Steel Workshop House
Steel workshop house mainly refers to the main load-bearing components which are made of steel. The load-bearing components includes steel columns, steel beams, steel base, steel trusses (now the large span of the plant are basically with steel trusses), steel roof and steel wall with bricks protected. More and more plants are adopted steel structure, because the steel output of China is increased. There are two kinds of steel workshop house, one is light steel structure, the other is heavy steel structure. The industrial and civil facilities constructed of steel are called steel structures.
Characters of Steel Workshop House:
- Light weight, high strength and large span;
- Short construction time leads to lower investment costs;
- Fire resistance and anti-corrosion;
- Convenient to move and pollution-free recycling.
Performances of Steel workshop house
- Shock Resistance
The roof of villa is sloping, therefore the roof structure is basically adopted triangular roof truss system of cold-formed steel components. After sealed off the structural sheet and the gypsum board, the cold-formed steel components would form the ‘Plate Rib Structure system’ which has strong abilities of anti-seismicity and horizontal load resistance. It is usually adapted to the place where requires the seismic fortification intensity of 8 degree or above.
- Wind Resistance
Lightness, strength and rigidity have characterized the steel-structure building. The weight of building is only one-fifth to brick-concrete structures, but it would well protect human life and property away from the hurricane up to 70 meters per second.
The house structure of lightweight steel construction is built according to cold-formed and thin-walled steel component system. Their steel ribs are made of cold-rolled galvanized sheets of anti-corrosion, high strength, so it keeps the steel plate away from corrosion, and increase life time of steel components. The life time of house structure can is up to 100years.
- Thermal Insulation
The thermal insulation material is based on glass fiber which performs well heat insulation. To make it better, the outer walls with insulation board will effectively prevent the cold bridge effect. Thermal resistance of R15 insulation cotton in 100mm thickness is equal to the brick wall in 1m.
- Acoustical Insulation
Performance of acoustical Insulation is an important indicator of housing. The hollow glass window installs in lightweight steel structure, which soundproofing is up to 40 db or above. The walls made of lightgage steel joist and gypsum board proofs the sound up to 60 db.
Dry construction would alleviate the waste to pollute environment. The steel structure material can be 100% recycled, while most of other supporting system materials also can be recycled. All the materials comply to ecosystem requirements, they are the green building materials and harmless to health.
The lightweight steel walls are adopted energy-efficient system which has the respiratory function to adjust the indoor air humidity. The rooftop is ventilated, so that it forms the air flow overhead to ensure ventilating and cooling inside.
All the jobs are dry construction, they are unlimited by the seasons. For example, to complete a building of 300㎡, it only needs 5 workers with 30 days from laying the foundation to decorating.
- Environmental Protection
The materials can be 100% recycled which is truly environmentally friendly and clean.
- Energy Conservation
With the assistance of energy-efficient walls, thermal insulation, acoustical Insulation, the steel-structure construction system can save 50% energy.
Advantage and Disadvantage
- Widely used: it suitable to factories, warehouses, office buildings, gymnasiums, airports and so on. It is adopted to large-span buildings with single layer, as well was the high-rise or multi-layer.
- Simple construction, short time: all the components are prefabricated. All needed to do is assembling, so it certainly shorten construction period. For example, a building of 6000㎡,it only requires 40 days to complete basically.
- Wear well, easy maintenance: the steel construction designed by computer is able to withstand harsh weather and easy to maintain.
- Artistic and practical: the steel construction has clean and smooth lines, as well as modem sense. There are many kinds of color for wall panel, and many materials for walls.
- Reasonable cost: lightweight to lower the cost of laying foundation, short construction period to operate early. The overall economic efficiency is much better than concrete construction.
Analysis of Quality of Steel Construction Engineering
The difficulties to guarantee the quality of steel construction engineering have many kinds of reason, such as inappropriate processes, process operating problems, builders’ problems and decision makers’ fault on the quality.
- Problem of Steel Materials
Once a certain unit was welding on 1200*1200*60mm box columns of the mansion, they suddenly found the tearing in the 60mm plate. The visible crack divided the plate in half from the thickness direction. The crack started at the depth of 3mm thought NDT detection. The accessories made of the other plates of the same type and batch, were detected the interlayer problem. This quality problem was mainly caused by poor rolling. The welding stress would pull open the interlay, then the tearing from thickness direction may be caused.
Analysis: This kind of accessory due to special position, used as the web in component. The accessories were weld along longitude, while the stiffened plates were full penetration groove force in welding. In addition, there was delimitation inside the plates. So the welding stress tear the plates from the thickness direction.
- It should be the rolling problem, if the most of steel materials were delamination. That was exceeded the relevant national specification standard, the manufacturer should be required to investigate, and those materials should be recalled or be changed.
- If the delamination problem was light, the person in charge may ask for the comment from the technical department and the owner, then feed backed to the manufacturer and required them to take remedies on it. People can take the remedy as follow: find out the defected parts according to NDT; gouge out the defected parts; fill in the welding materials of same strength; take care of the surface at last. The repaired steel materials should be proceed NDT after a specific time, then sampling it to carry physical and chemical inspection. The materials were allow to reuse if they could meet design specification.
- Under the witness of supervisor, slice off the defected plates and change a fine steel plate. The defected plates can be used to non-load-bearing parts and non-critical parts, or be used as the auxiliary. The reused defected plates should be gone through NDT and recorded.
Problems occur in the construction processes
The manufacturing procedure is the procedure which easiest to occur with quality problem and once occur with quality problem in the special procedure and important procedure, it will be quite difficult to handle with.
The general procedures have very low ratio of occurring with quality problem.
On above construction procedures, the special processes are including the soldering and coating, and the important procedures re including the blanking and assembling.
- Welding procedure
This procedure is a kind of hidden process and it is one of the procedures which easiest to occur with quality problem. In 2004, we found the reason why the procedure occurred with quality problem from a company’s product quality report. Firstly, the repair rate of welded joint will higher than 80% because of the bad welding quality. Secondly, because of the misoperation in the last process and the operator’s technical question, the quality problem of welded joint will occupy about 10% and this problem is one of the main problems which will affect the project quality.
So this kind of problem can only test and judge by the professional testing company with professional testing tools. Normally it is divided into slag inclusions, incomplete fusion and blowholes according to the defect in the welded joint.
- Coating procedure
This procedure also belongs to a kind of hidden process as the effect it does to the structure is less than the effect it does to the building function.
This is the procedure which easier arises with quality problem.
The quality problem in the procedure mainly reflected in the following details: The paint film on the component surface fall off with large area or fall off with a part of area. The paint film on the component surface fall off, occupy with sagging phenomenon, not enough thickness of the paint film, uneven distribution of the paint film thickness and big chromatic aberration of the paint film.
- Lofting and procedure
This process is very important for the components processing, its quality will affect the next process directly and even can make all the cutting components become scrap. This kind of situation is very common and always happened, so it is very important to reinforce the quality monitoring in the procedure before the cutting.
The quality problem in the procedure mainly reflected in the following details: the long components and thin panel components will transform a lot in the cutting process.
As the cutting gas or the panel have the problem of horse tooth stripe, knot, the depth of nick exceeds standard caused by the slag inclusions and uneven distribution on the cut surface
If do not consider the shrinkage distortion in the next process, the components which do the gas cutting or saw cutting will cause the sizes exceed standard issue.
Compile the technological document by mistake will cause the whole batch components become scrap. The cutting measures exceed the normative requirement a lot.
- Assembly procedure
This procedure plays an important role in the quality of components processing and its quality has affected a lot by the last procedure, so it is very important to reinforce the procedural monitoring before the assembling.
The quality problem which occurred in this procedure mainly reflected in the following detail: Assemble the components in the wrong location, such as the components should assemble in the 3450mm hole, but assembled in the 4350mm hole by mistake.
Use the components by mistake. It should assemble with 2# component, but they assemble with 3# component by mistake.
Put the components on the correct position but assemble by mistake. Such as the 45mm hole on the board should be outward, but it assembled inward finally.
The fit clearance of the assembly components has exceeded standard and the requirement 3mm in the technical documents.
Some components were assembled without doing any adjustment before, after the assembling, that existing wrong data can’t be deleted.
In order to save time and labor, some operators do the incision privately which will cause the size of hole site exceeds standard, do not do the surface treatment in the assembling and welding area, assemble incorrectly due to the wrong drawing size
- Problems in the usage
Some manufactures used some cheap and non-flameresistant material as the filler to save the cost. The unqualified usage of foam in the steel workshop house will easily outbreak of fire and cause the casualties accident.
- Built-in fitting
Stabilize the structure of the plant
Normally uses H-shape steel or C-shape steel (generally connects two C-shape steel together by the angle steel)
Normally uses C-shape steel and H-shape steel (the height of the middle product will depend by the span of the beam)
Normally uses C-shape steel, but sometimes use box iron also.
There are two types of tiles, one is single ply tile which we called it color steel tile, and the other is composite board which composed of polyphenyl, rock wool and polyurethane.
The foam which filled in the middle of the tiles has the effect that warm in winter and cool in summer
Steel workshop house mainly means that the bearing members of the plant are composed of steel.
Included the steel column, steel beam, steel-structure basis, steel roofing truss (the plant uses more steel, and they use steel structure for the roofing truss), steel roof. And one thing we need to note is that the steel-structure wall can maintain as the same way of brick wall also.
As the Steel output of our country has increased a lot, now many plants start to construction with steel structure. And it can specifically divide into lightweight steel workshop house and heavyweight steel workshop house.
Compared to other material structure, steel-structure has below characteristics:
- Steel workshop house
- High strength and light-weight:
Although the density of steel is higher then other building materials, it has quite high strength. Under the same force conditions, the steel structure has the characteristics of light weight and it can change to be a kind of structure with big span.
- Good plasticity and toughness
The steel has good plasticity and in general the structure won’t break suddenly under the overload or part overload by accident.
The steel has good toughness that makes the structure has stronger adaptation to the dynamic load
The steel has well-distributed internal organization and isotropy.
The practical-working performance of steel structure has high degree of coincidence with the adoptive theoretical results, so the structure has quite high reliability.
As steel has solderability, it can simplify the connection of steel structure and adjust to manufacture various kinds of complicated shape of structure.
High degree of industrialization of the steel-structure fabrication and installation
Steel-structure mainly manufactures in professional metal-structures plant, so it has simple manufacturing process and high accuracy.
And all the finished components will be transported to the site for installing, which can get high degree of assemblage, fast installation speed and short construction period.
As the internal organization of steel is very compact, while using welded connection or even rivet and bolted connection; it can easily make it compactly and do not leak.
- Fire resistance
When the surface temperature on the steel are within 1500℃, the intensity of the steel just change a little, so steel structure is suitable for the hot workshop.
When the surface temperature on the steel exceeds 1500℃, the intensity will decline obviously.
When the surface temperature on the steel achieves 500—600t, the intensity will slow down to be almost zero.
So when the fires are breaking out, the steel structure will collapse suddenly as its fire-resistant time is very short.
For some steel structure which need special requirements, we need to do some measures for thermal insulation and fire-resistant
- Corrosion resistance
Steel is easy to rust in the humid environment, especially in the environment which has corrosive medium. So it needs maintenance routine, which will increase the maintenance charge.
- Construction scheme
Content introduction for the construction scheme of steel workshop house
Installation of steel structure Installation of steel column → Installation of column bracing → steel crane girder temporary is in place → Roof girder and roof support → Adjustment and fixation for the steel crane girder →Installation of the maintenance structure
Installation procedure with diagrammatic sketch as below:
- Installation of steel column
- We can’t manufacture and transport the steel column at one time due to its heavy weight and long length. So we do the fabrication in sections and then assemble them into a whole on site and do the hoisting, finally divides the steel column into two parts to do the manufacture. The steel column has divided into two parts which are bottom lattice part and upper part with H shape steel column to transport to the site. The weight of the steel column is about 6 tons and the height is about 17 meters, which need a 50 tons truck crane and assists by a 25 tons truck crane in the meantime to do the hoisting.
- The hoisting uses one machine to do the rotational slinging.
Before the slinging, we need to pad the batten under the heel slab of the steel column to avoid any damage to the heel slab in the slinging process.
While slinging the steel column, the crane needs to rise up the hook and turn arm at the same time to lift up the steel column vertically and put the column into the hole.
- Daily maintenance and service
After the steel workshop house is installed, the owner shouldn’t change its structure privately, shouldn’t disassemble any components, such as the bolt, shouldn’t add or reduce the partition wall. If they need to change any part of the steel workshop house, they should consult with the manufacture and the manufacture will estimate whether they can do the change or not.
The steel structure must do the paint maintaining one time after 3 years usage to make the construction more beautiful and safe.
The steel workshop house is connected by the steel-structure components, while using the electrical equipment, such as thIts advantage goes without saying, such as Its advantage goes without saying, such ase electric wire, we need to use the trunking and spool to do the isolation to avoid any electric shock accident.
The steel workshop house must be cleaned and maintained at regular intervals, normally it needs to do one inspection and maintenance per year.
While washing the outer wall of the steel workshop house, pls make sure to avoid any disordered phenomenon. Don’t use any cleaning product which has abrasive effect, such as steel wire ball and scrubbing brush and use the clean water to clear and wash from top to the bottom.
If there are any objects such as tree branches or leaves fall on the steel workshop house, they should be removed and cleaned in time to avoid any trouble which cause by overstock.
If you find any damage on the metal surface of the steel workshop house, you need to repair it in time to avoid the metal board corroded by sun-scorched and rain-drenched.
Use the high elasticity nanometer materials to do the whole painting, it can protect the metal board on the roofing and do the heat insulation and waterproof effectively to save the air-condition energy indoor.
The service life of steel-structure depends on the maintaining of steel workshop house, so the owners should pay enough attention to the maintaining.
If you meet any problem in maintaining, you should contact the professional steel workshop house manufacture and ask for help.
Advantage of steel workshop house
Everyone’s life is closed related with the nature. We need to live in harmony with the nature so that we can get a glorious future. The steel structure has combined with these characteristics and makes a very big contribution to the construction industry. It not only beautifies the environment, but also firms the house.
It is the safeguard for people’s lives and property. The steel-structure house indeed can do the combination with nature.
After the WenChuan earthquake, people’s understandings for the safety of house and the earthquake resistance of environmental factor have increased substantially.
The environmental problem and housing problem have closely connection and they are inseparable. We need to safeguard the safety of house and also safeguard not to do any bad influence to the environment in the meantime. Living in harmony with the nature, this is the mission which needs to be shouldered by structural steel construction.
Environmental problem is the source of all things. Steel-structure house has so many advantages, which is the reason why it is so popular nowadays. Steel-structure house is a kind of housing construction with load-bearing beam column.
Its advantage goes without saying, such as:
- As the steel structural members manufacture in factory, which can reduce the workload on site, shorten the construction period, accord with the requirement of the industrialization. It not only can save the resource, but also can reduce some unnecessary pollution.
- The reliable manufacture quality, precise measure and easy installation of the steel workshop house can help to make it easy to cooperate with other related parts.
- Because of the light weight and high strength, the weight of steel-structure house only one second of the reinforced concrete house.
- The steel can be recycled so that it will reduce the environmental pollution in construction and dismantlement.
- The steel-structure house has the characteristics of safe and good reliability, good seismic resistance, good wind-resistant performance and strong load capacity. Its shock resistance can achieve 8 classes and won’t collapse in the strong earthquake and won’t be damage in the middle earthquake.
Consider people first and then combined with the nature. This is the value of the steel-structure house. For the building houses, guarantee the people’s safety is the most important thing. Such as Tangshan earthquake, WenChuan earthquake and Ya ' an earthquake, all of these earthquakes have brought people unforgettable hurt and injure.
Matters need attention:
- Design attention to the roofing of steel workshop house
- Anti-seepage performance: Prevent the rainwater from seeping into the metal roofing board from outside.
- The rainwater mainly seeps into the metal roofing board by the lapped joint.
- In order to meet the seepage-proofing requirement, we need to use the sealing washer on the bolt to do the concealed fastening. Use the sealant or soldering to seal the joint, it can be better if we can use the long panel to avoid the joint and then do the seepage-proofing process on each joint.
- Fireproofing: Once the fire break out, it can’t burn the metal roof material and the flame can’t get through the metal roofing board.
- Wind pressure resistance: Resist the biggest wind pressure in local and make sure the metal roofing board won’t be taken off by the negative wind pressure.
- Wind-resistant performance has related with the resultant between metal roof board and permanent seat and the density of the permanent seat.
- Sound insulation: Prevent the sound comes from outdoor to indoor, or comes from indoor to outdoor.
- Filling the metal roof with sound-proof material (use heat preservation cotton always), sound insulation effect shows by the sound intensity difference which comes from two flanks of the metal roofing.
- The effect of sound insulation is related to the density and thickness of the sound-proof material.
- Need to pay attention that the sound-proof material has different effect to different sound frequency.
- Ventilation: Do the interchange of air indoor and outdoor.
- Installing the ventilation opening on the metal roof.
- Dampproofing: Prevent water vapour from condensing on the bottom layer and surface of the metal roofing board, and drain the water vapour from the surface of the metal roofing board.
- The solution is filled the metal roof board with heat preservation cotton and put the waterproof membrane on the metal roof board. There are some ventilated panel points on the metal roof board.
- Load-bearing: It can bear construction load, rainwater load, dust load, crushing load by snow, maintain load.
- The load-bearing performance of metal roofing board has related with the cross-section characteristic of the board, the strength and thickness of the material, the way of force transfer, the space between the purline (or subpurlin).
- Thunder prevention:: Guide the thunder to ground to avoid any situation that the thunder punctures the metal roofing board and enters the indoor.
- Heat preservation: Preventing the heat transfer on the two flanks of the metal roofing board to make a stabilized temperature indoor.
- The heat preservation function was achieved by the heat preservation materials (we always use glass wool or rock wool) which are filled under the metal roofing board. And the heat preservation effect denoted by U value and the unit is W/M2K.
- The thermal insulation property depends on following factors: Raw material, density, thickness, the humidness of heat preservation cotton and the connection way between the metal roofing board and understructure (should prevent the cold bridge phenomenon)
- The metal roof surface has the repeat absorb ability to the thermal radiation.
- Daylighting: Improve the indoor illumination in daytime by skylight so that it can save energy.
- While adding the daylighting panels or daylighting glass on the specific location of the metal roofing board, we should consider the coordination of the service life of skylight and the metal roofing board, and then do a good waterproofing process on the joint which is between the skylight and the metal roofing board.
- Blazonry: The surface of the metal roofing board has good texture and nice color.
- The controlling of heat expansion and cold contraction: Control the displacement and direction of the metal roofing board, which caused by the shrink.
- Making sure the metal roofing board won’t be damaged by the heat expansion and cold contraction in some area which has large temperature difference.
- Avalanche prevention: Install handrail on the metal roof board in the snowfall area to prevent the accumulated snow from creeping down suddenly.
- Icicle prevention: Preventing the snow from forming icicle on the cornice.