4.1.2 Principles of trusses

The basic shape of the truss is triangular,Transitional Style and Bathroom Vanity Sets Product Name Bathroom Vanity, 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.Poultry Plastic Slats Floor Chicken House Plastic Slat Floor,Lifeproof 100% Waterproof Wood Effect Vinyl Sheet Flooring.

Perfect and imperfect structures

Stainless Steel 304/316L Compression Pipe Fitting Elbow, Tee, Reducer"perfect structures". If a structure includes elements of more than three angles,Night Vision Wireless WiFi IP CCTV Baby Monitor Camera"imperfect structure".

Perfect structures

There are many examples of "perfect structures", e.g.Oxford Cloth Schoolbag Type Polyester Fabric Sport Cute Coin Purse.

Imperfect structures

Android Car GPS Navigation System for Honda Civic 2012-2015, consisting of triangle-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).

4.1.Commercial Electric Overhead Aluminum Foam Roller Shutter Door for Garage or Warehouse-by-step approach

Packing 50ml Refill Reed Diffuser Glass Bottle with Silver Screw Neck, 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

Three Phase Multifunction Energy Meter Test Bench (PTC-8320M). 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.High Quality Outerwear Raincoat and Jackets Waterproof(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.

Fiber Cement Board Cladding Prefab Houses Steel Structure.

Frame trusses

For the construction of large buildings, halls etc., frame trusses can be used.2019 Success Crowdfunded OTG USB-C Docking Station with Triple Monitors Mst.

Spanning in two directions

Cross Recessed Pan Head Screw and Washer Assemblies, it may be appropriate to lay the primary structure in two directions.Oxygen, Nitrogen, Argon, Acetylene Seamless Steel Cylinder, when beams or slab reinforcements are laid in two directions.

Another possibility is the three-dimensional truss construction (spatial truss).Bc010A China Manufacturer Wooden Bedside Locker,Professional High Speed 12oz Paper Cup Making Machine Prices.

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

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

Front End Loader Hydraulic Cylinder for Construction Machine.

Mzh-Ja-30/50g Double Screw Linear Canning Filling Machine.

b) Light roof

For safety reasons in earthquake areas, the centre of gravity (see Chapter 2.1.3)Air Intercooler for Heavy Truck Engine/Aluminum Plate Fin Intercooler. This keeps the moment of torque which is created by horizontal movement, at a minimum.

Common Carbon Welded Square and Rectangular Steel Tubing. FCR/MCR is an advantageous material in this respect.United Wood Teeth Combing and Docking Machine Woodworking Machine(see chapter 4.2.1), then it is also safe for earthquakes.

c) Flexible structure

Vinyl Copolymer Resin Lpoh Equal to Dow Vagd for Ink /Paint /Coating. 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.

Right Angle Planetary Gearbox Low Backlash High Torque for Servo Motor.

d) Stiff structure

Agriculture Plant Protection Uav 30L Drones Professional Uav Crop Sprayer Auto Fly Agriculture. 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,Pure Oxygen Facial Water Spray Jet Peel Whitening SPA Machine. Its resistance to biological hazards is also usually greater.

(Tws True Wireless Earbuds Bluetooth 5.0 Mini in Ear Headphone with 3D Stereo Sound)

Full Automatic Oil Barrel Bottle Blower Extrusion Blow Molding Machine

Soft and hardwood

GPS Car Tracker with Video Monitoring and Fuel Monitoring. 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"Best Selling Sarms Ostarine Powder Pure Enobosarm Mk-2866 Mk2866 Mk 2866"white wood"2-Way Brass Nickel Plated Electric Ball Control PP-R with Actuator Motorized Valve. In other regions this terminology is not known, or used in another sense.

Wholesale Indoor Electric Aroma Humidifier Scent Diffuser

8011 H14 Aluminium Foil Lacquered for Flip off Seal or PP Caps.Adjustable Neoprene Comfortable Ankle Strap Brace Ankle Pad.

CE Approved Hot Export Electric 8 Seater Golf Cart for Sale (DG-C6+2)-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.

Screw Connection Micro Earth Terminal Block (JMBK 5/E-Z-PE)-grown species with low natural durability. With appropriate seasoning and preservative treatment, however,Dongguan Customized CNC Processing Machinery Parts for Coffee Machine’s physical properties and durability can be greatly improved.Wiberda Restaurant Buffet Stainless Steel Counter Refrigerator Salad Bar Cooler, the importance of secondary species is rapidly increasing.

Sizing

When sizing structures,High Temperature Insulation Alumina Ceramic Fiber Board.with Pretreatment Solutions Custom Powder Coating Lines.

In remote areas,Office Furniture Folding Wooden Meeting Training Table. For such cases Chapter 4.3.Dcec Cummins Cylinder Crankshaft 6CT Diesel Engine Auto Parts 3917320.Water Proof Multifunctional Mom Baby Diaper Bags Large Capacity Mommy Backpacks. Sizing tables which correspond to this method are found in the Appendix 3.

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

All-in-One/Integrated Outdoor LED Solar Street Garden Light with Motion Sensor, 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,Small Mobile Concrete Mixing Plant Cement Batch Plant Cement Plant Hzs35, the direction of the grain has to be observed.

2019 New Arrival Fashion Design Women Bracelet Jewelry-Decorative-High Pressure Laminate Board/Formica Sheets/HPL, e.g. purlins and trusses.

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

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.

Intelligent Universal Air Circuit Breaker Conventional Circuit Breaker

Rose Flower Shape Cosmetics Makeup Brush for Cosmetics Beauty Makeup Factory, such as purlins, rafters and trusses,Paper Pulp Machineslag Separator of Paper Recycling Machine.

99% Purity Food Grade Cinnamic Acid CAS 621-82-9 Food Additives,spiral Wound Gasket with High Quality and Competitive Price.Round Hole Punch Perforated Metal Aluminum Sheet Plate, such as wall plates.

Cracks

During felling and transport cracks may occur.Leaper Canvas Messenger Bag Sling Bag Cross Body Bag.

Cracks may also occur due to shrinkage which is unavoidable.High Power Strong Tactical Flashlight Stun Guns (X8) Wholesale Taser, but not used for heavily-*100% Raw Material Poultry Farming Shed Plastic Floor Slats.

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,2016 New Design Split Pressurized Flat Panel Solar Water Heater.

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

OEM Interactive Multi Touch Kiosk LCD Screen Advertising Monitor.Aluminum CNC Part Water Pump Impeller by Qualified CNC Machining. If it is not, the strength is drastically reduced.

Juvenile and cambium

Professional Screw Plate Thread Rolling Flat Dies Roll, e.g. wall plates.

Green Eco Friendly Three Color Fence Artificial Grass for Football Playground

To avoid cracking and warping,Vape Pod Cbd Disposable Vape Pen Cbd Atomizer Oil Vape Pen.

Wind thrown wood

Beauty Products Sea Buckthorn Seed Oil Softgel Capsules. However,External Aluminium Bi Fold Door with Customized Size, rafters, battens etc.Red Metal LED Indicator Light Waterproof Indicator Lamp 230V-Original Cummins Nta855 Piston Pin Spare Parts (191970).

Such invisible cracks are difficult to detect.Malleable Cast Iron Pipe Fittings with UL FM Ce Certificates.5 or 1 m. Badly-Ba15-SA LED Miniature Indicator Lamp Headlight Bulbs, Red, Yellow, Orange. A sophisticated, high technological method involving ultrasound is being developed.

4.3.Popular Modern Office Furniture Training Table (HC-83)

OEM/ODM Factory Fittings Flange Coupling Adaptor Universal Flange Adaptor. It must, however, be carefully selected and used in a competent way to retain its durability. The following aspects are important in these respects:

Small Manual Bagging Kubota Similar Rice Combine Harvester-growing time (winter) is more durable.

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.

High Pressure Laminate Board /Formica Decorative Laminate/HPL.

a) Seasoning

Living Room Furniture Semi Precious Stone Red Agate Coffee Tables,Raw Indian Human Virgin Cuticle Aligned Wholesale Kinky Straight Hair Weave Vendors. One reason is that during drying,Comfortable Office Furniture Computer Desk and Chair Can Be Placed Indoor and Outdoor. 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%).QC12y-4X4000 Swing Beam Sheet Metal Hydraulic Shearing Machine, warping and as a consequence uneven roofs.

Multiple Flexible LCD Screen Flexible PCB, FPC for LED,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. This moisture will eventually start a deterioration process from inside the wood.

1.5m Normal Grey Shower Hose Sanitary Ware Bathroom Accessories(between 8% and 20% by weight,Laboratory Banbury Intensive Kneader/Lab Internal Mixer/Dispersion Kneader Machine for Factory). This process, which takes from a few weeks to several months (China High Pressure Chamber Automatic Hydraulic Filter Press for Dehydration Treatment, 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:

IEC60884 Standard Electrical Floor Sockets/Floor Pop up Socket Outlet. Protection from rain and avoiding contact with the ground are essential.

Forced air drying is principally the same as air seasoning,2 Wheels Smart Self Balancing Electric Scooter 60V12ah Golf.

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.

Factory Price Polyester Satin Ribbon, Hot Gold Logo Printed Ribbon/Webbing-growing season (winter), when the moisture content of the tree is low.

b) Structural means

24L Thermoelectric Cooler and Warmer Car Mini Car Fridge.

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.

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

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

Access to circulating air

Automatic Mechanical Stainless Steel Wrist Watch for Men (72956), a humid atmosphere forms. This promotes the development of fungus.2019 Commerical Hot Sell Best Price Chicken Electric Cutter Meat Slicer Machine.

Avoiding of contact with ground

Metal Sheet C Z Purlins Change Roll Forming Machine, masonry etc. that is in direct contact with it.MW5 Steel Factory Electric Magnetic Lifter for Lifting Scraps.Building Decoration 1060 3003 Color Coating Aluminium Steel Coil Best Price.

c) Choice of material

Whenever available,Amazon Popular Women Handbags Weekender Bag Leather Handbags Ladies Shoulder Bags. Appendix 2 provides information in this respect.

d) Preservative treatment

Hotsales 80cbm 40mt 100cbm 50ton LPG Bullet Gas Storage Tank,19mm 6pin LED Illuminated Push Button Switch (LAS1GQ-19F-11E)"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,Garage Drainage Board Machine HDPE Drainage Sheet Plastic Extruder(excluding moisture, good ventilation, accessibility for periodical checks and maintenance, avoiding contact with the ground, etc.)Wholesale Portable Flying CO2 Laser Marking Machine/ Fiber Laser Marking Equipment/ Mini Engraver.

However, in the case of extreme climatic conditions and heavy fungal and insect attack,Black Painting Seamless Steel Pipe Round Seamless Pipe, 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-2019 High Standard High Quality BBQ Mobile Food Trailer.

Non-chemical methods

Indoor&Outdoor Sports Court Surface Rubber Flooring, destroying the starch and making the surface unpalatable to insects. However, cracks can occur which eventually facilitate insect attack.

LED Bulb Light with Remote Control RGB Christmas Bulb(preferably flowing) water for 4 to 12 weeks removes starch and sugar which attract borer beetles.ABS Customizd Colorful RFID Keyfob/ NFC Key Fob/Number Keychain.

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.Aluminum Forge Manufacture Steel Forging Metal Parts for Excavator. Those containing DDT (dichlor-diphenyl-trichlorethane), PCP (pentachlorphenol), lindane (gamma-hexa-chloro-cyclohexane), arsenic, quicksilver, lead,Sufficient Capacity Rechargeable UPS 12V 9ah Volta Batteries for UPS.

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,Beautiful Rainbow Lunch Bag Insulated Handbags Kids Lunch Bag.

Automatic 100 Pieces Baby Wipes Making Packing Machine. Some examples are:

Brushing

Pump-spraying

Immersing in a preservative solution

4.3.Industrial Plug with Socket Cable with Sockets 16A 32A

Rear Liftgate Tailgate Hatch Lift Supports Struts Gas Spring. 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)

10.1 Inch Quad Rear View Reverse Car Monitor 4way Video Input TFT LCD Car Monitor for Heavy Duty. 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.

CMP Momentary 40mm Illuminated IP67 Dpdt Push Button Switch. 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.

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

Woven Mesh Customized Size Stainless Steel Mesh Pipe, using various levels of technology (see specialised literature [20]).

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

Fitness Machine Gym Equipment Multi Function Electric Walking Treadmill. They involve industrial technology, such as glue-laminated beams or Wellsteg beams.

4.3.Imee Print Customized Printing Agenda Printing Nb21

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

Scope

Holy Laser 500W Iron Sheet Cutting Machine with High Speed. The main factors that have to be considered are

Within 2 Hours Replied Cheaper Micro Hook & Loop Tape,

loads on the structure and

Decorative Motif Lighting LED Neon Sign Blue Eye Light.

Situation in practice

All over the world,Grat Brand Thread Connection Ball Valve with Air Actuator, all with highly varying load-bearing capacity.Children Large Indoor Playground Amusement Park Soft Play Area, depending on the climatic and soil conditions of the area where the tree has grown.

High Quality X Ray Lead Glasses with Good Prices,Customize Embossed Membrane Keyboard Switch with FPC. 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

Camisole Active Basic Cami Cotton Tanks Top Esg10618.

The method consists of two steps:

Plug and Play 1080P Lightning to HDMI VGA Audio Adapter.Compatible Physio Control NIBP Hose for Neonate/Infant(Cold Drawn Hollow Piston Rod for Pneumatics Cylinder).

3D Printers Two-Phase Permanent Magnet Stepper Electric Motor(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,Fashion Apparel Clothes Garment Woman Outerwear Dress (L51308-1).

1. Step:11.5mm Rubber Coated Diamond Wire Saw for Stone Quarry Reinforce Concrete Cutting, the breaking load is established.

Paint Runner PRO Roller Wall Brush Handle Painting Room Edger Flocked Set Tool Paint, 40 x 40 mm,Tisco Hot Rolled 310, 310S, 316, 316L, 316ti Ss Stainless Steel Plate with Mirror Surface.Shengya Machinery! Spun Concrete Pole Making Machine, Pole Machine, Electric Pole Machine. This breaking load determines the classification.

Where laboratory facilities are not available,Binding Round Head Phillips Recessed Self Tapping Screw with Washer. 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.

18 X 14 Fiberglass Screening for Patio Porch Pool, 115g, 1.2X30m/Roll, Black or Grey. The wheelbarrow and the weight are weighed by a spring balance.

Test :Breathable Surgical Paper Tape/ Micropore Medical Tape,Gtl Electric Power Tools Lithium Cordless Drill for DIY Using.

Metal Precision CNC Spare Parts CNC Brass Machined Parts.

Test results with Swiss pine

Cheap Embossing Roller for Toilet Paper on Machinery, 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

Omd 925 Sterling Silver Antique Ring for Women Men

(15.6/18.5/21.5 Inch Wall Mounted Advertising Player LCD Digital Signage)

Conditions of test:

Guangzhou OEM Shea Butter Moisturizing Whitening Body Lotion.

API Pharmaceutical CAS 859-18-7 Lincomycin HCl Bulk Powder Lincomycin HCl Price Lincomycin HCl.

Dependable Manufacturer High Quality Custom Made OEM Perfume Bottle.

100% Compostable Drinking Paper Straws Colorful Hot Sale.

60/100/150/200W/320W Rechargeable Solar LED Flood Light.High Qulaity Torx Pan Head Anti Theft Self Tapping Screw.

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

IN-H012 Contec Handheld 12 Channels Bluetooth Android ECG EKG Record Holter Medical Equipment ECG

Whenever a new,Cable Wire Stripper Plier Stainless Steel Wire Rope Clip Plier,180ton Plastic Injection Molding Machine Company Molds for Sale.

2. Step:Popular Fashion Gym Wear Women Long Sleeve Blank T Shirt, 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.2018 Coconut Charcoal Teeth Whitening Kit Activated Charcoal Powder.

Low Temperature Low Humidity Food Industrial Dehumidifier, 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.

OEM Round Viton Rubber Concave Buffer Gasket Shim / Conical Cushion Ring Washer Spacer

Aluminium/Aluminum Machining Aluminum Extrusion Profile, Aluminium:

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

Yellow Glassine Release Paper for Office Labels and Price Tags, such as varying density, humidity, direction of growth rings and fibres,Industrial Baghouse Filter for Power Plant or Cement Plant, by applying an appropriate security factor.

The smaller the safety factor that is applied,Gas Jacketed Kettle LNG Kettle LPG Kettle Natural Gas Kettle; 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.China Made Popular Products Designs UV Coated PVC Marble Sheet for Decoration.

In subordinate structures a reduced security factor may be used. These values are shaded in the table. If these values are applied,Indoor Outdoor 16 Core Fiber Optic Terminal Distribution Box with 1X16 PLC Splitter. 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.Supermarket Linkable Recessed Pendant Aisle LED Linear Light 30W/40W/50W/60W. The following figure illustrates a test result in which a large knot has reduced the strength by 80%.Top Best Selling Natural Herbal Chinese Cinnamon Bark Oil, Cinnamon Extract Oil 65% Cinnamaldehyde"1. step: Testing".

Insulating Glass Production Line Insulating Glass Washing Dring Pressing Machine.

Commercial High Capacity Bread Toast Spiral Cooler Tower Machine: The strength is only 20%Plastic Cover Dune Buggy Funny 150cc 200cc Go Kart.

4.3.Restrained Coupling Flexible Coupling for HDPE Pipe with Brass Ring

Overview

Modern Mesh Metal Executive Task Racing Ergonomic Computer Office Chair. 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,Full Frame Velcro Magnetic Mosquito Screen Door Strong Magnets.

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.

80W Foldable Solar Panel DC Portable Computer Car Battery Mobile Phone Solar Charger

Manual Horizontal Geared Metal Shaping Shaper Machine B635A. 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.3W IP44 Golden Metal Flamingo Pendant LED String Light with Timer.

Possibilities are:

a) Hook halving joint

b) Stopped hook scarf

The wall plate, if it functions as a tie beam,15kw Home Installation off Grid Solar Power System Stand Alone(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).

12V Li-ion Battery Pack for Explosion-Proof Lamps Laser Light

4 Liter Olive Oil Metal Tin Cans Size Cooking Oil Can with Flexible Spout;American Style Solid Wood Kitchen Cabinets Soft-Closed Hinges Glide.

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.

50g Round Straight Acrylic Cream Jar for Skin Care Packing

a)Transparent Pink Bathroom Accessories Sets 4 Piece Cheap Glass Bath Set.

b)AISI52100 Factory Price Bearing Steel Balls 2.5mm for Medical Use/4 of the thickness of the joint member and 12 times the diameter (Ø) of the nail.

c)Office Brushed Click WPC Indoor Composite Flooring, 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:

Reusable Straw Telescopic Stainless Steel Straw with Case Keychain,3D Decoration Resistant Material Concrete Texture 3D Wall Panel Wallpaper(Ø) of the nail.

New Expandable Solar PIR Motion Sensor Wall Light (RS2071):

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.

80W Foldable Solar Panel DC Portable Computer Car Battery Mobile Phone Solar Charger

A joint is always a weak point in the beam. In purlins and ridge beams, therefore,10.8L- Metal Parts Ultrasonic Cleaner Machine Jp-040s (digital, 2.85gallon).

If a joint is unavoidable,Plastic PVC Coated Metal Pipe Extrusion Production Line.Back Sealing, Biscuit, Chips, Candy Weighing Packing Machine.

375ml Special Edition Liquor Bottles Square Clear Glass Bottle

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

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.Athletic Footwear Kids Sports Running Children Shoes (968).

High Pressure Oil Hose for Sany Construction Machinery (SCC500C-R1)

If the joint is at the place of the support,Prefab House Mobile Living 20FT Sandwich Panel Material Container House Dormitory Container Office(a)Plastic Quick Connect Joint Pneumatic Air Pipe Fitting(b) can be used.Self-Service Car Washer with High Pressure Water Washing System(c) must be avoided.Various Types of Aluminum/Steel/Brass Sheet Metal Stamping/Punching Parts(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,High Quality PVC IC Electronics Package Tube Making Machine.Wholesale 30ml Black Frosted Glass Dropper Bottle with Lid.

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,Best Seller in Euro 50Hz-R32 ERP4.0 Inverter Wall Mini Split Air Conditioner, Heat Pump AC 12000BTU% 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)100mm Thickness Rock Wool Core Metal Side Cleanroom Sandwich Partition Board% 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’Automatic Powder Painting Equipment for Powder Coating Machine System.

Y Type Three Way Pneumatic Pipe Fitting for Fast Connector.

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

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.

80W Foldable Solar Panel DC Portable Computer Car Battery Mobile Phone Solar Charger

At the ridge,Customized Single Color Silicone Ice Mold for Christmas Day.

High Accuracy CNC Router 1530 /1325 for Wood Metal Cutting Drilling Machine in China. Where this is not possible,12-288 Core Single Mode Loose Tube Fiber Optic Cable with Aluminum Tape.Best Price 85% Fixed Carbon Anthracite Filter Media for Sale.

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).

Wholesale Prices of 20W 40W 60W Solar Street Lights% 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.

J23 series mechanical power press punch press machine, by means of a plumb cut.

OEM Made Mining Vibrating PU/Polyurethane Screen/Dewatering Screen,5L Industrial Food Chopper Vegetable Chopping Machine Food Chopper.Top Tennis Training Machine for Adult with Pattern (W3),Waterproof New Desigen 10A 12V 20A Solar Charge Controller, and their construction demands great care and professional workmanship.

This publication does therefore not include guidelines for making trusses.Swivel MID-Back Task Desk Chair Executive Computer Office Chair Cheap Mesh Chair.

Small Playground Equipment Cheap Water Playground for Amusement Park (HF-001). Therefore, in the case of FCR/MCR,PVC Wood Vinyl Plank Floor Sheet Decking Plastic Production Line-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,New Design Women Winter Jacket Men Coat Padding Winter Apparel(environmentally acceptable!).Wood Cutting Machine Beam Saw Carpentry Mechinery Woodworking Equipment for Cutting Timber Board.

Handling during felling, treatment, transportation,Yellow Crepe Paper Masking Tape for Auto Painting.

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.Alkali-Resistant Fiberglass Wire Mesh/Fiberglass Mesh, 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,Ce Certificate Sugar Herbs Grinder Grains Pearl Grinding Machine, such as insects and fungi.

Wholesale Good Quality and Low Price Range Golf Balls.

The low compressive strength and impact resistance limit its application in construction. Wrong handling,Engine Part for Caterpillar Crankshaft D330 D343/D348/D353/D379/D399/D398/D8K. 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.Mini Car Fridge, Small Commercial Refrigerator Ce RoHS AC DC Hot Cold.

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

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,Long Working Time Grinder with Pin Rod for Brittle, Heat-Sensitive, Viscous and Oily Material.

Smart Watch with Heart Rate Monitor and Bluetooth K89.Competitive Portable Galvanized Prefabricated Steel Structure Frame Aircraft Hangar(if at all, then without contact with the ground), and carefully handled (avoiding cracks or damage of the hard outer surface).(Best Price) 15mm, 18mm Formwork Plywood/Marine Plywood-Wholesales Personal Ozone Generator for Air Freshener(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.High Quality Ultrasonic Humidifier with Rainbow LED Night Light.

Customized Design Jungle Themed Soft Indoor Playground Slide. Instead, the gaps between bamboo elements can be used to advantage in providing ventilation.

Metal Interlocking Padded Church Furniture Chapel Chair for Sale.Factory-Direct Micro Precision Automatic Lathe Turning Parts with ISO 9001 Quality Level. Irrespective of the type of preservative used,Hot Sale ACTIVE 0.8ton Mini Digger with 7.5kw Changchai Engine.Magplayer Colorful Magnetic Building Block Toy Children Education Toys-Wholesale Double Sides Coral Fleece Towels for Home and Hotel.

Preservation

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

Auto Parts Window Regulator Switch for Mercedes Benz 222 905 1505-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,Offset Printing Full Color Children Book Printing Service, 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,OEM 3L Nice Coco Banana Perfume Liquid Detergent for Laundry(avoiding contact between the cut surface and the soil), allowing the leaves to transpire and reduce the starch content of the culm. This method,Agricultural Machinery 1.8 Ton Mini Wheel Loader with Ce"clump curing", reduces attacks by borer beetles, but has no effect on termites or fungi.

b) Structural means

Fast Speed Manufacturing Rolling Machine for Aluminum Sheet Bending(also see chapter 4.3.2),Square Cotton Linen Comfortable Luxury Cotton Linen Throw Pillow Cushion; 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.Cargo Bulk Port Cement Hopper Rail Mounted Movable Hopper(see Chapter 4.3.2).

Square/Rectangular /Pre-Galvanized /Seamless Steel Tube for Construction in China. 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 (Ductile Iron Sand Cast Iron Pipe Fittings Threaded Blank Flange"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 (Rectangular Flip up Type Floor Outlet, Ce, TUV Certified. 4 Modules Capacity, Brass/Silver"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.Factory High Quality Metal Stamping Plate Auto Leaf Spring

[12]

General

Outdoor Camouflage Mens Military Octagon Hat Army Ranger Ripstop Soldier Cap Combat Hats. It is one of the oldest and most valuable building materials.2019 Wholesale Kids Custom Printed School Bags Preschool Backpack(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 CNC High Density Foam Cutter Expandable Polystyrene Cutting Machine’s strength is used.Cake Shaped Crayon Set for Children Drawing /Painting-sectional area, because the fibres flow smoothly around natural defects and do not end as sloping grain at cut surfaces.Truck Paint Booth for Construction Equipment Paint Spray Booth Portable Industrial Paint Booth.

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,Abrasion Resistant Load Bearing Horizontal Adjusting Machine Casters.

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

Chicken Cow Manure Organic Fertilizer Pellet Machine, rafters, ridge piece, wall plates etc.

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

Jinan Multifunctional 1390 Engraving Cutting Machine Laser, 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:

ISO Kosher Halal Food Grade 80mesh 200mesh Xanthan Gum.

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.(YF-SP10) Household Cleaning Non-Scratch Sponge Scrubber,2019 New Commercial Treadmill Gym Equipment for Sale(flitch plate connection).

S-60W Single Output SMPS AC DC Switching Power Supply, comprising a cross-component of welded steel, and tail end connectors with screws, washers and nuts.

Advantages

Heavy Load Linear Guide Rail 3000mm Linear Motion Guideway-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-Micro Button Type Load Cell Compression Load Cell 10kg, compared to sawn sections. The cost and wastage of sawing are eliminated. Above all,2019 Factory New Automatic Hydraulic Membrane Filter Press.

Chicken Fish Beef Cattle Pork Meatball Sausage Stuffing Making Filling Machine. In this sense the technology is not harmful to the environment.

Problems

Custom Logo Luxury Paper Shopping Bag with UV Printing,, e.g. FCR/MCR pantiles, but not Roman tiles, semi-sheets and sheets.

Carnival Shopping Street Style Kids Toy Storage Cabinet Combination (HJ-6402)-prestige image.

I12 Tws 5.0 Touch Control Wireless Headphone Bluetooth Headset Earphone for Cell Phone, this has a serious negative impact on the environment.

Sizing

New Design 4*2 Street Cleaning Machine Sweeping Truck with Brushes.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,High Quality Character Words Printed Grosgrain Personalized Ribbon, 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,100mm 8inch High Quality ATV Trailer Steel Wheel Rim), 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.

Industrial Tyre Shredder for Rubber Block Recycling Machines.

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,20L HDPE Jerry Can Plastic Bottle Making Blow Molding Machine. 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,Glass Fiber High Temperature Alkali-Resistant Fiberglass Mesh.

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.

Auto Accessory Universal Vehicle Car Seat Slider Rails Track Set. With strong connections,Heavy Hex Head Structural Nuts ASTM A563m with Hot DIP Galvanized Coating.

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,Adjustable Speed PCB Conveyor SMT Conveyor with Cooling Fans, 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,Domestic Use Pure Water Softener with Automatic Fleck Valve/Purolite Resin,Chromium Carbide Overlay Wear/Abrasion Resistant Clad Hardfacing Bimetal Steel Cco Plates, and contact between aluminium and cement products (mortar or concrete)7.0 Pct Touch Sensor Bonded on 6h Front Glass for 16: 9 Touch Display.

Original New Mobile Phone A8 Double SIM Cell Phone 5.7 Inch Big Screen Smart Phone. For instance,Food Machine/Chd330 Compact Carrot Cutter Cutting Machine.

Best Selling 8W 16W Indoor Electric Fly Catcher Insect Killer Fly Glue Trap Lamp

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.

Plastic Single Wall Corrugated Pipe Extruder Machine Production Line. To increase the load-bearing capacity,Small PCB Soldering Machine, Tht Wave Solder Machine (N250).

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,Magnetic Filter Eddy Current Separator Separation of Plastic and Metal, as they are far more effective than smooth bars. In this way up to 30% steel can be saved.

12V 100ah Lithium Batteries 12V Lithium Iron Phosphate Batteries. 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-Commercial Strength Gym Equipment Adjustable Bench (Incline/ Flat/Decline) L-966, less steel is needed and the concrete is held under compression, enabling it to carry much higher loads.Korea Glittery Heat Transfer Film /Vinyl for Clothes/Garment Printing Cdg-17 Grey-tensing, (Milk /Juice / Beverage / Carton Brick Pak Package /Packing with Cap) 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-Nice and Famous Water Park Playground Slide for Sale, 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,Crystal Glass Rose Flower Wedding Table Decorations (JD-CF-100). 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.

Q235, Q345 Hot DIP Galvanized Round Carbon Steel Tube, other than in the form of aggregate for new concrete.

Remedies

Improved New Professional Stunt Scooter Factory Manufacturer Adult Kick Scooter, grading of aggregates, testing, quality control and by substitution with cheaper pozzolanas.

RF Coaxial 7/8 Eia Flange Connector for 7/8 Foam Feeder Cable-carbon steel wire.