of 2

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RECIPROCAL FRAME

PLAN & ELEVATION

Inner radius of 3

PLAN & ELEVATION

Inner raidus of 4

WOOD

A truss is composed of triangles because of the structural stability of that shape. A triangle is the simplest geometric fig-ure that will not change shape, or angles, when the lengths of the sides are fixed. In comparison, both the angles and the lengths of a square must be fixed for it to retain its shape.

The depth of a truss, or the height between the upper and lower chords, is what creates an efficient structural form. For a given span length, a deeper truss will require less material in the chords and greater material in the verticals and diagonals. An optimum depth of the truss will maximize the efficiency.

TRUSSES

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TRUSSES

FLAT HOWE FLAT PRATT

FLAT WARREN LOW SLOPING

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TRUSSES

CANTILEVERED MANSARD DOUBLE CANTILEVERED WITH PARAPET

TOP HUNG FLAT SLOPING PARALLEL CORD

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TRUSSES

TRI BEARING DOUBLE CANTILEVER

DUAL SLOPE CLERESTORY

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TRUSSES

POLYNESIAN GAMBREL

kINGPOST QUEEN POST (FAN)

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TRUSSES

FINk HOWE

FAN MODIFIED QUEEN

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TRUSSES

DOUBLE FINk DOUBLE HOWE

MODIFIED FAN TRIPLE FINk

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TRUSSES

HOWE SCISSORS DOUBLE HOWE SCISSORS

H3201 H2202

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TRUSSES

M32 MONO MONO SCISSORS

WOOD

In researching wood products and byproducts, we researched engineered wood as a possible material type. Engineered wood is also known as composite wood, man-made-wood or manufactured wood. Products of engineered wood include a range of derivative wood products which are manufactured by binding together the strands, particles, fibers, or veneers of woods, together with adhesives, to form these composite materials.

Engineered woods offer a wide variety of uses, dimensions, and applications. As a result, engineered woods have revoluntionzed the wood industry.

ENGINEERED WOOD

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Laminated veneer lumber (LVL) is an engineered wood product that uses multiple layers of thin wood assembled with various adhesives. It offers several advantages over typical milled lumber: it is stronger, straighter, and a lot more uniform. It is much less likely than conventional lumber to warp, twist, bow, or shrink due to its composite nature. Produced in a factory under controlled specifications, LVL products allow customers to reduce the on-site labor. It is similar in appearance to plywood without cross bands, and is typically rated by the manufacturer for elastic modulus and allowable bending stress. Common elastic moduli are 1.8, 1.9, and 2.0 million psi, and common allowable bending stress values are at 2800 and 3000 psi.

Laminated Veneer Lumber products are typically used for headers, beams, rim

ENGINEERED WOOD

board, and edge-forming material. The I-Joist is a product of LVL. These joists work similar to solid woods, yet provide a stronger support system while using less material. These joists are similarly installed as solid wood products.

LAMINATED VENEER LUMBER

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Parallam is made from nearly all of the wood on the log using veneer strands, which are aligned parallel for maximum strength. The end product is a rectangular beam; that which is longer, thicker, and stronger than the conventional solid-sawn lumber. Similar to Laminated Veneer Lumber, Parallam woods are often used as beams, headers, columns, and posts, among others uses.

ENGINEERED WOOD

PARALLAM

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Glued laminated timber, also known as gluelam or glulam, is a type of structural timber product composed of several layers of dimensioned lumber glued together. By laminating several smaller pieces of wood, a single large, strong, structural member can be manufactured from smaller lumber. These structural members are usually used as vertical columns or horizontal beams, often in curved, arching shapes.

Glued laminated timber, like other engineered wood products, represent anefficient use of available timber. With an increased demand for lumber worldwide, the amount of solid timber available has steadily declined. Glulam structural members thus make use of smaller and less desirable dimensions of timber, yet are engineered to be stronger than similarly sized members comprised of solid wood.

ENGINEERED WOOD

GLULAM SHEFFIELD WINTER GARDENS

Sheffield, England

The building has background frost protection to minimum of 4 degrees Celsius and it is one of the largest Glulam buildings in the UK. The wood used is Larch, a durable timber which will turn a light silvery grey color over time. The larch, which derived from sustainable forests, requires no preservatives or coatings. This reduces the use of solvents and also avoids the use of chemicals that could kill the plants inside.

As seen on the images above, two glulam beams are used to complete the entire spand of the structure. Not only do they provide the structural support, but they are aldo incorporated into the design.

WOOD

WOODWORkING + JOINERYWoodworking involves joining together pieces of wood to create furniture, structures, architectural details, toys, and other items. Some wood joints employ fasteners, bindings, or adhesives, while others use only wood elements. The character-istics of wooden joints, strength, flexibility, toughness, etc., derive from the properties of the joining materials and from how they are used in the joints. Therefore, different joinery techniques are used to meet differing requirements

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Woodworking involves joining together pieces of wood to create furniture, structures, architectural details, toys, and other items. Some wood joints employ fasteners, bindings, or adhesives, while others use only wood elements. The characteristics of wooden joints, strength, flexibility, toughness, etc., derive from the properties of the joining materials and from how they are used in the joints. Therefore, different joinery techniques are used to meet differing requirements

Many traditional wood joinery techniques use the distinctive material properties of wood, often without resorting to mechanical fasteners or adhesives. Many wood joinery techniques either depend upon or compensate for the fact that wood is anisotropic: its material properties are different along different dimensions. Wood is stronger when stressed along the grain (longitudinally) than it is when stressed across the grain (radially and tangentially). Wood also expands and contracts in

WOODWORkING

response to humidity, usually much less so longitudinally than in the radial and tangential directions.

Japanese and Chinese craftsman have mastered and have led the usage of woodworking techniques; whether it be used to make furniture or for architecture. Both cultures have woodworking traditions that include hundreds of types of joints, many of which do not use glue or nails to hold in place.

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Joinery technique in which two members are cut to the appropriate length and are joined by simply butting them together. Reinforcements must be used, such as dowels or nails, even so, it is the weakest of all the joints.

The end of the first member, called the tenon, is usually narrowed with respect to a hole of the second piece. The first member is inserted into the hole of the second member, called the mortise. The joint may be glued, pinned, or wedged to lock it in place.

A slot or trench cut into the surface of the first member to match the end of the other. A dado is cut across, or perpendicular to, the grain and is thus differentiated from a groove which is cut with, or parallel to, the grain.

A mortice is cut on each member, each located the correct distance from the face of the joint in both members. A biscuit is then inserted with some glue and the members brought together, aligned and clamped. The biscuit absorbs some moisture from the glue and swells up in the mortice, creating a tightly fitting joint.

Material is removed from each of the members so resulting joint is the thickness of the thickest member. Most commonly in half lap joints, the members are of the same thickness and half the thickness of each is removed

WOODWORkING

BUTT JOINT HALF LAP JOINT DADO JOINT MORTISE & TENON JOINT BISCUIT JOINT

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Similar to a mortise and tenon; a tenon is narrowed on the end of one member and a mortise is cut into the other to accept it. The difference is that the tenon and the mortise are cut to the full width of the tenon member.

Consists of a series of pins cut to extend from the end of one board, interlocking with a series of tails cut into the end of the second board. The pins and tails usually have a trapezoidal shape, allowing the dovetail to be great in tensile strength. Once glued, a wooden dovetail joint requires no mechanical fasteners.

Similar to a Dado and a Mortice and Tenon joints. Groves are cut precisely on both members in order to interlock or slide together. The milled corner joint creates a corner with no end grain visible. One of the stronger joints.

Consists of a recess or groove cut into the edge of one member. The position of the rabbet cut depends on where someone wants the half-section of grained end to appear. With this joint, the grained end of one member is completely hidden.

Joint made by beveling each of two parts to be joined, usually at a 45° angle, to form a corner of a certain angle. A mitered joint may be reinforeced with a spline, which works similar to a biscuit in a biscuit joint.

WOODWORkING

MILLED CORNER JOINTRABBET JOINTMITER JOINT BRIDLE JOINT DOVETAIL JOINT

WOOD

ARCHITECT’S + WOODIn order to understand the limitations of wood, we researched specific architect’s projects in wood including Shigeru Ban, Tado Ando, and Kengo Kuma.

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TADAO ANDO

Seville, Spain

Japan presented at Expo 1992, a pavillion considered the largest wooden building in the world. It was a proposed four-storey building with wooden beams and columns. On the outside Iroko wood, from Africa, was used, while the interior is combined with Canadian fir ceilings covered with teflon and steel. Visitors would come into the second floor crossing a bridge, intended to symbolize the transit between the bank of Japan to the traditional bank of the modern era. From the top floor visitors descend through several exhibition halls.

Ando wasnted to highlight the term "kinari" (Nature in origin), as a beginning and the source of the Japanese culture. It was represented as a reproduction of the Azuchi Castle, when Japan made its first contact with European civilization.

JAPAN PAVILION EXPO ‘92

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Mikata, Hyogo, Japan

Isolated in a solitary position in the heart of the Mikata-gun forest, the Museum of Wood was built to celebrate the National Tree Festival.

The museum is a declared homage to the huge task of reconstruction of the forest resources of which Japan is now justifiably proud, and the fact that it is constructed almost entirely out of wood demonstrates the Japanese veneration for this product of nature that underlies the country's traditional concept of what architecture is.

Built of wood with a steel frame and reinforced concrete, the museaum features a ring-shaped exhibit hall with a 46 meter outer diameter and a 22 meter void within. Locally milled Hyogo cedar was used for the posts and beams. The enormous

TADAO ANDO

MUSEUM OF WOOD

laminated wood columns, which rise to a height of 16 meters, are arranged in a manner that recalls the forest.

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kENGO kUMA

Beijing, China

The purpose of this project was to re-discover and re-express the true essence of Japanese architecture through bamboo as both a structural and non-structual element. The use of bamboo was based on the fact that bamboo, as a piece of raw material, denies to be processed compared to other wood products.

In contrast to that, however, bamboo is used in a manner of original form. Therefore, bamboo is a material and a product at the same time. The project talks about disposition of the material (particles) rather than processing of the material that creates a piece of architecture. It is by coincidence that the particles of bamboo are positioned with some order in this case. These particles can easily retrieve their true essence once the order is scattered around as in a natural environment.

GREAT (BAMBOO) WALL

“You could say that my aim is 'to recover the place, the place is a result of nature and time, this is the most important aspect. I think my architecture is some kind of frame of nature with it we can experience nature

more deeply and more intimately. Transparency is a characteristic of japanese architecture, I try to use light.” ---Kengo Kuma

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Yusuhara, Takaoka, Kochi Prefecture, Japan

The town of Yusuhara, known for its urban development using “Japanese Cedar”, has a new starting point for its community with the “Kino-machi Hall” (Town Hall), the largest scaled “Wooden” town hall in Japan.

Local Japanese cedar was used fully to the regulations, which made possible to create a double lattice girder structure with an 18 meter long span. While making it possible to visualize how cedar structural parts sustain the structure, as seen in the images, this building aims to build an architecture capable of making people reconfirm the excellence of Japanese wooden structures.

YUSUHARA TOWN HALL

kENGO kUMA

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SHIGERU BAN

Nagata-ku, Kobe, Japan

This community center was built by church volunteers whose house of worship was destroyed by Kobe earthquake in 1995. Materials were donated by a number of companies, and construction was completed in only five weeks by the 160 volunteers.

The plan(10 x 15m) is enclosed within a skin of corrugated, polycarbonate sheeting. Within this, 58 paper tubes (325mm in diameter, 14.8mm thick, and 5m high), were placed in an elliptical pattern. The eclipse is based on those in Bernini’s church designs, and the space between the eclipse and the outer edge of rectangular-shaped site formed a corridor and provided lateral support. At the entrance to the eclipse, the spacing of the paper tubes was widened, and the facade fully glazed to

PAPER CHURCH

form a continuous, unified space between the interior and exterior.

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Paris, France

The temporary structure is conceived as one whole continuous space. The different zones are created by partial partitioning formed by tall shelving units. The space is sub-divided into successive areas: reception hall, conference room, work space, rest zone and model workshop.

The whole structure, vault and base, is covered by a system of external membrane in PTFE (Poly Tetra Fluoro Ethylene) in strict accordance with current fire regulations that provides the water-proofing. The two lateral facades and gables are in timber structure and infill panels.

The temporary structure is a tubular space of 34.5 meters in length and 4.4 meters

in width. The circular vault space is entirely covered in its length by a waterproof membrane and panel system that is supported on a system of cylindrical ribs. These are made of 29 semi-circular arches, equal in length, and a network of transversal wind-bracing elements. The arches are at 1.2 meter intervals. The ribs are made of paper tubes, inside 120 mm diameter, 760mm external diameter.

PAPER TEMPORARY STUDIO

SHIGERU BAN

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"It is a very interesting contrast, the Roman stone bridge and the paper bridge. Paper too can be perma-nent, can be strong and lasting. We need to get rid of these prejudices," ---Ban

Nimes, France

Placed over the Gardon River in southern France, half a mile from the Pont du Gard, it reaches over the water to a sandy islet mid-river. Designed by Architect Shigeru Ban, two dozen French architecture students and three from Japan built the bridge as a month-long project.

The cardboard-tube bridge was load tested with balloons filled with 1.5 tonnes of water, calculated to be strong enough to carry 20 people at a time. Weighing at 7.5 tonnes, the bridge is made from 281 cardboard tubes, each 11.5 centimeters (four inches) across and 11.9 millimeters thick. The steps are made of recycled paper and plastic and the foundations were wooden boxes packed with sand.

SHIGERU BAN

PAPER BRIDGE

The bridge was opened to the public for six weeks, which then was dismantled for the rainy season.

WOOD

DESIGNS & TRIALSStarting with miniature models, we experimented with basic reciprocal frame structures, making woodworking joints and began to work on a larger scale. Using information gathered from the study of trusses, previous experiments with different types of materials, and lessons from failures, we began to construct the first model of Shigeru Ban’s paper bridge.

This chapter shows the progression from miniature preceding experiments through the final model.

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MINIATURE TRIALS

HOWE SCISSORS DOUBLE HOWE SCISSORS

TRUSS STUDY

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trials

JOINT WORk

BRIDGE STUDY

DESIGN & TRIALS

Materials used: 63 cardboard mailing tubes, 25 pvc connections, and nearly 150 nuts and bolts.

The following images show the types of connections used. PVC was glued together with Wings-n-Things glue, containing Cyanoacrylate. Each tube had a bolt on each

of their sides, with exception of one side which had two on each side for a stronger joint.

DESIGN & TRIALS

Zip-ties were added to strengthen the join connection.

DESIGN & TRIALS

Section twists as seen on following images, this twist is made of 16 triangular sections.