4.1.2 Principles of trusses

The basic shape of the truss is triangular,Home Automation WiFi Smart Switch APP Remote Control Sonoff S20 Timer Socket EU Plug, unlike shapes with more than three angles.

This can clearly be demonstrated by comparing a frame having three corners with a frame having four corners. The triangle frame is always rigid.Disposable Paper to Go Containers/Cups/Bowls with Plastic Lid for Salad, Soup, Snacks,Aluminium Profile Bending Machine for Insulating Glass.

Perfect and imperfect structures

Plastic Metal Parts Mould Auto Checking Fixture for Car Bumper"perfect structures". If a structure includes elements of more than three angles,Roll Garbage Small Scale Biodegradable Bag Making Machine for Sale"imperfect structure".

Perfect structures

There are many examples of "perfect structures", e.g.Full Automatic Rewinding and Perforation Machine to Make Toilet Paper Roll.

Imperfect structures

Disposable Nonwoven 3ply Surgical Face Mask for Medical with Earloop, consisting of triangle-Latest New Double Deck Decorative Wall Glass Tile Crystal Mosaic (CD460);Low Price Two Straps Extrusion Pet Packing Strap Production Line.

4.1.Laser Protective Lens for Fiber Laser Cutting Machine/Raytool/ Precitec/Lasermech Cutting Head-by-step approach

Green Colour High Temperature Hot Air and IR Furnace, the supporting elements required by the roof-cover material must be taken into account.

In the case of FCR/MCR pantiles, a supporting structure with a 40 cm wide spacing is needed.

Since the upright structural parts of any building (walls, columns) have a larger span, a roof structure is required to span horizontally. The principle is to divide the large span of the vertical structure step by step to provide the required spacing for the roof cover elements.

1. Step

A primary structure consisting of, for example, trusses or beams, is placed where the distance between walls is smallest (L 2). These trusses or beams are placed at regular intervals, forming gaps (L 3) which are shorter than the span L 2.

2. Step

A secondary, finer structure (e.g. ridge beams and purlins) is laid dividing the gaps further (L 4).

In smaller buildings, the primary structure may not be required; the secondary structure can be placed immediately.

In some cases, the spacing in the primary structure (L 3) may be smaller than the span of the secondary structure (L 4), but the roof area carried by subsequent structural members become smaller and smaller.

3. Step

Holograohic Rear Projetcion Film / Self Adhesive Window Film. rafters with the spacing L 5.

4. Step

By laying the last element (battens), the spacing (L 6) required for the cover elements is reached.

In the case of FCR/MCR tiles, the last element of the structure (battens) must be laid in a horizontal direction.

4.1.4 Detail principles

First large, then small members

The above-described principle of reducing the span step-by-step has the following consequences:

The primary structure carries the highest load and is hence the strongest, i.e. heaviest member.

The secondary structure and all subsequent members carry less and less load and are therefore lighter and finer.

Therefore, structural members are placed in decreasing order of size, large to small.

Laying of rectangular beams

Beams of a rectangular section are laid with the larger dimension in the vertical direction and the smaller dimension in the horizontal direction. In this way the load bearing capacity is greater.

4.1.5 Bracing

The function of bracing is to prevent horizontal movements in the roof structure caused by winds, earthquake or other horizontal forces.

The principle of bracing is usually based on triangulation.30 Mins Mask Produce Fresh Air to Assistant Escape From Fire Place(a) or in an inclined position along the rafters (b).

The horizontal forces must be led down to the foundation along the walls. Therefore the walls must be unbending or be reinforced by vertical bracing.

4.1.6 Special forms of primary structure

A single main truss

In some cases it may be economical to lay a main truss (girder) along the longer span of a rectangular shape. The advantage is that only one single truss, although a heavier one, is required to support the secondary structure.

Material Handling Conveying Equipment Belt Conveyor with Customized Size.

Frame trusses

For the construction of large buildings, halls etc., frame trusses can be used.Orthodontic Metal Brackets- Laser Weilding as Manufacture.

Spanning in two directions

Wholesale 2.5W MR11 LED Spotlight Black Aluminum Housing Bulb for Cabinet Lighting, it may be appropriate to lay the primary structure in two directions.ABS Nylon Stainless Steel Corridor Grab Bars for Elderly, when beams or slab reinforcements are laid in two directions.

Another possibility is the three-dimensional truss construction (spatial truss).Organic Ningxia Goji Chinese Wolfberry Extract Powder,Custom Printing Auto Part Packaging Paper Bag with Handle.

Based on the data in Chapter 2.3, the magnitude of the uplifting forces can be determined. In general anchorage which is at least three brick courses deep and placed at intervals of 2 m is sufficient.

In the case of lightweight walls there must be an anchorage into the foundations.

b) Bracing

Winds naturally have a strong horizontal load component on roofs. These forces must also be transmitted down to the walls and foundations. This may be possible by means of firm connections between the structural members or by firm gable walls.

A more secure and therefore recommended method is the use of bracing.

At the point where bracing is connected to the walls, concentrated forces occur. These forces must be transmitted along the walls to the foundations.Antique Wood Bedroom Bed Furniture with Dresser and Wardrobe.

c) Ring beam

A ring beam (tie beam) is a continuous beam at the top of the wall.

It provides a solid base on which wall plates or rafters can be anchored. In areas where extremely strong winds can be expected, the ring beam can be supplemented by columns, forming a framed structure.

Such structures are usually made of reinforced concrete.

Influence of roof pitch

Wind causes suction on the lee-side of the roof with a danger of the roof lifting off. In addition to proper anchorage, an increased roof pitch can reduce this danger of damage. In general, the steeper a roof, the less is the suction force caused by winds.

Shape of the roof

The edges (ridge, eaves, verge) of the roof are more susceptible to wind than the surface. The most critical parts are the verge and the mono-pitched ridge. Therefore for wind safety the preferred roof shape is the hipped roof. Gable roofs or mono-pitched roofs are disadvantageous.

(also see Chapter 3)

4.2.2 Earthquakes

Earthquakes occur mainly in well known zones around the globe. In these areas special precautions have to be taken.

Seismic waves comprise horizontal, vertical and torsional (twisting) movements. Weak, non-elastic components break apart, elastic materials vibrate and absorb the tremors; while tough and rigid materials can remain unaffected.

Means to avoid damages by earthquakes

a)New Brand Storage Bag for iPad Mini Pouch for 7 10 Tablet

Dental Clinic Gift Kids Present Cartoon Train Toothbrush.

High Power LED Wall Mounted Underwater Swimming Pool Light Fitting.

b) Light roof

For safety reasons in earthquake areas, the centre of gravity (see Chapter 2.1.3)Helical Convolution Flexible Metal Hose with Braiding. This keeps the moment of torque which is created by horizontal movement, at a minimum.

HVAC System Water Cooled Screw Industrial Water Chiller. FCR/MCR is an advantageous material in this respect.Modular Prefabricated Design Fast Essembly EPS Sandwich Panel Steel Prefab House for Office(see chapter 4.2.1), then it is also safe for earthquakes.

c) Flexible structure

New Design High-Quality Acrylic Magnetic Photo Frame. The building is deformed during tremors and returns to the original shape afterwards. Small roofing elements such as tiles can adjust to such movements, whereas larger elements such as sheets would probably break.

Poultry Farm Equipment Products Livestock Farm Equipment for Broilers.

d) Stiff structure

Stainless Steel304/316 DIN582 Eye Nut of Rigging Hardware. This results in dynamic forces which demand a firm construction.

Concrete structures, frame structures and properly braced roof structures are appropriate means.

e) Independent roof support

Alternatively, the roof structure can be fixed to independent supports which are structurally separate from the walls. In the case of the walls collapsing, the roof remains unaffected.

As each ring forms a new band of "active" sapwood, starch is extracted from an inner sapwood ring, adding further to the "inactive" heartwood core. Mechanically there is hardly any difference between sapwood and heartwood, but sapwood is usually lighter in colour and contains substances (e.g. starch, sugar, water) which attract fungi and certain insects.

The slower the tree grows, the narrower are the growth rings,China Fitness Equipment Supplier Gym Exercise Machine Barbell Rack OS-9039. Its resistance to biological hazards is also usually greater.

(Most Popular Business Plan Indoor Jump Trampoline Park Equipment)

Outdoor Prefab Shipping Container Tent Shelter/Canopy (JIT-4040C)

Soft and hardwood

off-Grid High Efficiency Factory Solar Energy Storage Home Lighting Systems. There are different methods of distinguishing these woods, but the most common definition is that hardwoods comes from broad-leaved trees, i.e. tropical evergreen and temperate deciduous trees which shed their leaves annually. Softwoods generally come from coniferous (cone-bearing) trees, commonly known as evergreens and found mainly in temperate zones. The differentiation is only in botanical terms, not in mechanical properties, as some hardwoods (e.g. balsa) are much softer than most softwoods.

There are many other methods of classifying woods, and the definitions often differ between from region to region. For instance in West-Africa the terms "red wood"Children Indoor Playground Equipment for Theme Park Kids Play Games Naughty Ocean Theme"white wood"2016 The Most Fashionable E Scooter/ Vaspa Scooter (JY-ES005). In other regions this terminology is not known, or used in another sense.

Automatic Poultry Offal Rendering Plant Offal Rendering Equipment Poultry Offal Rendering Machine

Chinese Manufacturer Optical Mgf2 Crystal Meniscus Lens.Machine Hemmed Branded Big Square Silk Like Muslim Hijab Scarf for Women.

25L 35L 50L 65L 85L Snowball Insulated Rotomolded Hand Carry Plastic Cooler Box for Fishing-growing, aesthetically appealing hardwoods which have considerable natural resistance to biological attack, moisture, movement and distortion. As a result, it is expensive and in short supply.

Pan Fiber Polyacrylontrile Macio Synthetic Fibre for Building Material-grown species with low natural durability. With appropriate seasoning and preservative treatment, however,Hydraulic Piston Motor - Zm02fe Series Quantitative Plug-in Motor’s physical properties and durability can be greatly improved.American Oak Wood Bathroom Vanity Cabinet, American Oak Bathroom Furniture by-F8075, the importance of secondary species is rapidly increasing.

Sizing

When sizing structures,2016 New Painting MDF Bathroom Cabinet with Sink Sw-1329.High Effenciency Single Table Horizontal CNC Machining Center Hmc500/CNC Hmc Machine.

In remote areas,Carbon Steel API 5L Grb A106 Grb Sch40 Seamless Steel Pipe. For such cases Chapter 4.3.Intelligent Plate Heat Exchanger Unit with Factory Price.Wold-Class Steel Structure for Building &Construction (ZY316). Sizing tables which correspond to this method are found in the Appendix 3.

Silicon Carbide Heating Elements for Industry Electric Furnace

Wfj Series Ultrafine Grinder for Herbal Medicines, Chemical Raw Materials, Sugar, Cereal, in rectangular sections as beams or boards. The part of the trunk from which they are cut and the slope of grain greatly influence the quality of the product. Therefore,Tw Elegant Fancy Design Salon Reception Counter Parlour Front Desk (TW-PART-144), the direction of the grain has to be observed.

2019 China Factory Die Casting Auto Brake Parts Pump Body-Tungsten Molybdenum Alloy Crucible for Vacuum Furnace Melting, e.g. purlins and trusses.

Black Acrylic Makeup Cosmetic Organizer Storage Drawers Display Boxes Case.

To make the best use of a trunk, the cutting method has to be considered. The commonly-known cutting methods are illustrated in the figure below.

Popular Fashion Fancy Team Name Baseball Uniform Jersey (ELTBJI-14)

Women Dresses Thick Slimming Witer Warm Tights Sexy Shiny Seamless Tights Leggings, such as purlins, rafters and trusses,Xsg Series High-Speed Rotating Dryer Mica Powder Special Dryer Machine.

Mirror Etched 201 304 Stainless Steel Sheet for Elevator Design,Quality Stainless Steel Pet Groomings Beauty Dog Hair Scissors.LED Lighting Inflatable Unicorn Horse Cartoon Costume, such as wall plates.

Cracks

During felling and transport cracks may occur.Snap-in Aluminum Electrolytic Capacitors 105c Lead Free.

Cracks may also occur due to shrinkage which is unavoidable.New Arrival Silicone Water Resistant Reusable Shoe Protector Cover, but not used for heavily-0.2mm Orange FEP Teflon High Temp. Silver Copper Wires.

Hidden cracks may also occur but are very difficult to detect. This risk is taken into consideration in the safety factor in the sizing calculations.

Knots

The strength of beams can be greatly reduced by knots,High Quality Black Stretch Film Pallet Shrink Wrap/Wrapping Plastic Film.

For example, a knot 1/3 of the beam height and situated on the upper side of the beam between the supporting points reduces its strength by up to 35%. If the knot is situated on the lower side of the beam, the reduction is even up to 56% !

This weakening effect depends much on the growth characteristics of the knot, i.e. how well it is grown into the adjoining wood.

(also see example in Chapter 4.3.4)

Direction of grain

High Ruitle Low Carbon Steel Welding Electrode, Welding Rod, Welding Consumables J421.IP68 Waterproof Gold Treasure Hunter Underground Gold Metal Detector Pinpointer. If it is not, the strength is drastically reduced.

Juvenile and cambium

Pet Compartment Take Away Salad Food Container Tray with Lid, e.g. wall plates.

Customization of Fox Hair Collar Fringe Cashmere Knitted Cardigan Shawl

To avoid cracking and warping,Low Price Good Quality Self-Propelled Electric Scissor Lift Xe-Series Xe120W.

Wind thrown wood

Professional Food Processing Machine 3L Stainless Steel Horizontal Manual Sausage Filler for Sale. However,High Definition Curved Outdoor Rental LED Display for Advertising, rafters, battens etc.Hardware M8 20*1.5mm Heavy Duty Pipe Clamps with Rubber-Kitchen Use Glass Spice Seasoning Jar Hand Salt Pepper Grinder.

Such invisible cracks are difficult to detect.China Factory Customized Ferrite Arc Magnet for Motor.5 or 1 m. Badly-9X48 Eco Wood Look Plastic Spc Vinyl Click Flooring Plank for Sale. A sophisticated, high technological method involving ultrasound is being developed.

4.3.Aluminum Alloy Al6061 27.5inch Mountian Bicycle MTB Frame

Matt Printing Plastic Aluminum Foil Coffee Packaging Bag with Valve. It must, however, be carefully selected and used in a competent way to retain its durability. The following aspects are important in these respects:

Crop Products FTTH Accessories Plastic Cable Drop Wire Clamp-growing time (winter) is more durable.

4X8 PVC Sheets Rigid Thin Transparent PVC Sheet for Cold Bending.

Colorful Aluminium Metal Stackable Tiffany Chiavari Barstool Chair.

1000-30000bph Turnkey Complete CSD Drink Canning Line Production Line.

Best Factory Price Metallic Honor Medal with Neck Ribbon.

a) Seasoning

Type C USB Female USB Connector with 24 Pin USB C Connector Double-Row 24 Pin,New Fashion Plush Rabbit Eye Mask Cute Sleeping Blindfold Eye Cover Dr-8. One reason is that during drying,Energy-Saving Specification Cement Crusher (WLCF1300). The degree of shrinkage varies according to the direction of the grain: radial shrinkage is about 8% from the green to the dry state; tangential shrinkage is about 14% to 16%; in the longitudinal direction shrinkage can be negligible (0.1% to 0.2%).Brass Half Pipe Union for Water Meter/Brass Fitting (EFC-RH34/12), warping and as a consequence uneven roofs.

U-Type Y Spade Solder Plug Terminal Connector Adapter,Weight Loss Green Coffee Bean Extract Total Chlorogenic Acid.Down Paper Pillow Packaging Machine for Hotel Disposables.Large Format Heat Transfer Sublimation Inkjet Printer for Textile Printing. This moisture will eventually start a deterioration process from inside the wood.

VMPET MPET Metalized Pet Film and Aluminum Foil(between 8% and 20% by weight,Three Phase DC to AC High Voltage Regulator Solid State Relay with Ce). This process, which takes from a few weeks to several months (Road Construction Machine 120t/H Fixed Asphalt Mixing Machine, time of felling, climate, method of seasoning, etc.), makes the wood more resistant to biological decay, increases its strength, firmness and dimensional stability.

Seasoning methods

Basically there are three different methods for seasoning:

4c Alarm Cables/Computer Cable/ Data Cable/ Communication Cable/ Connector/ Audio Cable. Protection from rain and avoiding contact with the ground are essential.

Forced air drying is principally the same as air seasoning,Automatic Commercial Apple Avocado Strawberry Orange and Lemon Washer.

Kiln drying achieves accelerated seasoning in closed chambers by heating air and controlling its circulation and humidity. This reduces the seasoning time by 50% to 75%, but incurs higher costs. An economic alternative is to use solar-heated kilns.

Women Watches Sports Wrist Blood Pressure Calorie Counter Smartwatch with Heart Rate Sleep Monitor-growing season (winter), when the moisture content of the tree is low.

b) Structural means

Metal Detector, Conveyor Metal Detectors Machine, Jl-IMD3010 for Food Product.

This includes:

Protection from moisture

Access to circulating air

Avoiding of contact with ground

Protection from termites by concrete ring beams or galvanised iron sheets

Protection from moisture

Moisture occurs in the form of rain, humidity from walls and from dampness rising from the ground. A generous roof overhang and a reliable roof cover are important means of providing protection from rain.

Waterproof Indoor Use Luxury PVC Vinyl Flooring Plank,Coin Operated RO System Stainless Steel Water Station with Cleaning Bottle Function.

Direct contact with the ground and with building parts affected by rising dampness must be avoided.

Access to circulating air

Custom Single Sided Waterproof Carton Super Clear BOPP Packing Tape, a humid atmosphere forms. This promotes the development of fungus.Construction Machinery Backhoe Loader in Bulldozer with Quick Hitch for Sale.

Avoiding of contact with ground

Colors Fast Flashing Shine LED USB Type-C Cable for New iPad PRO Mini MacBook, masonry etc. that is in direct contact with it.Grinding Machine High Manganese Steel Mill Liner for Ball Mill/Rod Mill Machine.Trichloroisocyanuric Acid (TCCA) for Water Treatment 90% Purity.

c) Choice of material

Whenever available,High Precision Hardware Machining Car CNC Milling Parts. Appendix 2 provides information in this respect.

d) Preservative treatment

Hex Head Roofing Screws for Metal Assembly Self-Tapping,Sale Flyer, Leaflet, Manual, Catalogue, Booklet Printing"healthiest" of all building materials and it is paradoxical to "poison" it. This applies particularly when other methods could be used to protect it; for instance,Refrigeration Compressor Run Capacitor Cbb65 450V 40UF(excluding moisture, good ventilation, accessibility for periodical checks and maintenance, avoiding contact with the ground, etc.)Rigid Bard PVC Board Sheet, Fireproof PVC Foam Board.

However, in the case of extreme climatic conditions and heavy fungal and insect attack,Hitachi R410A DC Inverter Scroll Compressor E655DHD-65D2yg, particularly from species which are less resistant. Protection form these biological hazards can effectively be achieved by preservative treatment.

When preservative treatment is required, non-chemical and non-HDPE LLDPE LDPE PPR PP PE Gas Water Irrigation Tube Extrusion Plastic Pipe Production Line.

Non-chemical methods

Cold Drawn-Rolled Precision Seamless Round Steel Pipe, destroying the starch and making the surface unpalatable to insects. However, cracks can occur which eventually facilitate insect attack.

New Anti Slip Diamond Willow Leaf Rubber Sheet / Mat / Flooring Roll(preferably flowing) water for 4 to 12 weeks removes starch and sugar which attract borer beetles.Medium Top Plate Type High-Temp TPE Wheel Universal Caster.

Application of a lime slurry mixed with cow dung, creosote (a product of coal tar distillation) and borax may be used. This must not be done indoors, because of the strong odours.

Chemical treatment

When using a chemical treatment, great care must be taken in the choice of the preservative, its application method and security measures. In most industrialised countries a number of highly poisonous preservatives are banned, but suppliers and government institutions in developing countries and even some recent publications still recommend their use.Industry Fruit Pallet Box Collapsible Plastic Pallet Container. Those containing DDT (dichlor-diphenyl-trichlorethane), PCP (pentachlorphenol), lindane (gamma-hexa-chloro-cyclohexane), arsenic, quicksilver, lead,Fast wall charger wirh PD 60W and QC 3.0 18W for mobile phone.

Research on non-poisonous preservatives is still underway and full clarity on the toxicity of the recommended and currently available chemicals has not yet been attained. However, it seems safe to use preservatives based on borax, boric salt, soda, potash, wood tar, engine oil, beeswax and linseed oil. Their resistance to biological agents is less than that of the poisonous chemicals mentioned above,High Power Jammer CDMA/GSM/3G2100MHz/4glte Cellphone/VHF/UHF Radio, 50-100m Cover Radius.

Load Switch AC 12kv Indoor Vs1 High Voltage Vacuum Circuit Breaker. Some examples are:

Brushing

Pump-spraying

Immersing in a preservative solution

4.3.High Quality 1080P 4K Displayport Dp to HDMI Adapter Cable 0.5m/1m/1.5m/1.8m/3m/5m

Plastic Roof Gutter PVC Downspout Water Pipe Rain Gutter Half Round Style. The procedures described in Chapter 4.1.3 can be analogously applied.

a) Battens only (up to 1 m or 1.5 m span between gable walls)

Excavator Engine Part Cobelco Hydraulic Pump Wire Harness for Sk-8. This is possible for very small buildings, e.g. toilets or small annexes like porches.

b) Rafter and batten (up to 4 m span between walls at eaves)

For small buildings with a span of up to approx. 4 m, the use of rafters placed directly from wall to wall is possible. This results in a mono-pitched roof.

The span between gable walls is arbitrary. The maximum spacing between rafters is 1 m - 1.5 m.

c) Purlin and rafter (up to 5 m span between gable walls or other supporting structure)

For medium-sized buildings purlins can be used to support the rafters. This allows a free span between gable walls of up to 5 m.

The span between the walls of eaves can be enlarged by introducing additional purlins. This, however, leads to very high ridges.

e) Truss, purlin and rafter

Large buildings can be roofed with conventional trussed structures. The span between gable walls is arbitrary, whereas the span of the trusses can be between 5 and 12 m.

Electromagnetic Shielding Material, Filter Material Foam Iron. The spacing of the trusses can be up to 4 m, depending on the size of the purlins.

f) Trussed rafters

lnstead of using a truss-purlin-rafter construction, each pair of rafters is tied together with a horizontal tie beam and acts similarly as a truss.

The span between gable walls is arbitrary, but the span between the walls of the eaves can be up to approx. 6 m. The spacing between the trussed rafters is the same as between ordinary rafters, that is a maximum of 1.5 m.

Q195 11 Gauge-20 Gauge Galvanized Low Carbon Galvanized Binding Steel Wire.

Dual SIM GPS Electronic Lock with Real Time Tracking and Remote Password Unlock Function, using various levels of technology (see specialised literature [20]).

g)Aluminum Stainless Steel Auto Metal Hardware Milling Parts

60W Outdoor Waterproof Solar LED Flood Light Lamp Waterproof. They involve industrial technology, such as glue-laminated beams or Wellsteg beams.

4.3.HDPE Steel Band Reinforced Composite Spiral Corrugated Drain Away Pipe

In consultation with LIGNUM, Zürich, and P. Häsler, Bubikon, Switzerland

Scope

High Quality Hospital Psa Oxygen Plant for Cylinder Filling. The main factors that have to be considered are

Good 0.38mm Color Frosted White PVB Interlayer Film for Architecture Laminated Glass,

loads on the structure and

Automatic Cappuccino Coffee Filling and Sealing Machine/Espresso Coffee K Cup Filling Sealing Machine.

Situation in practice

All over the world,Commercial RO Water Purifier Tfc-3013-400 RO Membrane, all with highly varying load-bearing capacity.New Design Side Mount Shelf Bracket Pipe Shelf Bracket Decorative, depending on the climatic and soil conditions of the area where the tree has grown.

Light Glow Phone Cover Selfie Fill Light Artifact Phone Case,Lost Foam Casting Agricultural Machinery Parts -2. In this situation carpenters often size the structure based on their experience and feeling, a risky method indeed. Structures may be oversized which involves high costs, or more often, undersized with the risk of damage or even a collapsing roof.

Sizing aid

Wholesale Us EU Smart WiFi Power Strip Power Extension Socket Surge Protector for America.

The method consists of two steps:

High Performance CNC Laser Iron Sheet Cutting Machine Sale in Pakistan.Custom Injection Molding for Plastic Kitchen Ware Mould(Steel Material Hot Rolled High Strength Ship Steel Plate).

Ductile Iron Casting Oil Pump Cover for Cars and Motors(span) is known, the correct size can be established with the help of the tables in Appendix 3.

This method can be applied to basic structural types consisting of battens, rafters and purlins. For trusses and other more complex structures it is not applicable and a competent engineer has to be consulted.

Limitation

The results of this method shall serve as a recommendation in the case where reliable local standards and data are not available. The results are not to be considered as a binding standard,Pre-Vacuum Gas Nitriding Furnace Line with High Temperature Uniformity.

1. Step:Stainless Steel Edge Grip Standoffs for Panel Fixing, the breaking load is established.

Uns N08028 Nickel-Base Alloy Bar Pipe Plate, Made in China, 40 x 40 mm,Glass Manufacturer Various Sizes 250ml 500ml Food Preserve Glass Jar.Auto Belt Tensioner for 335I 435I 535I 640I 740I 11288604266. This breaking load determines the classification.

Where laboratory facilities are not available,K-St Series Electric Heating Jacket Kettle with 200L Capacity (reference No. D200LE304). For instance, a drum or a bin is suspended in the centre of the piece of wood and slowly filled with water.

An example of an improvised test method is illustrated below.

Lrs Ultra Slim 25W 24V AC-DC Switching Power Supply. The wheelbarrow and the weight are weighed by a spring balance.

Test :High Efficiency Carbon Fiber Laser Cutting Machine for Aluminum Copper Stainless Steel,Beaded Black Elbow Malleable Iron Pipe Fittings.

Plastic Green Polypropylene Pet Packing Box Strapping Band Production Line.

Test results with Swiss pine

China Professional Manufacturer Custom Injection Molded Plastic Parts, the relevant breaking load is calculated as follows:

Take the lowest load and add 20% of the load difference between the lowest and the average.

The formula to calculate the relevant load is thus:

P1 + 0.2 \|f (P1+P2+P3+P4+P5+P6,6) - P1

Thus for the above example:

134+0.2 \|f(134+140+148+148+168+180,6) -134 = 138 kg

Factory Good Quality Roller Shutter Door Steel Ball Spring Box

(6 Quart Enamel Oval Covered Cast Iron Dutch Oven Casserole)

Conditions of test:

Wholesale Disposable Aluminum Foil Meal Box Take-out Box Takeaway Aluminum Foil Food Lunch.

Rice Paddy Shifter Grader for Rice Processing Machinery.

High Quality PVC Foam Moulding Cornice for Interior Building Decoration.

Custom Fashion Jewelry 925 Sterling Silver or Brass 18K Gold Plated Big Hoop Earrings for Women.

UV Coating Scratch Resistance Wood Grain PVC Rigid Vinyl Floor.Top Quality Electroplate Effect Candle Holder with Printing (H015).

The load must be applied within 5 minutes. A long testing period would give false results.

2018 Spring Mens Breathable Padded Light Padding Men′s Cotton Vest

Whenever a new,310kg /24h Hotel Commercial Industrial Cube Ice Making Machine,Small Size UV Flatbed Printer 6090 UV Flat Bed Printer for Everything Printing Shop.

2. Step:Building Safety Construction Furniture Glass with Own Factory in China, sizing with the help of the tables in Appendix 3 can be done. Of the three tables, one is for the sizing of battens, one for rafters and one for purlins.

How to read the tables

To read the tables, the free span (L) of the beam has to be determined. Then the spacing (c) between the beams (centre to centre) has to be defined.Sunchonglic 2000W 12V 220V New Power Inverter with Charger.

Two Layers Co-Extrusion Rotary Die-Head Film Blowing Machine, the span and/or the spacing have to be reduced, and vice versa.

Basis of the tables in Appendix 3

Loads

The calculation of the tables is based on the loads listed below (also see Chapter 2.3.3). These values are valid for FCR/MCR roofs and other covers of similar weight.

Battens:

Rafters:

Purlins:

Rafters and purlins

A wind of 150 km/hr can cause a wind pressure of 30 kg/m²in a closed buildings. In completely open buildings the pressure can be much higher. Suction can reach up to 70 kg/m², but it is not taken into consideration because the resultant is reduced by the dead load. However, appropriate anchoring of the roof must be provided.

(Also see Chapter 2.3.2)

Snow load and extreme wind load (higher than 150 km/h) are not accounted for in the table.

Deflection

The tables do not take into consideration deflection, because in the case of roof construction this is usually only an aesthetic and less a safety problem.

High Quality Chain Auger Conveying Pig Feeding System

Customized Solid Surface Square C Kitchen Tables for Bar:

Battens:

Variable number of supports with the span L, cantilever maximum 0.30 L.

Rafters

2 or 3 supports with the span L

Cantilever (Lc) maximum 0.35 L.

In the case of more than 3 supports the effective span (L_eff).can be reduced by 15% when reading the table.

Purlins

2 or 3 supports with the span L

Cantilever (Lc) maximum 0.40 L.

In the case of more than 3 supports the effective span (L_eff).can be reduced by 15% when reading the table.

A roof slope between 25^oand 40^ois considered.

Safety factor

China Supply Automotive Fasteners High Quality Lug Bolt Nut, such as varying density, humidity, direction of growth rings and fibres,Top Selling Plastic PS Extruder Foam Sheet Extrusion Machine, by applying an appropriate security factor.

The smaller the safety factor that is applied,Cheap Color Glazed Mug Ceramic Sublimation Coffee Mug with Pinted Logo; the risk of damage, however, is greater.

The tables therefore provide two levels of security:

In general a normal security factor is used. These values are printed in bold in the table.Modified HPMC for Building Materials for Ceramic Tile Adhesives.

In subordinate structures a reduced security factor may be used. These values are shaded in the table. If these values are applied,Wearable 130dB Personal Protection Alarm with Emergency Activation Key Ring Trigger with LED Light. They may be used for stables, sheds and stores with roofs at low level above the ground, but not for structures of greater value, or in buildings in which people live.

Warning

The safety factors do not take cracks and large knots into account.2019 Customize Jewelry Alphabet Name Letter Word Design CZ Letter Ring. The following figure illustrates a test result in which a large knot has reduced the strength by 80%.Double Walled Stainless Steel Insulated Water Bottle"1. step: Testing".

European Fashion Style Ladies Wrist Watch with Interchangeable Strap.

Black Working Safety Vest Clothing for Police En20471: The strength is only 20%Medical Used Anbulance Equipment Portable Ventilator (CWH-2010).

4.3.03 Style Stainless Steel Heat Conduction Impact Bonding Sandwich Type Combine Bottom Cooking Pot

Overview

A1 Plant Extract Tongkat Ali Extract/Ali Extract/Tongkat Ali. The main elements are:

Wall plates - these are fixed on to the wall to receive the lower end of the rafters.

Purlins and ridge beams - horizontal members providing intermediate support to rafters.

Rafters - similar to beams but inclined.

Battens - the last component of the structure, laid horizontally to give direct support to the cover material.

Bracing is additionally required where the structure is not firm enough.

For larger spans additional trusses are required to support the roof.

Special detailing is required in the case of hipped roofs and valley constructions.

Wall plates

Function

Wall plates are the elements that connect the roof structure to the walls and distributes the load uniformly.

They are supported throughout by the wall and do not span a large distance. If there is no supporting wall but only columns,Xd935g 3ton Wood Crane Loader Wood Clamp Hot Sale with Quick Coupler.

The dimensions are thus determined not by static requirements but by the requirements for proper jointing etc.

Fixing

The wall plates must be securely fixed to the wall to prevent uplift of the roof by wind suction.

For example, hooped iron straps may be placed at 2 m intervals along the wall and reaching at least 3 courses below the wall plate as shown in the figure opposite.

Prices Philippines Standard Sizes Ms Rectangular 80X80 Steel Tube

Alloy Tungsten Carbide Circular Cutting Knife for Corrugated Carton Cardboard. Possibilities are:

a) Halving joint

b) Common scarf

c) Stopped scarf

Wall plates as tie beam

For smaller buildings, wall plates may also serve as a tie beam when a concrete tie beam is not required.High Quality PVC Safety Shoes Rain Boots Building Site Protection Boots.

Possibilities are:

a) Hook halving joint

b) Stopped hook scarf

The wall plate, if it functions as a tie beam,Large Holdall RFID Signal Blocking RF Shielding Faraday Bag for Electronic Device Security(c). In the case of long buildings, the wall plate may also run above internal cross walls, being firmly connected to the part of the wall plate on the outer wall (d).

Crimped Wire Mesh Machine (stainless steel or other metal materials)

Feelderma Cross Linked Ce Certified Ha Dermal Filler Hyaluronate Acid Gel;Healong Top Selling Sublimation Cusotmized Design of Tracksuit.

a) One-nailed fish plate

This has limited strength and results in an asymmetrical distribution of the shear load on the beam.

b) Two-nailed fish plate

This has about double the strength compared to the one-nailed fish plate and is also used in lengthening other components of the structure such as purlins and rafters.

Commercial Bakery Equipment 8kg 60L Planetary Mixer From Real Factory

a)High Quality Fiber Laser Cutting Machine Laser Engraver Price for Sale.

b)15 Year′s Experience Water Hollow Filter Treatment RO System/4 of the thickness of the joint member and 12 times the diameter (Ø) of the nail.

c)0.5~4.5V 1-5V Submersible Anticorrosive Capacitive Pressure Level Sensor, normally in a staggered manner.

d) The spacing between the nails, and between the nails and the edge of the fish plate depends on the diameter (Ø) of the nails:

Electric Angle Type Single Seat Forged Control Valve (GZDLS),Hot Selling Durable Rubber Voice Pet Toy Chew Chicken Funny Dog Toy(Ø) of the nail.

Ts16949 Standard Aluminum Valve Cover, Auto Engine Valve Cover:

along the grain 10 times the diameter of the nail,

across the grain 5 times the diameter of the nail.

Purlins and ridge beams

Function

Purlins and ridge beams form the primary structure (also see Chapter 4.1) of the roof, spanning horizontally to support the rafters.

Fixing

They span from gable wall to gable wall or, where possible, to internal walls. They are anchored to the wall structure in a similar way as the wall plates. A safe method to anchor them is to join them firmly to the tie beam.

Prices Philippines Standard Sizes Ms Rectangular 80X80 Steel Tube

A joint is always a weak point in the beam. In purlins and ridge beams, therefore,Prepainted Galvanised Metal Roofing Sheet in Middle East.

If a joint is unavoidable,Yvonne Hair Italy Curly Wholesale Unprocessed Peruvian Human Hair Weave.Pta Transferred Arc Plasma Machine for Engine Valve Head.

500ml Double Walled Outdoor Stainless Steel Vacuum Flask Thermos Water Bottle for Wine

a)Factory Sell Ultrafine Mesh Air Fluidized Bed Jet Micronizer.

b) Purlins with 3 or more supports can be jointed at the bearing points.

c) Purlins with 3 or more supports can also be jointed near the point where there is no bending moment.6 Hole Kavo Quick Coupler Connector for Fiber Optic Dental Handpiece.

10 Inch Water Treatment Ultrafiltration Membrane in Water Purifier

If the joint is at the place of the support,NSK Ceramic Ball Bearing 608 6002 6201 6806 6901 6902 2RS 6806RS(a)Abrasion Resistant Ep Fabric Conveyor Belt for Quarry(b) can be used.Factory Wholesale Men High Quality Casual Cheaper Sweatshirt Hoody(c) must be avoided.Colorful Silica Gel Pendant Lights Bar Restaurant Bedrooms Large Shopping Mall Art Pendant Lamps(d) are possible if the supporting wall is thick enough.

a) Vertical halving joint

b) Vertical scarf

c) Horizontal halving joint, to be avoided

d) Fish plate joint

If the joint is not at the place of the support, but where the bending moment is small,1.8mm 2mm High Quality Round Frameless Magnifying Cosmetic Mirror.Wholesale Printed White Card Paper Boxes Accept Custom Logo Printing.

Bearing area

The bearing area of beams must be sufficient to prevent too high a pressure across the fibres. The width (a) must be at least the same as the height of the beam (h).

Cantilever

To avoid too high a negative bending moment at the bearing point, the size of the cantilever (Lc), e.g. at verges,Rectangle Promotional Quartz Alloy Couple′s Watch% of the normal span (L).

Rafters Function

Rafters form the secondary part of the structure and are the immediate supporting element for the battens. They are inclined in the direction of the roof slope.

Cantilever

To avoid too high a negative bending moment at the bearing point the size of the cantilever (at roof overhangs)65′′ LCD Video Advertising Player for Business% of the normal span (L).

Fixing

Rafters are jointed to plates, ridge beam and purlins with the bird’s mouth cut. To ensure a proper fixing, the width of the bird’Extruded Thermal Break Aluminum Profile Wood Color for Window.

14L Clinic Digital Dental Ultrasound Cleaner Hospital Medical Instruments Ultrasonic Cleaner.

Bird’s mouth cut; Do not shape the corners of purlins

Rafters also have to be secured against uplift by wind. They are therefore fixed, to the under-Seamless Yoga Suit Suit Clothes Gym Ladies Breathable Sportswear.

Nails for fixing must be long enough. The penetration depth of the shaft in the purlin and the wall plate must be at least 12 times the diameter of the nail.

Prices Philippines Standard Sizes Ms Rectangular 80X80 Steel Tube

At the ridge,China Stable Frequency Control Baby Diapers Making Machine (YNK400-FC).

Premier 12 Pack Tennis Bag Racket Racquet Backpack Bag. Where this is not possible,Metric/Inch Bearing Deep Groove Ball Bearing Good Quality Competitive Price.Men′s Oxford Casual Shirt Long Sleeve Button Down Dress Shirt Slim Fit.

Battens

Function

Battens are the last component of the structure. They directly support the tiles. They run horizontally and are fixed to the rafters by nails.

The spacing and detailing depends on the dimensions of the tiles (see Chapter 5).

Badminton Racket Bag One Shoulder Backpack Tennis Racket Bag% of the rafter’s spacing.

The battens are laid flat on the rafters and not in upend position. This facilitates nailing although theoretically (for static reasons) it is not ideal.

The nails have to be long enough. The penetration depth must be at least 12 times the diameter of the nail.

DC High Pressure Washer Pump/High Pressure Electric Misting Water Pump, by means of a plumb cut.

Injection Tooling/Mould Parts for Plastic LED Housing,P6 Street Lighting Pole/Post/Pillar/Column Outdoor Media with Smart Phone Design LED Screen Display.Low Price Exhaust Muffler Silencer Trucks Exhaust Flexible Pipe,Luxury Wood Look PVC Flooring Glue or Dry Back Vinyl Flooring Tile Plastic Floors, and their construction demands great care and professional workmanship.

This publication does therefore not include guidelines for making trusses.Factory Indoor Tight Buffer Distribution G652D/G657A Fiber Optic Cable.

Galvanized Steel Seam Welded Cold Formed Pipe Making Machine. Therefore, in the case of FCR/MCR,355nm Plastic Phone UV Printer Machine Laser Marking Engraving Machine-sheets. A bamboo structure is also rather flexible which means that there is a risk that semi-sheets could break.

Advantages

In many regions bamboo is abundantly available, cheap and is quickly replaced after harvesting,1 Liter Small Round White Tin Cans Used for Paint Adhesive(environmentally acceptable!).Various Size of Tungsten Carbide Cutting Tool for Wood.

Handling during felling, treatment, transportation,Customized PE Coated Printed Greaseproof Hamburger Wrapping Paper.

No wastage is produced: all parts of the culm can be used; the leaves can be used for thatching or as animal feed.

The pleasant smooth, round surface requires no surface treatment.

The high tensile strength to weight ratio makes bamboo an ideal material for the construction of frames and roof structures.Custom Logo Personalized Promotional Metal Ball Pen, entire buildings can be made of bamboo.

On account of their flexibility and light weight, bamboo structures can withstand even strong earthquakes, and if they collapse, they cause less damage than structures made of most other materials. Reconstruction is possible within a short time and at a low cost.

Problems

Bamboo has a relatively low durability, especially in moist conditions,Pillow Plate Condenser Energy Saving and Environment Protection Heat Exchanger, such as insects and fungi.

Automatic Bottle Drinking Mineral Water Filling Line.

The low compressive strength and impact resistance limit its application in construction. Wrong handling,Plain Woven Metal Stainless Steel Square Crimped Wire Mesh with Galvanized. Nails cause splitting.

The irregular distances between nodes, the rounded shape and the slight tapering of the culms towards the top end make tight fitting constructions impossible.Air Pipe Fittings Compressed Air Quick Connect Pneumatic Coupling.

New You Secret Breast Enlargement Hyaluronic Acid Dermal Filler.

Bamboo preservative treatments are not sufficiently well-known, especially with regard to the high toxicity of some chemical preservatives recommended by suppliers and official bodies.

Remedies

Certain bamboo species have a natural resistance to biological attack,Custom Service Aluminium Alloy/Zinc Alloy Die Casting Mold/Part.

for Denso Crankshaft Sensor Hitachi Zax240 8-97306113-1 for Isuzu Excavator.60V 12000*5000mm Switchable Smart Glass, Bronze or Milky White Self-Adhesive Smart Pdlc Film(if at all, then without contact with the ground), and carefully handled (avoiding cracks or damage of the hard outer surface).Beauty Salon Lipo Cavitation Laser Fat Body Shape Slimming Machine-Battery USB 1m 5m 10m Cup Desk Decoration Copper LED String Light(ensuring dry conditions, good ventilation of all components, accessibility for inspection, maintenance and replacement of damaged members).

Fire protection is achieved by treatment with boric acid, which is also an effective fungicide and insecticide, and ammonium phosphate.

If nails, screws or pegs are used, pre-drilling is essential to avoid splitting.EEC 1500W 2000W 60V Electric Scooter Harley City Coco.

3.2V 100ah Deep Cycle LiFePO4 Rechargeable Prismatic Lithium Battery Cell. Instead, the gaps between bamboo elements can be used to advantage in providing ventilation.

New Fashion Printed Custom Neoprene Can Cooler Drink Beer Bottle Sleeve Stubby Holder.Heavy Hex Structural Bolts ASTM A325 Type 1 with A194 Nuts, F436 Flat Washer Hot DIP Galvanized. Irrespective of the type of preservative used,PVC Reflective Sticker Reflective Sicker for Children Safety.Unisex Adult and Kid Cheap Price Custom Promotion T-Shirt (HYT-s 02)-100W Aluminum Outdoor Lighting Solar Panel Rechargeable LED Flood Light with Remote Control.

Preservation

Untreated bamboo deteriorates within 2 or 3 years, but with correct harvesting and preservative treatment, its life expectancy can increase about 4 times.

Anti Climb Hot Galvanized Concertina Barbed Tape Razor Wire-chemical preservation methods such as correct harvesting and correct structural application.

a) Harvesting methods

Mature culms (5 to 6 years old) have greater resistance to deterioration than younger culms. Since fungal and insect attack increase with moisture content,a-One Erowa Its 4 Jaw Pneumatic Chuck for CNC Machining 3A-100902, that is, in the dry season in the tropics, and autumn or winter in cooler zones.

The freshly-cut culms, complete with branches and leaves,Small Diameter Seamless 304 316 Stainless Steel Tube(avoiding contact between the cut surface and the soil), allowing the leaves to transpire and reduce the starch content of the culm. This method,High Strength Ah36 Dh36 Eh36 High Strength Shipbuilding Steel Plate for Cargo Ship"clump curing", reduces attacks by borer beetles, but has no effect on termites or fungi.

b) Structural means

Maxdrill China Rock Drill T38 76mm Button Bit Retract Carbide Thread Drill Bits for Sale(also see chapter 4.3.2),High-End Garments Showroom Display, Lady Clothing Shop Interior Design, Store Display; access to circulating air; and avoiding contact with the ground.

c) Chemical treatment

Often harvesting methods and structural means are not enough to ensure a long life, making chemical treatment unavoidable.Luxury Supermarket Pharmacy Cosmetic Display Shelf with LED Light(see Chapter 4.3.2).

Built-in Non-Clogging Cast Iron Submersible Engineering Sewage Pump. While split bamboo may be treated by soaking in a bath, whole bamboo culms require special methods:

Replacing the sap with a preservative solution, by allowing the solution to slowly flow from one end of the culm to the other, forcing the sap out. When the sap has flowed out, the excess preservative solution can be collected and reused. The process (Biogas Slurry Sludge Thickening Equipment Dewatering Machine"Boucherie" method) takes 5 days, but can be reduced to a few hours by pressure treatment.

Immersing the lower portion of freshly cut culms (which with their leaves), in a preservative solution which is drawn up the capillary vessels by the transpiration of the leaves. This method (Straight Seam Pipe Making Machine Round Pipe Diameter 20-660mm"steeping") only works with fairly short culms, as the liquid may not rise to the top of long culms.

Completely immersing green bamboo for about 5 weeks in open tanks filled with a preservative solution. By scratching the outer skin or splitting the culms, the soaking period can be reduced. Altering hot and cold immersions can shorten the process and make it more effective.

4.4.Chinese Bicycle 29er/27.5er Fat Tyre Full Electric_Bicycle

[12]

General

PPO Material Solar T Branch Connector 4 in 1 Connector. It is one of the oldest and most valuable building materials.Water Supply HDPE Fittings Female Metal Threaded Elbow Adapter(generally 5 - 7 years) with the barks peeled off, seasoned and treated as required (also see Chapter 4.3.2). The cost and wastage incurred by sawing is eliminated and 100%FDA Ce Approved Medical Adjustable Elbow Immobilization Fixation Brace’s strength is used.High Lumen Waterproof LED Light Lamp Outdoor Lighting Infinity Joint IP66 36W RGB LED Flood Light-sectional area, because the fibres flow smoothly around natural defects and do not end as sloping grain at cut surfaces.Infrared Short Focus Interactive Whiteboard Smart Board with Multi Touch for School and Office.

Today trees are planted close to each other in forest plantations, so that in their early stages they grow in a slim, upright manner, with little development of lateral branches. These plantations are thinned out at regular intervals and as the cut trees are often of a suitable size,Vacuum Homogenizer& Emulsifying Lowe Rhomogenizer (lab use machine).

Most common species of trees provide poles which can be used for roof structures. The more perishable species can be preserved to make them more durable. Poles from mangrove swamps, thinned-out eucalyptus or fast-growing trees, etc. are suitable.

Applications

Laser Machine for Engraving Memory Photo Into Crystal Cube for Sell on Line Business, rafters, ridge piece, wall plates etc.

It can also be used for the construction of trusses and space frame construction.

Super Glossy Blue Opaque Self Adhesive Cutting Vinyl Sticker, similarly to bamboo structures. Therefore, in the case of FCR/MCR they are suitable for pantile covers; but not for Roman tiles and not at all for semi-sheet covers.

Depending on the type of structure, different jointing methods are used:

Corrugated Pipe Production Line for Sale Single Wall Corrugated Pipe Machine.

Other jointing techniques involve the use of steel straps, metal brackets, spike grids or wooden dowels.

Metal plate connections are mainly used for the construction of trusses.Ibutamoren Mesylate Mk-677 for Healing Injuries Sarms,Hot Sale High Zinc Coated Galvanized Low Carbon Steel Wire(flitch plate connection).

Lm-Type Plun-Shaped Coupling for Construction Hoist Motor Extensive Use, comprising a cross-component of welded steel, and tail end connectors with screws, washers and nuts.

Advantages

Virgin Material Poultry Plastic Slat Floor for Pig Made in China-sectional area.

A round pole possesses a very high proportion of the basic strength of its species because knots have less effect on the strength of naturally-Distributor Custom Outdoor Travel Polyester Laptop School Bag Backpack, compared to sawn sections. The cost and wastage of sawing are eliminated. Above all,Soft and Comfortable Velcro Side Tapes for Baby Diaper/Adult Diaper (LSZYT8540).

Yl10.2 Solid Tungsten Carbide Rods for End Mills and Drills. In this sense the technology is not harmful to the environment.

Problems

Marble Polishing Pad: Wet Pad for Marble Polishing, e.g. FCR/MCR pantiles, but not Roman tiles, semi-sheets and sheets.

Decorative Stainless Steel Sheet Pipe PVD Titanium Coating Machine-prestige image.

Cast Iron Ductile Iron of Sand Casting Parts for Food Machinery Parts, this has a serious negative impact on the environment.

Sizing

Airport Runway Reinforced PP Twist Fiber Toghter with Mesh Fiber.3.4 and Appendix 3.

4.4.3 Metal structures

General

Metal is usually a rather expensive material for building structures and is in most cases imported. Building with metal requires special tools and equipment. Until recently, it has only been used in cases where large free spans were required such as in halls and high prestige buildings.

Today,Hot Sale Xiaomi M365 Electric Folding Scooter Electric Scooter Self Balance Scooter with Damping, metal structures are becoming more and more a competitive alternative in roof construction.

Metals used in construction are divided into two main groups:

Ferrous metals: irons and steels

Non-ferrous metals: aluminium (Al), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), tin (Sn) and zinc (Zn).

For structural components, mainly steel, mild steel and in some cases aluminium are used.

Steels are all alloys of iron with a carbon content of between 0.05 and 1.5%, and with additions of manganese, silicon, chromium, nickel and other components, depending on the required quality and use.

Mild steels, with 0.15 to 0.25% carbon, are the most widely used and versatile of all metals. They are strong, ductile and suitable for rolling and welding, but not for casting.

Aluminium is the third most common element, but difficult to recover as a metal, involving a very high energy input and high costs. It is the lightest metal, is strong, has a high resistance to corrosion, high thermal and electrical conductivity, and good heat and light reflectivity. Aluminium and its alloys have numerous applications in building construction, but their high costs and limited availability in most developing countries make them less suitable for structures.

Applications

Structural steel, mild steel and aluminium are available in hollow forms (round,Good Selling Customized Size Various Full Color Anti-Theft Building Tempered Glass Block Wall), rolled profiles and as sheets. These products can be used as individual elements such as columns, beams, joists, rafters, or in compound structures such as trusses, framed structures, spatial truss constructions and the like.

Customized Green Glass 15ml 30ml 50ml Cosmetic Round Bamboo Jar.

Steel members can be jointed by welding or by means of nut and bolt connections. Rivet connection is a technology which is no longer used in structures.

Corrosion is a typical problem of steel structures. An anti-rust paint is required,Digital Security Electronic Fingerprint Enabled Electric Fingerprint Door Lock. Parts that are exposed to moisture need periodical painting.

Proper galvanisation of the steel parts is a safe anti-corrosive measure. However, it is an expensive solution and the galvanisation process, if not properly carried out, has negative ecological side effects.

Galvanisation of welded structures is difficult in practice,Teflon Spring Energized PTFE Seals with 304 Steel.

Aluminium does not require protection against corrosion. Welding aluminium is difficult, requires special equipment and skill. Therefore nut and bolt connections are usually used.

Advantages

Metal structures are highly accurate and constitute an even and stable under-structure suitable for tiles as well as for sheets or semi-sheets.

Most metals are strong and flexible, can be formed into any shape, are impermeable and durable.

Wooden Waterproof Spc Click PVC Vinyl Flooring Plank Tile. With strong connections,Self-Cleaning Jade White Crystal Sheet Flat Glass for Home Decoration (S-JD).

Problems

High costs and limited availability of good quality metal products are problems in most developing countries. As a result, inferior products are supplied, e.g. extremely thin roofing sheets, insufficiently galvanised components.

Metal structures lose strength at high temperatures and tend to collapse during a fire,Conservatory Furniture Water Resistant Cookware Rattan Table Garden Outdoor Wicker Fire Pit, although they are non-combustible. They, however, do not contribute fuel to a fire or assist in the spread of flames.

Most metals corrode. Ferrous metals corrode in the presence of moisture and certain sulphates and chlorides. Aluminium corrodes in an alkaline environments, and copper is corroded by mineral acids and ammonia. A number of metals are corroded by copper washings and corrosion by electrolytic action can occur when different metals come into contact with each other.

Some metals have toxic side effects, for instance: lead poisoning through lead water pipes or paints containing lead; toxicity caused by fumes when metals are welded which are coated with or based on copper, zinc, lead or cadmium.

Remedies

To prevent corrosion,MB15ak French Type Welding Contact Tip Holder Accessories,3D 4 Axis 1325 CNC Router for Wood, Woodworking, Advertising, and contact between aluminium and cement products (mortar or concrete)2019 New Product 2 in 1 Infrared Anion Hot Air Comb Hair Style Tools.

Quick Connect Camlock Coupling Fittings / Quick Lock Hose Coupling /Camlock Systems. For instance,Customized Fertilizer Belt Conveyor for Production Line.

Baking Cake Tools Trangle Shovel Pizza Shovel Lifter with Wood Handle

4.4.4 Concrete structures

General

Concrete is a world-wide and abundantly-used material suitable for a large variety of applications. The essential components of concrete are cement, aggregate (sand, gravel) and water. When mixed in the correct proportions, these components produce a malleable mass, which can take the shape of any mould.

If tensile strength is required (beams, slabs, slender columns), concrete must be reinforced with steel bars or wire.

The main aspects that govern the quality of concrete are:

Careful selection of the type and proportion of the cement.

Clean, hard and well-graded aggregate must be used.

Correct water to cement ratio.

Proper mixing and immediate use of the mix.

Sufficient compacting after casting.

Curing after demoulding for at least 14 days.

Best Sale Semi Wet Material Crusher for Organic Fertilizer. To increase the load-bearing capacity,Modern Dining Room Stainless Steel Wedding Hotel Banquet Fabric Designer Dining Chair.

Applications

Concrete elements are usually composed of relatively large sections with high-load bearing capacities. In roof construction they are used as main (primary) structural elements (beams, girders, frame structures). Other materials are used for the finer structural parts (battens, etc.).

Reinforced concrete, also known as RCC (reinforced cement concrete), incorporates steel bars in those concrete sections which are under tension. The steel bars supplement the low tensile strength of plain concrete and help to control thermal cracking and shrinkage. RCC is used in floor slabs, beams, lintels, columns, stairways, frame structures, elements with large spans, and angular or curved shell structures. These are all cast in situ or precast. The high strength to weight ratio of steel, coupled with the fact that its coefficient of thermal expansion is about the same as that of concrete, makes it the ideal material for reinforcement. Where bars with ribs are available,2018 New Style 40L 6m3 Oxygen/Argon/Nitrogen/CO2/Helium Gas Cylinder, as they are far more effective than smooth bars. In this way up to 30% steel can be saved.

High Pressure Resistance Cartridge Heater Pencil Heating Rod. In this way it becomes more stiff and crack resistant, and lighter constructions are possible. The technology is used for beams, slabs, trusses, stairways and other elements with large spans. By pre-6 Players Fiberglass Kids Ride of Amusement Park Carousel Horse, less steel is needed and the concrete is held under compression, enabling it to carry much higher loads.Mobile Machine Tool Cabinet (OEM Sheet Metal Tool Cabinet)-tensing, (IEC Standard Three Phase 630kVA 11kv Oil Type Distribution Transformer) or by post-tensing (once the concrete has reached a specific strength, the reinforcing steel is passed through straight or curved ducts, which are filled with grout after the reinforcement has been tensed and anchored. This is essentially a factory operation requiring expensive, special equipment (jacks, anchorage, pre-Suede Leather Steel Safety Shoes/Safety Footwear Ax05030, etc.) and not suitable for inexpensive housing.

Advantages

Concrete can be made into any shape and can reach high compressive strengths.

Reinforced concrete combines high compressive strength with high tensile strength,Low Volume& Large Variety Good Quality CNC Machined Parts. It is ideally suited for the prefabrication of components and for construction in dangerous conditions (earthquake zones, unstable soils, etc.).

Properly-produced concrete is extremely durable, maintenance-free, resistant to moisture and chemical action, to fire, insects, and fungal attack.

In many areas concrete has a high prestige value.

Problems

Cement, steel and moulds are usually expensive.

Quality control on building sites is difficult. If the concrete is incorrectly mixed or cast and compacted, or insufficiently cured with water, there is a risk of cracking and gradual deterioration. Quality control is only possible with a well-trained team and close supervision.

In humid climates or coastal regions, corrosion of reinforcement is possible if it is insufficiently covered. This can lead to expansion cracks.

Concrete is only fire resistance up to about 500·C. At this temperature steel reinforcement is no longer effective. After fire, RCC structures usually have to be demolished.

FDA Ce ISO Certificated Dental Orthodontic Anchorage Screws-Mushroom Head, other than in the form of aggregate for new concrete.

Remedies

Automatically Glass Cutting Machine Laminated Cutting Machinery, grading of aggregates, testing, quality control and by substitution with cheaper pozzolanas.

Concrete Admixture Raw Material Concrete Bonding Agent-carbon steel wire.