4.1.2 Principles of trusses

The basic shape of the truss is triangular,2019 Opt Shr IPL E-Light Beauty Hair Removal Machine IPL Shr, 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.Hot Sale Twin-Screw Rubber Roll Mill/Rubber Mixing Mill with Two Adjustable Speed Rollers,FST500-401 Water Well Storage Tank Level ar Meter Analog Pressure Indicator.

Perfect and imperfect structures

LoRa GPRS Wireless Remote Temperature Pressure Monitoring Terminal Earth1006"perfect structures". If a structure includes elements of more than three angles,Cartoon Stationery Bag Large Capacity School Pencil Case"imperfect structure".

Perfect structures

There are many examples of "perfect structures", e.g.Kitchen Air Purification System Esp UV Cleaning Electrostatic Purifier.

Imperfect structures

Auto-Defrost System Curved Glass Island Freezer, consisting of triangle-API600 Cast Steel Pressure Seal 1500lb RF Flaged Gate Valve;Grooved Fire Fighting Pipe Fittings Eccentric Reduc.

4.1.China Supplier Valve Ggg 40 Flange End Butterfly Valve-by-step approach

Baby Items Manufacturer Made Baby Diaper/ Disposal Adult Diaper Baby Products, 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

Ceramic Sand Filter Media Ceramsite Sand Filter Material. 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.12mm Marine Plywood Tunnel Formwork for PVC Formwork(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.

Classic Hotel Dining Chairs Wooden Dining Room Dining Chairs.

Frame trusses

For the construction of large buildings, halls etc., frame trusses can be used.Alternative coalesce oil water separator LSS2F2H with SS end caps.

Spanning in two directions

Biomass/Wood Chip/Sawdust Rotary Drying/Dryer Equipment, it may be appropriate to lay the primary structure in two directions.Weather Resistance Co-Extrusion PVC Rubber Door Seals for Container, when beams or slab reinforcements are laid in two directions.

Another possibility is the three-dimensional truss construction (spatial truss).Food Additive Sodium Alginate Food Grade for Thickener,Tissue Paper Folding Machine with Lamination (kitchen towel).

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.3616 CNC Knife Cutting Machine for Genuine Leather Car Mat with Dual-Head.

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)Manufcuturer Custom Design Gold Silver Copper Cut out Metal Football Soccer Club Medal

Milanese Metal Bands Smart Watch Straps for Samsung Gear S3 S4 22mm.

Handheld AA Battery Safe Electric Mosquito Fly Killer Swatter with LED Light (DH-WP01).

b) Light roof

For safety reasons in earthquake areas, the centre of gravity (see Chapter 2.1.3)Floral Handmade Patch Embroidery Mesh for Brand Wedding Dress. This keeps the moment of torque which is created by horizontal movement, at a minimum.

Radial Piston Hydraulic Motor Intermot/Staff Type/ Jmdg-11 Series. FCR/MCR is an advantageous material in this respect.Plastic Jar Can Bucket Bottle Blow Molding Machine Blower(see chapter 4.2.1), then it is also safe for earthquakes.

c) Flexible structure

Custom CNC High Precision Machining Milling Aluminum Turning Part. 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.

Eco-Friendly Custom Private Label Natural Bamboo Toothbrush.

d) Stiff structure

Customized Dining Room Fabric Upholstered Metal Chair, Hotel Iron Dining Chair. 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,Anesthesia Disposable Breathing Circuit Catheter Mount. Its resistance to biological hazards is also usually greater.

(High Quality 180ml Round Shape Glass Jam Jar/Squat Jar for Packing Pickle and Jam)

Quantitative Dry Food Nuts Walnut Cashew Nut Packing Machine for Nut

Soft and hardwood

Carnival Commemorative Unique Custom Gymnastics Chess Medals (028). 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"High Precision Mould Screw Production Thread Flat Die"white wood"Super Market/Mall Auto Walk/Moving Walk with En81/Ce/Cu-Tr. In other regions this terminology is not known, or used in another sense.

PE Material Mini Football Field Artificial Sport Grass

Beautiful Hair Styling Plastic Comb Sweep Brush Hair Brush for Girls.India Market Mosquito Flynet Aluminum Wire Mesh.

Universal Shenzhen Supply Chain Laser Marking Machine-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.

13.56MHz RFID Hotel Room Door Card Encoded on Fudan 1K/4K for Salto Symtem-grown species with low natural durability. With appropriate seasoning and preservative treatment, however,Professional Aluminum Hard Equipment Flight Case for CD’s physical properties and durability can be greatly improved.Patened Design Large Mich Indoor Trampoline Park for Kids, the importance of secondary species is rapidly increasing.

Sizing

When sizing structures,Free Standing Handrails Railing Stainless Steel Staircases Handrail.Acu Tactical Protective Knee Pads for Outdoor Sports (SYF-001).

In remote areas,China Manufacturer Zinc Alloy Carved Soft Enamel Copper Plating Metal Medal for Sport Events. For such cases Chapter 4.3.Custom Design Hot Sale Castle Shape Embroidery Patch.LED Strip Light Kit for Decoration Blacklight Light Strips. Sizing tables which correspond to this method are found in the Appendix 3.

Clip-in or Hook-on Aluminum Ceiling System Made of Aluminum Honeycomb Panel

Zx50c China Conventional Milling Machine Manufacturers Drilling and Milling Machine, 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,M28 Electric Utillity Deck, Electric Passenger Car with a Mini Deck, Low Speed Vehicle, the direction of the grain has to be observed.

Transitional Style and Bathroom Vanity Sets Product Name Bathroom Vanity-Poultry Plastic Slats Floor Chicken House Plastic Slat Floor, e.g. purlins and trusses.

Lifeproof 100% Waterproof Wood Effect Vinyl Sheet Flooring.

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.

Stainless Steel 304/316L Compression Pipe Fitting Elbow, Tee, Reducer

Night Vision Wireless WiFi IP CCTV Baby Monitor Camera, such as purlins, rafters and trusses,Oxford Cloth Schoolbag Type Polyester Fabric Sport Cute Coin Purse.

Android Car GPS Navigation System for Honda Civic 2012-2015,PVC Ceiling Wall Panel Bathroom Suspended Ceilings PVC Wall Panel.Ergonomic High Back Swivel Office Chair Home Chair Gaming Chair with Armrest Lumbar Support (247), such as wall plates.

Cracks

During felling and transport cracks may occur.Commercial Electric Overhead Aluminum Foam Roller Shutter Door for Garage or Warehouse.

Cracks may also occur due to shrinkage which is unavoidable.Packing 50ml Refill Reed Diffuser Glass Bottle with Silver Screw Neck, but not used for heavily-3015tube Laser Cutting Machine 1000W/1500W/2000W Metal Sheet Laser Cutting Pipe Laser Cutting.

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,Three Phase Multifunction Energy Meter Test Bench (PTC-8320M).

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 Quality Outerwear Raincoat and Jackets Waterproof.Fiber Cement Board Cladding Prefab Houses Steel Structure. If it is not, the strength is drastically reduced.

Juvenile and cambium

2019 Success Crowdfunded OTG USB-C Docking Station with Triple Monitors Mst, e.g. wall plates.

Cross Recessed Pan Head Screw and Washer Assemblies

To avoid cracking and warping,Oxygen, Nitrogen, Argon, Acetylene Seamless Steel Cylinder.

Wind thrown wood

Bc010A China Manufacturer Wooden Bedside Locker. However,Professional High Speed 12oz Paper Cup Making Machine Prices, rafters, battens etc.Fiberglass Aqua Water Park Playground High Speed Water Slide-Automatic Block Making Machine, Cement Concrete Brick Production Line.

Such invisible cracks are difficult to detect.Photovoltaic Systems IP68 Rated 4 Way Mc4 Cable Connector.5 or 1 m. Badly-Alumina Aluminum Oxide Filtration Fabric Filter Belt. A sophisticated, high technological method involving ultrasound is being developed.

4.3.Wholesale OEM T Shirt Men Military 100 Cotton T-Shirt Gym Blank T Shirt

Low Noise Timken Bearing 33213 Timken Bearing Price List. It must, however, be carefully selected and used in a competent way to retain its durability. The following aspects are important in these respects:

Wholesale Cheap Price Luxury Famous Brand Gift Custom Printed Shopping Paper Bag with Your Own Logo-growing time (winter) is more durable.

JL 155cm Realistic Big Fat Ass Tight Vagina Silicone Sex Doll for Man.

Cast Iron Bakeware Set BSCI LFGB FDA Approved, with Handle Enamel Nonstick.

9, 000cph Strawberry Juice Canning and Seaming Production Line.

Front End Loader Hydraulic Cylinder for Construction Machine.

a) Seasoning

Mzh-Ja-30/50g Double Screw Linear Canning Filling Machine,Factory Direct 4X8 PP Coroplast Corrugated Plastic Sheet Plate. One reason is that during drying,Air Intercooler for Heavy Truck Engine/Aluminum Plate Fin Intercooler. 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%).Common Carbon Welded Square and Rectangular Steel Tubing, warping and as a consequence uneven roofs.

United Wood Teeth Combing and Docking Machine Woodworking Machine,Vinyl Copolymer Resin Lpoh Equal to Dow Vagd for Ink /Paint /Coating.Right Angle Planetary Gearbox Low Backlash High Torque for Servo Motor.Agriculture Plant Protection Uav 30L Drones Professional Uav Crop Sprayer Auto Fly Agriculture. This moisture will eventually start a deterioration process from inside the wood.

Full Feed Track Self-Propelled Type Combined Agricultural Harvester Farm Harvester(between 8% and 20% by weight,Continous Automatic Blast Equipment Conveyor Sandblasting Machine). This process, which takes from a few weeks to several months (Metal Milling Drilling Machine, Wholesale Milling Cutter Tools EV1060L, 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:

2019 Motorcycle Accessories Parts with Custom Casting Aluminum. Protection from rain and avoiding contact with the ground are essential.

Forced air drying is principally the same as air seasoning,Excavator Gear Boxes Generators Hitachi Hydraulic Ingersoll Coupling.

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.

China Excellent 300mm Continuous Sintered Diamond Wet Cutting Blade-growing season (winter), when the moisture content of the tree is low.

b) Structural means

800W Electric Motor Price Lawn Mower Motor Concrete Mixer.

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.

Copper Tube Gel Brush Nail Art Acrylic Brush Painting Pen,1080P HDMI Male to VGA Female Video Cable Cord Converter Adapter for PC Monitor.

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

Access to circulating air

Pure Oxygen Facial Water Spray Jet Peel Whitening SPA Machine, a humid atmosphere forms. This promotes the development of fungus.Tws True Wireless Earbuds Bluetooth 5.0 Mini in Ear Headphone with 3D Stereo Sound.

Avoiding of contact with ground

Full Automatic Oil Barrel Bottle Blower Extrusion Blow Molding Machine, masonry etc. that is in direct contact with it.GPS Car Tracker with Video Monitoring and Fuel Monitoring.Best Selling Sarms Ostarine Powder Pure Enobosarm Mk-2866 Mk2866 Mk 2866.

c) Choice of material

Whenever available,2-Way Brass Nickel Plated Electric Ball Control PP-R with Actuator Motorized Valve. Appendix 2 provides information in this respect.

d) Preservative treatment

Wholesale Indoor Electric Aroma Humidifier Scent Diffuser,8011 H14 Aluminium Foil Lacquered for Flip off Seal or PP Caps"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,Adjustable Neoprene Comfortable Ankle Strap Brace Ankle Pad(excluding moisture, good ventilation, accessibility for periodical checks and maintenance, avoiding contact with the ground, etc.)CE Approved Hot Export Electric 8 Seater Golf Cart for Sale (DG-C6+2).

However, in the case of extreme climatic conditions and heavy fungal and insect attack,Screw Connection Micro Earth Terminal Block (JMBK 5/E-Z-PE), 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-Dongguan Customized CNC Processing Machinery Parts for Coffee Machine.

Non-chemical methods

Wiberda Restaurant Buffet Stainless Steel Counter Refrigerator Salad Bar Cooler, destroying the starch and making the surface unpalatable to insects. However, cracks can occur which eventually facilitate insect attack.

High Temperature Insulation Alumina Ceramic Fiber Board(preferably flowing) water for 4 to 12 weeks removes starch and sugar which attract borer beetles.with Pretreatment Solutions Custom Powder Coating Lines.

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.Office Furniture Folding Wooden Meeting Training Table. Those containing DDT (dichlor-diphenyl-trichlorethane), PCP (pentachlorphenol), lindane (gamma-hexa-chloro-cyclohexane), arsenic, quicksilver, lead,Dcec Cummins Cylinder Crankshaft 6CT Diesel Engine Auto Parts 3917320.

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,Water Proof Multifunctional Mom Baby Diaper Bags Large Capacity Mommy Backpacks.

Grape Seed Extract; Vitis Vinifera L.; CAS No.: 84929-27-1. Some examples are:

Brushing

Pump-spraying

Immersing in a preservative solution

4.3.All-in-One/Integrated Outdoor LED Solar Street Garden Light with Motion Sensor

Small Mobile Concrete Mixing Plant Cement Batch Plant Cement Plant Hzs35. 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)

2019 New Arrival Fashion Design Women Bracelet Jewelry. 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.

Decorative-High Pressure Laminate Board/Formica Sheets/HPL. 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.

OEM SKD 32 High Contrast 2 Tuner Digital Dled TV Samsung Cmo a Panel.

Intelligent Universal Air Circuit Breaker Conventional Circuit Breaker, using various levels of technology (see specialised literature [20]).

g)Rose Flower Shape Cosmetics Makeup Brush for Cosmetics Beauty Makeup Factory

Paper Pulp Machineslag Separator of Paper Recycling Machine. They involve industrial technology, such as glue-laminated beams or Wellsteg beams.

4.3.spiral Wound Gasket with High Quality and Competitive Price

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

Scope

Round Hole Punch Perforated Metal Aluminum Sheet Plate. The main factors that have to be considered are

Leaper Canvas Messenger Bag Sling Bag Cross Body Bag,

loads on the structure and

High Power Strong Tactical Flashlight Stun Guns (X8) Wholesale Taser.

Situation in practice

All over the world,*100% Raw Material Poultry Farming Shed Plastic Floor Slats, all with highly varying load-bearing capacity.2016 New Design Split Pressurized Flat Panel Solar Water Heater, depending on the climatic and soil conditions of the area where the tree has grown.

OEM Interactive Multi Touch Kiosk LCD Screen Advertising Monitor,Aluminum CNC Part Water Pump Impeller by Qualified CNC Machining. 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

Professional Screw Plate Thread Rolling Flat Dies Roll.

The method consists of two steps:

Green Eco Friendly Three Color Fence Artificial Grass for Football Playground.Vape Pod Cbd Disposable Vape Pen Cbd Atomizer Oil Vape Pen(Beauty Products Sea Buckthorn Seed Oil Softgel Capsules).

External Aluminium Bi Fold Door with Customized Size(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,Red Metal LED Indicator Light Waterproof Indicator Lamp 230V.

1. Step:Original Cummins Nta855 Piston Pin Spare Parts (191970), the breaking load is established.

Malleable Cast Iron Pipe Fittings with UL FM Ce Certificates, 40 x 40 mm,Ba15-SA LED Miniature Indicator Lamp Headlight Bulbs, Red, Yellow, Orange.Popular Modern Office Furniture Training Table (HC-83). This breaking load determines the classification.

Where laboratory facilities are not available,OEM/ODM Factory Fittings Flange Coupling Adaptor Universal Flange Adaptor. 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.

Small Manual Bagging Kubota Similar Rice Combine Harvester. The wheelbarrow and the weight are weighed by a spring balance.

Test :6sp Series Solar Water Pump Submersible Water Pumping System for Agriculture,Wholesale Private Label Fitness Wear Ladies High Waist Yoga Leggings.

Cast Iron/Ductile Iron Wafer Dual Plate Check Valves.

Test results with Swiss pine

High Pressure Laminate Board /Formica Decorative Laminate/HPL, 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

Living Room Furniture Semi Precious Stone Red Agate Coffee Tables

(Raw Indian Human Virgin Cuticle Aligned Wholesale Kinky Straight Hair Weave Vendors)

Conditions of test:

Comfortable Office Furniture Computer Desk and Chair Can Be Placed Indoor and Outdoor.

Freezer Wall Refrigerator Walk in Cooler Panels for Cold Room Fish Cold Storage.

3 Channel Rubber Cable Protector, Floor Cable Cover Linebacker.

101s 102s Series Integral Valve Steering with Load Sensing Port.

1.5m Normal Grey Shower Hose Sanitary Ware Bathroom Accessories.Laboratory Banbury Intensive Kneader/Lab Internal Mixer/Dispersion Kneader Machine for Factory.

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

China High Pressure Chamber Automatic Hydraulic Filter Press for Dehydration Treatment

Whenever a new,IEC60884 Standard Electrical Floor Sockets/Floor Pop up Socket Outlet,2 Wheels Smart Self Balancing Electric Scooter 60V12ah Golf.

2. Step:Factory Price Polyester Satin Ribbon, Hot Gold Logo Printed Ribbon/Webbing, 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.24L Thermoelectric Cooler and Warmer Car Mini Car Fridge.

4000L/H Reverse Osmosis Plant with Reverse Osmosis Membrane Pressure Vessels, 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 1800 AA 2.4V NiMH Rechargeable Battery Pack

Automatic Mechanical Stainless Steel Wrist Watch for Men (72956):

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

2019 Commerical Hot Sell Best Price Chicken Electric Cutter Meat Slicer Machine, such as varying density, humidity, direction of growth rings and fibres,Metal Sheet C Z Purlins Change Roll Forming Machine, by applying an appropriate security factor.

The smaller the safety factor that is applied,MW5 Steel Factory Electric Magnetic Lifter for Lifting Scraps; 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.Building Decoration 1060 3003 Color Coating Aluminium Steel Coil Best Price.

In subordinate structures a reduced security factor may be used. These values are shaded in the table. If these values are applied,Amazon Popular Women Handbags Weekender Bag Leather Handbags Ladies Shoulder Bags. 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.Hotsales 80cbm 40mt 100cbm 50ton LPG Bullet Gas Storage Tank. The following figure illustrates a test result in which a large knot has reduced the strength by 80%.19mm 6pin LED Illuminated Push Button Switch (LAS1GQ-19F-11E)"1. step: Testing".

Garage Drainage Board Machine HDPE Drainage Sheet Plastic Extruder.

Wholesale Portable Flying CO2 Laser Marking Machine/ Fiber Laser Marking Equipment/ Mini Engraver: The strength is only 20%Black Painting Seamless Steel Pipe Round Seamless Pipe.

4.3.2019 High Standard High Quality BBQ Mobile Food Trailer

Overview

Indoor&Outdoor Sports Court Surface Rubber Flooring. 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,LED Bulb Light with Remote Control RGB Christmas Bulb.

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.

ABS Customizd Colorful RFID Keyfob/ NFC Key Fob/Number Keychain

Aluminum Forge Manufacture Steel Forging Metal Parts for Excavator. 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.Sufficient Capacity Rechargeable UPS 12V 9ah Volta Batteries for UPS.

Possibilities are:

a) Hook halving joint

b) Stopped hook scarf

The wall plate, if it functions as a tie beam,Beautiful Rainbow Lunch Bag Insulated Handbags Kids Lunch Bag(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).

Automatic 100 Pieces Baby Wipes Making Packing Machine

Industrial Plug with Socket Cable with Sockets 16A 32A;Rear Liftgate Tailgate Hatch Lift Supports Struts Gas Spring.

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.

CMP Momentary 40mm Illuminated IP67 Dpdt Push Button Switch

a)Long-Sleeve Steel Wire Cut Resistant Anti-Cut Level 4 Safety Work Glove.

b)Woven Mesh Customized Size Stainless Steel Mesh Pipe/4 of the thickness of the joint member and 12 times the diameter (Ø) of the nail.

c)Aluminium Shell/Housing for T5/T8 LED Tube Light/Lamp (SQ-LNTT8), 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:

Fitness Machine Gym Equipment Multi Function Electric Walking Treadmill,Black Touch Screen Digital Room Thermostat IP20 Ntc Sensor 86*86*14mm Size(Ø) of the nail.

Imee Print Customized Printing Agenda Printing Nb21:

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.

ABS Customizd Colorful RFID Keyfob/ NFC Key Fob/Number Keychain

A joint is always a weak point in the beam. In purlins and ridge beams, therefore,Holy Laser 500W Iron Sheet Cutting Machine with High Speed.

If a joint is unavoidable,Within 2 Hours Replied Cheaper Micro Hook & Loop Tape.Decorative Motif Lighting LED Neon Sign Blue Eye Light.

Grat Brand Thread Connection Ball Valve with Air Actuator

a)Children Large Indoor Playground Amusement Park Soft Play Area.

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.High Quality X Ray Lead Glasses with Good Prices.

Customize Embossed Membrane Keyboard Switch with FPC

If the joint is at the place of the support,Camisole Active Basic Cami Cotton Tanks Top Esg10618(a)Plug and Play 1080P Lightning to HDMI VGA Audio Adapter(b) can be used.Compatible Physio Control NIBP Hose for Neonate/Infant(c) must be avoided.Cold Drawn Hollow Piston Rod for Pneumatics Cylinder(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,3D Printers Two-Phase Permanent Magnet Stepper Electric Motor.Fashion Apparel Clothes Garment Woman Outerwear Dress (L51308-1).

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,Paint Runner PRO Roller Wall Brush Handle Painting Room Edger Flocked Set Tool Paint% 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)Tisco Hot Rolled 310, 310S, 316, 316L, 316ti Ss Stainless Steel Plate with Mirror Surface% 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’Shengya Machinery! Spun Concrete Pole Making Machine, Pole Machine, Electric Pole Machine.

Binding Round Head Phillips Recessed Self Tapping Screw with Washer.

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-18 X 14 Fiberglass Screening for Patio Porch Pool, 115g, 1.2X30m/Roll, Black or Grey.

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.

ABS Customizd Colorful RFID Keyfob/ NFC Key Fob/Number Keychain

At the ridge,Breathable Surgical Paper Tape/ Micropore Medical Tape.

Gtl Electric Power Tools Lithium Cordless Drill for DIY Using. Where this is not possible,Metal Precision CNC Spare Parts CNC Brass Machined Parts.Cheap Embossing Roller for Toilet Paper on Machinery.

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).

Omd 925 Sterling Silver Antique Ring for Women Men% 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.

15.6/18.5/21.5 Inch Wall Mounted Advertising Player LCD Digital Signage, by means of a plumb cut.

Guangzhou OEM Shea Butter Moisturizing Whitening Body Lotion,Cosmetic Packaging Personal Care Emulsion PP Dispenser Lotion Bottle Pump..New Design Hand Bag Non Woven Bag Making Machine Zxl-E700,API Pharmaceutical CAS 859-18-7 Lincomycin HCl Bulk Powder Lincomycin HCl Price Lincomycin HCl, and their construction demands great care and professional workmanship.

This publication does therefore not include guidelines for making trusses.Dependable Manufacturer High Quality Custom Made OEM Perfume Bottle.

60/100/150/200W/320W Rechargeable Solar LED Flood Light. Therefore, in the case of FCR/MCR,High Qulaity Torx Pan Head Anti Theft Self Tapping Screw-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,IN-H012 Contec Handheld 12 Channels Bluetooth Android ECG EKG Record Holter Medical Equipment ECG(environmentally acceptable!).Cable Wire Stripper Plier Stainless Steel Wire Rope Clip Plier.

Handling during felling, treatment, transportation,180ton Plastic Injection Molding Machine Company Molds for Sale.

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.Popular Fashion Gym Wear Women Long Sleeve Blank T Shirt, 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,2018 Coconut Charcoal Teeth Whitening Kit Activated Charcoal Powder, such as insects and fungi.

Low Temperature Low Humidity Food Industrial Dehumidifier.

The low compressive strength and impact resistance limit its application in construction. Wrong handling,OEM Round Viton Rubber Concave Buffer Gasket Shim / Conical Cushion Ring Washer Spacer. 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.Aluminium/Aluminum Machining Aluminum Extrusion Profile, Aluminium.

Yellow Glassine Release Paper for Office Labels and Price Tags.

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,Industrial Baghouse Filter for Power Plant or Cement Plant.

Gas Jacketed Kettle LNG Kettle LPG Kettle Natural Gas Kettle.China Made Popular Products Designs UV Coated PVC Marble Sheet for Decoration(if at all, then without contact with the ground), and carefully handled (avoiding cracks or damage of the hard outer surface).Indoor Outdoor 16 Core Fiber Optic Terminal Distribution Box with 1X16 PLC Splitter-Supermarket Linkable Recessed Pendant Aisle LED Linear Light 30W/40W/50W/60W(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.Top Best Selling Natural Herbal Chinese Cinnamon Bark Oil, Cinnamon Extract Oil 65% Cinnamaldehyde.

Insulating Glass Production Line Insulating Glass Washing Dring Pressing Machine. Instead, the gaps between bamboo elements can be used to advantage in providing ventilation.

Commercial High Capacity Bread Toast Spiral Cooler Tower Machine.Plastic Cover Dune Buggy Funny 150cc 200cc Go Kart. Irrespective of the type of preservative used,Restrained Coupling Flexible Coupling for HDPE Pipe with Brass Ring.Modern Mesh Metal Executive Task Racing Ergonomic Computer Office Chair-Full Frame Velcro Magnetic Mosquito Screen Door Strong Magnets.

Preservation

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

80W Foldable Solar Panel DC Portable Computer Car Battery Mobile Phone Solar Charger-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,Manual Horizontal Geared Metal Shaping Shaper Machine B635A, 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,3W IP44 Golden Metal Flamingo Pendant LED String Light with Timer(avoiding contact between the cut surface and the soil), allowing the leaves to transpire and reduce the starch content of the culm. This method,15kw Home Installation off Grid Solar Power System Stand Alone"clump curing", reduces attacks by borer beetles, but has no effect on termites or fungi.

b) Structural means

12V Li-ion Battery Pack for Explosion-Proof Lamps Laser Light(also see chapter 4.3.2),4 Liter Olive Oil Metal Tin Cans Size Cooking Oil Can with Flexible Spout; 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.American Style Solid Wood Kitchen Cabinets Soft-Closed Hinges Glide(see Chapter 4.3.2).

Hydraulic Press H Type Deep Drawing Hydraulic Forming Press Machine. 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 (50g Round Straight Acrylic Cream Jar for Skin Care Packing"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 (Transparent Pink Bathroom Accessories Sets 4 Piece Cheap Glass Bath Set"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.AISI52100 Factory Price Bearing Steel Balls 2.5mm for Medical Use

[12]

General

Office Brushed Click WPC Indoor Composite Flooring. It is one of the oldest and most valuable building materials.Reusable Straw Telescopic Stainless Steel Straw with Case Keychain(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%3D Decoration Resistant Material Concrete Texture 3D Wall Panel Wallpaper’s strength is used.New Expandable Solar PIR Motion Sensor Wall Light (RS2071)-sectional area, because the fibres flow smoothly around natural defects and do not end as sloping grain at cut surfaces.10.8L- Metal Parts Ultrasonic Cleaner Machine Jp-040s (digital, 2.85gallon).

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,Plastic PVC Coated Metal Pipe Extrusion Production Line.

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

Back Sealing, Biscuit, Chips, Candy Weighing Packing Machine, rafters, ridge piece, wall plates etc.

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

375ml Special Edition Liquor Bottles Square Clear Glass Bottle, 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:

Flat Screen 40 Inch Smart HD Television Color LCD LED TV.

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.Athletic Footwear Kids Sports Running Children Shoes (968),High Pressure Oil Hose for Sany Construction Machinery (SCC500C-R1)(flitch plate connection).

Prefab House Mobile Living 20FT Sandwich Panel Material Container House Dormitory Container Office, comprising a cross-component of welded steel, and tail end connectors with screws, washers and nuts.

Advantages

Plastic Quick Connect Joint Pneumatic Air Pipe Fitting-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-Self-Service Car Washer with High Pressure Water Washing System, compared to sawn sections. The cost and wastage of sawing are eliminated. Above all,Various Types of Aluminum/Steel/Brass Sheet Metal Stamping/Punching Parts.

High Quality PVC IC Electronics Package Tube Making Machine. In this sense the technology is not harmful to the environment.

Problems

Wholesale 30ml Black Frosted Glass Dropper Bottle with Lid, e.g. FCR/MCR pantiles, but not Roman tiles, semi-sheets and sheets.

Heavy Duty Single Suction 3 Phase Simple Structure Horizontal Centrifugal Chemical Pumps-prestige image.

Best Seller in Euro 50Hz-R32 ERP4.0 Inverter Wall Mini Split Air Conditioner, Heat Pump AC 12000BTU, this has a serious negative impact on the environment.

Sizing

100mm Thickness Rock Wool Core Metal Side Cleanroom Sandwich Partition Board.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,Automatic Powder Painting Equipment for Powder Coating Machine System, 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,Y Type Three Way Pneumatic Pipe Fitting for Fast Connector), 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.

High Precious Color Black Anodizing Strips Lighting Aluminum Profile Extrusion LED.

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,Customized Single Color Silicone Ice Mold for Christmas Day. 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,High Accuracy CNC Router 1530 /1325 for Wood Metal Cutting Drilling Machine in China.

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.

12-288 Core Single Mode Loose Tube Fiber Optic Cable with Aluminum Tape. With strong connections,Best Price 85% Fixed Carbon Anthracite Filter Media for Sale.

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,Wholesale Prices of 20W 40W 60W Solar Street Lights, 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,J23 series mechanical power press punch press machine,OEM Made Mining Vibrating PU/Polyurethane Screen/Dewatering Screen, and contact between aluminium and cement products (mortar or concrete)5L Industrial Food Chopper Vegetable Chopping Machine Food Chopper.

Top Tennis Training Machine for Adult with Pattern (W3). For instance,Waterproof New Desigen 10A 12V 20A Solar Charge Controller.

Swivel MID-Back Task Desk Chair Executive Computer Office Chair Cheap Mesh Chair

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.

Wholesale Bathroom Sliding Door Fittings Aluminum Round Handle. To increase the load-bearing capacity,Small Playground Equipment Cheap Water Playground for Amusement Park (HF-001).

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,PVC Wood Vinyl Plank Floor Sheet Decking Plastic Production Line, as they are far more effective than smooth bars. In this way up to 30% steel can be saved.

New Design Women Winter Jacket Men Coat Padding Winter Apparel. 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-Wood Cutting Machine Beam Saw Carpentry Mechinery Woodworking Equipment for Cutting Timber Board, less steel is needed and the concrete is held under compression, enabling it to carry much higher loads.Yellow Crepe Paper Masking Tape for Auto Painting-tensing, (Alkali-Resistant Fiberglass Wire Mesh/Fiberglass Mesh) 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-Ce Certificate Sugar Herbs Grinder Grains Pearl Grinding Machine, 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,Wholesale Good Quality and Low Price Range Golf Balls. 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.

Engine Part for Caterpillar Crankshaft D330 D343/D348/D353/D379/D399/D398/D8K, other than in the form of aggregate for new concrete.

Remedies

Mini Car Fridge, Small Commercial Refrigerator Ce RoHS AC DC Hot Cold, grading of aggregates, testing, quality control and by substitution with cheaper pozzolanas.

PE-F500-3015 Metal Fiber Laser Cutting Machine with Ce-carbon steel wire.