BUILDING TECH 5

BT5

Non-Conventional System of Construction

• Built from materials that do not conform to the usual definition

• The use of reinforced concrete columns to constitute the walls and structure of the house or a building

Standard Houses Walls Materials

Brick or stone

Standard Houses Roof Materials

Slate or Tiles

• Metal Frame

• Concrete Frame

• Timber frame

• Concrete Panel Construction

• Sips Structural Insulation Panels

Over the year non-traditional housing has taken the form of:

Wood

• It is the best loved of all the materials that we use for building

• It delights the eye with its endlessly varied colors and grain patterns

• It invites the hand to feel its subtle warmth and varied texture

Engineered Wood Boards

• Are generally made from the same hardwoods and softwoods used to manufacture lumber, but mixed with additives like adhesives

• Type of wood often utilizes waste wood from sawmills, and are treated through chemical or heat processes to produce wood

Engineered Wood

• Also called mass timber, composite wood, man-made wood, or manufactured board

• Includes a range of derivative wood products which are manufactured by binding or fixing the strands, particles, fibers, or veneers or boards of wood, together with adhesives, or other methods of fixation to form a composite material

application-specific performance

Because engineered wood is man-made, it can be designed to meet _________ requirements.

versatile

Engineered wood products areand available in a wide variety of thicknesses, sizes, grades, and exposure durability classifications.

designed and manufactured

Engineered wood products are _________ to maximize the natural strength and stiffness characteristics of wood

greater structural strength

The products are very stable, and some offer _________ than typical wood building materials.

strength and stiffness

Glued laminated timber (glulam) has greater _________ than comparable dimensional lumber and, pound for pound, is stronger than steel.

easy to work

Engineered wood panels are _________ with using ordinary tools and basic skills. They can be cut, drilled, routed, jointed, glued, and fastened.

efficient use of wood

Engineered wood products make more _________. They can be made from small pieces of wood, wood that has defects, or underutilized species.

high strength-to-weight ratios

Woodend trusses are competitive in many roof and floor applications, and their _________ permit long spans offering flexibility in floor layouts

require more primary energy

They _________ for their manufacture than solid lumber

toxic

The adhesives used in some products may be _________.

formaldehyde

A concern with some resins is the release of _________ in the finished product

toxic compounds

Cutting and otherwise working with some products can expose workers to _________.

humidity-induced warping

Some engineered wood products may be weaker and more prone to _________ than equivalent solid woods.

not appropriate for outdoor use

Most particle and fiber-based boards are _________ because they readily soak up water.

Types of Engineered Wood

• Structural Glued Lumber/ Structural Composite Lumber

• Machine Stress-rated Lumber (MSR)

• Glue Laminated Lumber (Glulam)

• Alternative Building Boards

Types of Alternative Building Boards

• Oriented Strand Boards (OSL)

• Parallel Strand Boards (PSL)

• Particle Boards (PB)

• Medium Density Fiber (MDF)

• Laminated Veneer Lumber (LVL)

Structural Composite Lumber (SCL) and Glue Laminated Lumber (GLULAM)

Recognized as rectangular shaped products that have strength, stiffness, and consistency resulting from wood fiber orientation and strict manufacturing process control

Structural Composite Lumber (SCL) Products

Grown in popularity because of the ability to manufacture long length and large cross-sectional dimensions with consistency.

Structural Composite Lumber (SCL) billets

The grain of each layer of veneer or flakes runs primarily in the same direction.

same direction

The grain of each layer of SCL billet’s veneer or flakes runs primarily in the _________.

Structural Composite Lumber (SCL) Applications

• Rafters

• Headers

• Beams

• Joists

• Studs

• Columns

• I-joist flange

Structural Composite Lumber (SCL) Sizing

¾” to 3-1/2” thick, depths and lengths to match the end use

Types of Structural Composite Lumber: Log-Processing Methods

• Stranding

• Rotary Peeling

Log Processing: Strand Products

• Laminated Veneer Lumber (LVL)

• Parallel Strand Lumber (PSL)

Log Processing: Rotary Peel Products

• Laminated Strand Lumber (LSL)

• Oriented Strand Lumber (OSL)

Laminated Strand Lumber (LSL) and Oriented Strand Lumber (OSL)

Used primarily as lumber substitute and as flanges in I-joist

Laminated Strand Lumber (LSL)

• Made form flaked wood strands that have a length-to-thickness ratio of approximately 150

• Combined with adhesive, the strands are oriented and formed into a large mat or billet and pressed

• Weakest engineered materials, but usually expensive and the best value if it meets structural demands

150

Approximate length-to-thickness ratio of Laminated Strand Lumber (LSL)

Laminated Strand Lumber (LSL) Applications

Variety of applications from studs to millwork components

Oriented Strand Lumber (OSL)

• Made from flaked wood stands. The strand geometry results in length-to-thickness ratio of approximately 75

• Combined with an adhesive, the strands are oriented and formed into a large mat or billet and pressed.

75

Approximate length-to-thickness ratio of Oriented Strand Lumber (OSL)

Parallel Strand Lumber (PSL) and Laminated Veneer Lumber (LVL)

Used primarily as lumber or heavy timber substitutes, and as flanges in I-joist.

LVL

_______(acronym) uses full-size veneer sheet, which can range from one-tenth to one-sixth of an inch thick

PSL

_______(acronym) uses veneer which is too narrow for plywood

Parallel Strand Lumber (PSL)

• Manufactured from veneers clipped into long strands laid in parallel formation and bonded together with an adhesive to form finished structural section

• The length-to-thickness ratio of strands is around 300

• Best combination of strength and stiffness

• Can be pressure treated

300

Approximate length-to-thickness ratio of Parallel Strand Lumber (PSL)

Parallel Strand Lumber (PSL) Applications

• Used for beam and header where high-bending strength is needed.

• Frequently used as load-bearing columns

Laminated Veneer Lumber (LVL)

• Widely used structural composite lumber product

• Produced by bonding thin wood veneers together in a large billet so that the grain of all veneers is parallel to the long direction.

• Available in lengths far beyond conventional lumber lengths

• Not meant to be exposed to view or to weather

Laminated Veneer Lumber (LVL) Applications

Include headers and beams, hip and valley rafters, scaffold planking, and the flange material for prefabricated wood I-joists

Glue Laminated Timber (Glulam)

• Produced by laminating plants by gluing together layers of sawn lumber to form large cross-sectional timbers that retain the traditional look of wood

• Stacked, finger-jointed layers of standard lumber

• The only heavy structural framing member that can be manufactured in curves or arches

• Desirable for their strength characteristics and appearance

Machine Stress-rated Lumber (MSR)

• Softwood dimension lumber that had its strength predicted by mechanical means rather than by relying on visual indicators

• Has been used for producing engineered wood products such as roof trusses

• Grading is based on established relationship between stiffness of lumber and bending strength

Grades of MSR lumber

assigned “f-E“ values;

“f“ value : predicted strength in pounds per square inch (psi)

“E“ value: average stiffness measured in millions of pounds per square inch (106 psi)

“f“ value

predicted strength in pounds per square inch (psi)

“E“ value

average stiffness measured in millions of pounds per square inch (106 psi)

Medium Density Fiber (MDF)

• Engineered wood product formed by breaking down softwood into wood fibers, combining it with wax and resin, forming panels by applying high temperature and pressure

• It is denser than normal particle board

• Known as Custom Wood or Craft Wood

600 to 800 kg/m³

Typical density of MDF

Custom Wood or Craft Wood

Other name for MDF

Medium Density Fiber (MDF) Advantages

• Some varieties are less expensive than many natural woods

• Isotropic (no grain), so no tendency to split

• Consistent in strength and size

Medium Density Fiber (MDF) Disadvantages

• Heavier (the resins are heavy)

• Swells and breaks when waterlogged

• Warps or expands if not sealed

• Contains urea-formaldehyde which may cause eye and lung irritation when cutting and sanding

• Dulls blade more quickly

Green

Moisture-resistant MDF color

Red

Fire-retardant MDF color

Ultralight

Lighter densities of fiberboard are commonly marketed as _____

Particle Board (PB)

• Known as chipboard or low-density fiberboard

• Engineered wood product manufactured from wood chips and a synthetic resin or other

Wood fasteners

• Have always been the weak link in wood construction

• Generally based on metal devices, it is usually impossible to insert enough nails, screws, or bolts in a connection to develop the full strength

Nails

• Sharp-pointed metal pins that are driven into wood with a hammer or a mechanical nail gun

• Ordinarily furnished bright, plain, uncoated steel

Wood Screws and Lag Screws

Spiral threaded fasteners installed by turning action whereby the threads draw the screw tightly into the material being fastened

Self-drilling Wood Screws

• Do not required pre-drilled pilot holes and can be installed more quickly with power screwdrivers

• Used for attaching subflooring to floor framing

Specialty Screws

• Comes in an endless variety of styles

• Alternate driver shapes engage and hold screws more reliably and can transmit greater torque than traditional slotted or Phillips drivers

• Wider steeper thread patterns improve screw-holding strength and allow faster driving.

Alternate driver shapes

Engage and hold screws more reliably and can transmit greater torque than traditional slotted or Phillips drivers

Wider steeper thread patterns

Improve screw-holding strength and allow faster driving

Bolts

• Used mainly for structural connections in heavy timber framing, and less frequently, in wood light framing for fastening ledgers, beams, or other heavy applications

• Range in diameter from 3/8 to 1 in (10 to 25 mm) in almost any desired length

Timber Connectors (Split-ring)

• Used in conjunction with a bolt and is inserted in matching circular grooves in the mating pieces of wood

• Provides greater capacity by spreading load across much greater area of wood than can be done with a bolt alone

Toothed Plates

• Are used in factory-produced lightweight roof and floor trusses

• Are inserted into the wood with hydraulic presses, pneumatic presses, or mechanical rollers and acts as metal splice plates.

Sheet Metal and Metal plate Framing Devices

• Manufactured for strengthening common connections in wood framing

• Most frequently used is the joist hanger

Trusses

• Manufactured in small, highly efficient plants

• Based on 2 × 4s and 2 × 6s joined with toothed plate connectors

Wood I-Joists

• Used for framing both roods and floors

• Lighter in weight than corresponding solid members, lack crooks and bows, are more dimensionally stabile, and are available in lengths up to 40 feet (12.2 m)

Concrete

• Universal material of construction

• According to the World Business Council for Sustainable Development, it is the most widely used material on earth

• Is the only major structural material commonly manufactured on site, it has no form of its own, and it has no useful tensile strength

Hadrian’s Villa

A large palace built near Rome between A.D. 125 and 135, used unreinforced concrete extensively for structures such as this dome

Cast-in- Place

• A concreting technique which is undertaken ‘in situ’ or at the site utilizing temporary formworks

• Also referred to as “poured-in-place”

• This is the preferred choice for foundations, slabs, columns, beams, walls, roofs, etc.

Cast-in- Place Advantages

• Most commonly used

• Level of Strength

• Versatile

• High degree of insulation

• Provides thermal insulation

• Mold, rot, mildew and insect resistance

• Sound-blocking ability

• Cost savings

Cast-in- Place Disadvantages

• Labor intensive

• Length of time for curing

• Removing formworks and formwork supports/ scaffolds

• Consistency of concrete may vary

• Not cost-effective building technology for bigger projects

Cast-in- Place Installations

• Placement of formworks

• Provision of Reinforcement bars

• Pouring concrete

Compressive Strength and Stiffness

Important Criteria of Cast-in Place for structural columns, beams, and slabs

Surface Smoothness and Abrasion Resistance

Important Criteria of Cast-in Place for pavings and floor slabs

High Degree of Weather Resistance

Important Criteria of Cast-in Place for pavings and exterior concrete walls

Class AA Concrete Mixture

1: 1-1/2: 3

Class A Concrete Mixture

1: 2: 4

Class B Concrete Mixture

1: 2-1/2:5

Class C Concrete Mixture

1: 3: 6

Class A Mortar Mixture

1: 2

Class B Mortar Mixture

1: 3

Class C Mortar Mixture

1: 4

Class D Mortar Mixture

1: 5

CLASS “AA” Concrete Mix Application

CONCRETE UNDER WATER, RETAINING WALLS

CLASS “A” Concrete Mix Application

FOOTINGS, COLUMNS BEAMS, R.C. SLABS

CLASS “B” Concrete Mix Application

SLAB ON FILL, NON BEARING WALLS

CLASS “C” Concrete Mix Application

CONCRETE PLANT BOXES, ETC

READY MIX CONCRETE

Batched in a stationary plant then hauled to the site

1 1/2 hours

Maximum duration of time for concrete to be discharge from the truck mixer after the water is poured to the batch

Admixture

Material other than water, aggregates, lime or cement, used as an ingredient of concrete or mortar, and added to the batch immediately before or during its mixture.

Two main tests to be done on concrete

• SLUMP Test

• COMPRESSION Test

SLUMP test

• Shows the WORKABILITY of concrete

• Workability measures how easy the concrete is to place, handle and compact

7.5 cm. (.075) 3”

ALLOWABLE DEFLECTION ‘X’ ON:

• BEAMS AND COLUMNS

• CANAL LINING