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Wood trusses are widely used in single- and multi-family residential, institutional, agricultural and commercial construction. Their high strength-to-weight ratios permit long spans, offering greater flexibility in floor plan layouts. They can be designed in almost any shape or size, restricted only by manufacturing capabilities, shipping limitations and handling considerations.

Strength: Trusses provide a strong and efficient wood system specifically engineered for each application

Economy: Through efficient use of wood and by providing a system that is quickly installed in the field, wood trusses provide an economical framing solution

Versatility: Complex shapes and unusual designs are easily accommodated using wood trusses. The versatility of wood trusses makes it an excellent roof framing system in hybrid construction where wood trusses are commonly used with steel, concrete or masonry wall systems.

Environmental: Wood, the only renewable building material, has numerous environmental advantages. Wood trusses enhance wood s environmental advantages by optimizing wood use for each specific application.

. Truss shapes have almost unlimited variety, thus allowing for distinctive roof shapes. 2. Many restaurant chains choose to expose their corporate identity in the roof design of their buildings. 3. Metal plate connected trusses are used to create arches of all types. 4. Wood trusses used in specialized applications such as agricultural and commercial buildings provide spans exceeding 25 m. 5. As a testament to their strength, wood trusses are used in concrete formwork, scaffolding and falsework for industrial projects. 6. The open web configuration of roof and floor trusses allows easy placement of plumbing, electrical, mechanical and sanitary services.

COMPOSITE TRUSSES Trusses are efficient structural systems, since the members experience essential ly axial forces and hence the materials are fully utilized. Steel as a structural materia l is equally strong both in tension and compression and hence steel trusses are more efficien t. They tend to be economical to support loads over larger span lengths. However, the me mbers in the compression chord of the simply supported steel truss (top chord) may pre maturely buckle before the stresses reach the material strength. In this context the conc rete slab acting in composite with the truss compression chord becomes useful (Fig. 6). A reinforced concrete or composite deck floor is required in any case in building and other structures to provide a flat surface. Using it as a part of the compression memb er in truss

system could be an economical proposition. Concrete has a lower strength compare d with steel and hence requires larger cross section to sustain a given compression. Consequently, the concrete floor slab used as a part of the compression chord of the truss is less vulnerable to buckling failure. Further, concrete can more economically carry compression, whereas it is very weak in tension. In a composite truss system the relative merits of steel and concrete as construction materials are fully exploited. It i s one of the most economical systems in longer span flooring construction. Thus composite tru ss systems are structurally efficient and economical.

STEEL TRUSSES Advantages of light gauge steel trusses Steel Trusses Pre-engineered steel truss components are precision designed by computer and shop drawings are provided making the review process easy. Steel trusses may be designed for long spans that eliminate intermediate bea ring walls. Larger open spaces and increased design flexibility result. Most steel trusses are built in quality controlled manufacturing plants and are shipped to your job site completely assembled. Because of its strength, steel can mean fewer framing members. Savings in ma terials and labor are realized. Light gauge steel trusses weigh less than wood trusses. Shipping costs are r educed. Installation and handling are easier. Steel is safer. Its non-combustible qualities and strength better resist fir es, earthquakes and hurricanes. Steel trusses are fabricated in supervised, worker-friendly plants where hig h production is achieved, lowering the final cost. Steel is free from problems associated with rot and termites and it does not warp, shrink or swell like wood products. Steel trusses are delivered to your jobsite ready for erection or are erecte d at your site by the truss manufacturing personnel. Steel trusses provide long-term quality performance. Steel has the highest recycling rate of all materials. Steel trusses have the design flexibility to accomidate almost any roof and ceiling profile you can imagine. And steel makes a great substrate for any roofi ng material.

Cast iron has good compressive strength but relatively poor tensile strength. Because of the impurities in cast iron t is a strong material in compression, . As a result when it failed it did so g. It can be subject to blemishes and entury ironwork contractor: "It is not gth, but the judicious proportions and and its crystalline structure, although i it is weak in tension and is very brittle in an explosive manner with little warnin flaws, hence the warning made by a 19th c the masses of metal that constitute stren forms of the casting".

The casting process enables the production of complex shapes. Because it is produced by casting, ie. made by pouring into a mould, it is well suited to the production of intricate shapes, both structural and decorative. Fo r structural use, cast iron was best suited to elements where the predominant lo ad caused compression; and so was most commonly used for columns. Casting iron Wrought iron has better tensile strength than cast iron and is more ductile. Wrought iron has better properties than cast iron for structural use. Because of its low carbon content wrought iron is ductile, 'tough' and has good resistance to corrosion. It is more fibrous in texture, highly ductile, and is strong in b oth tension and compression. The Eiffel tower is constructed from puddled iron, a form of wrought iron

eHow Home & Garden Landscaping & Outdoor Building Fences & Walls Difference Between Steel & Wrought Iron Difference Between Steel & Wrought Iron By William Norman, eHow Contributor Share Print this article Wrought iron and steel may seem similar on the surface, but these two metal allo ys possess different raw materials, properties, and industrial and decorative ap plications. Other People Are Reading Aluminum Fence Vs. Wrought Iron Properties of Iron & Steel Definitions

While people sometimes use the terms wrought iron and steel interchangeable, wrought iron combines pure iron ore with a glassy material called iron silicate , while steel also contains carbon, according to Production Both metals go through a firing process to give them strength. Wrought i ron forms during charcoal firing or as a byproduct of cast iron production, acco rding to the Real Wrought Iron Company. Steel forging adds and removes various c ompounds and oxides to create the final alloy. Sponsored Links Quality chemical etching Prototype-production, ISO certified Fotofab has fast quotes & delive ry. Strength Steel possesses greater tensile strength than wrought iron. Steel may sh ow more vulnerability to corrosion than wrought iron, with the exception of stai nless steel. Telltale Differences Wrought iron and mild steel may bear a close resemblance at first glance , but close inspection by an expert often reveals rougher workmanship and more c orrosion in the steel product.

Carbon fiber is a super strong material that's also extremely lightweight. Engin eers and designers love it because it's five times as strong as steel, two times as stiff, yet weighs about two-thirds less. Carbon fiber is basically very thin strands of carbon -- even thinner than human hair.

acrylonitrile butadiene styrene(ABS)

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