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Shenzhen Convention and Exhibition Centre, the stone coated metal roof system de

 Published:2011-10-22 12:48:11    Source:    Views:745

Shenzhen Convention and Exhibition Centre, the stone coated metal roof system design and construction (2) 
  
  
 
Shenzhen Fangda Decoration Engineering Co., Ltd. Ye Zhiqing

1.4 panel layer include: aluminum panel, aluminum alloy bearings, insulation isolation pads, screws, etc.
A) aluminum panel
Aluminum roof panel is the primary water barrier system, international and domestic uses is more popular is the dark button standing seam aluminum-Mn-Mg alloy plate roof system, which has the following characteristics:
a) have the overall structural waterproofing, drainage;
b) structure is simple, lightweight, safe, marine typhoon, heavy rain areas, especially applicable;
c) construction and installation of flexible and fast.
Aluminum panels on the one hand the system to fully ensure the functional requirements waterproof, the other to satisfy the safe, reliable and anti-corrosion requirements, designed to take strength and good corrosion resistance magnesium manganese alloy plate ( Alloy state of H44, alloy composition of AA3004, the yield strength ≥ 150 MPa, tensile strength ≥ 180 MPa, elongation of metal ≥ 4%, surface treatment for the pre-roll coating of fluorocarbon paint surface), and because the panel is thin for 1.0 mm magnesium manganese sewing-pressure level board, so that the system design side stand 65 mm high setting, can have a stronger overall panel strength and stiffness; in the middle of the plate spacing of 100 mm along the longitudinal arrangement of the small arc-shaped ribs and allows panels to obtain sufficient local stiffness will enable the panel to meet in a variety of working conditions of the application (see Figure 8). Installation of aluminum roof stitching, sewing through the strong electric sewing machine quick suture, while male and female side of the merger closely link bracket tightly. As the high rib roof, rain will not diffuse through the roof and flooding, due to capillary phenomenon may occur along the flooded rib plate on top of one side of the public were without water lines cut off, the rain will not dip into the house panel, with very favorable waterproof performance. Suture to complete the roof, the roof is not exposed screws, plate ribs smooth smoother, and have sufficient strength to withstand pedestrian and other dynamic load on the roof. Under the roof filled with polystyrene insulation board is full, so that the whole roof is more flat solid.
B) bearing
Bearing aluminum alloy bearings (see Figure 9), the use of high strength and hardness of 6063-T5 aluminum alloy, bearing the shape of an inverted T-like, it is also known as "T" code. The edges of adjacent panels overlap the top and hold in the bearing edge and bite through the machine fixed to the bearing, so that the panel can only slide along the bearing or bearings turn around to meet the temperature difference caused by stretching as required. As the panel and the bearing are frequent relative motion, so the bearing of the arc-shaped top designed to prevent the panel in the sliding bearings when scratched. The bottom bearing of 6 mm thick plate, set aside a screw hole spacing, and bearing the number of screws to be based on the structure calculation.
C) insulation isolation pads
Insulating gasket of sufficient strength and the use of anti-aging properties of poly amide material, on the one hand to prevent direct contact with aluminum bearing steel purlins electrochemical corrosion resulting from the other hand, can effectively reduce the roof's thermal conductivity and noise (see Figure 10) .
D) Tighten the screws
To minimize the difference between the electrochemical metal corrosion and ease of site installation, the fastening screws of stainless steel self drilling screws, screw size and number to be determined according to the structure calculations (see Figure 10).
(2) the calculation of stone coated metal roofing  system:
The calculation of stone coated steel roofing  system engineering including structural calculations, thermal noise calculation and the calculation of the drainage system.
2.1 structure calculation
The project design is based on probability theory-based limit state design method to design, structure importance coefficient of 1.1, seismic intensity of 7 degrees, the design life of 50 years.
A) panel level check
a) checking the roof: roof span of 1.5m under the most unfavorable load taken by other cross-check the calculation of continuous beam strength and stiffness of the roof. The roof project parameters as follows:
b) aluminum bearing checking: According to the calculated reaction force continuous beam bearing on the strength of aluminum alloy for checking.
c) connecting bolt check: According to the calculated continuous beam reaction force on the connecting bolts of tensile and shear strength of the check, to determine the number and size of bolts used.
B) structural purlins layer check
a) structural purlins check: structural purlins span by taking the most unfavorable load simply supported at both ends of the structure of the calculation of checking the strength and stiffness of purlins.
b) connecting bolt check: According to the calculation of a simple beam reaction force on the connecting bolts of tensile and shear strength of the check.
C) layer of pressure-plate check
a) pressure-plate of the check: press-shaped plate to take the most unfavorable load span simply supported at both ends of the calculation method of checking the pressure-plate strength and stiffness.
b) connecting bolt check: According to the calculation of a simple beam reaction force on the connecting bolts of tensile and shear strength of the check.
D) checking drains bracket
Gutter bracket span by taking the most unfavorable load clamped at both ends of the gutter bracket checking the calculation of the strength and stiffness, and according to their way of connecting with the main (bolted or welded connections) to check the reliability of connection .
2.2 acoustic insulation calculation
According to the parameters used in insulation materials for heat transfer calculation to determine if the meet the requirements.
2.3 drainage system to calculate the
The location of the project according to meteorological data and calculated according to the actual situation of the roof of the roof catchment area to calculate the stormwater drainage system to determine the bucket of each model, the number of rain bucket.
3 metal roof lightning protection system design:
Mine is a basic building safety requirements, but also the basic requirements for roofing system. Practice is usually roof lightning protection lightning protection zone for surface and roof lightning protection network, this method is not very beautiful. The metal roofing system in this project because of the stone coated steel roof is a good conductor, the following is non-combustible material insulation materials, according to the "building lightning protection design specifications" (GBJ57-2004) 4.1.4 of the metal plate under the non-flammable, board ≥ 0.5 mm thick, the roof can be used as air terminals (except the first class of mine buildings), so the only reasonable arrangements can lead to the next point of the metal roof lightning protection requirements.
Specific design is to insulate the aluminum bearing the following into the aluminum gasket replacement gasket to form under the points lead mine, the formation of metal roofing aluminum gasket → → → aluminum bearing steel steel roof purlins → conduction circuit, and the building of lightning formation of electrical Unicom network, so as to achieve the purpose of lightning protection. Cited under the arrangement of every point of a 8 m, then the two ends of the roof for each one, to ensure the reliability of lightning protection and grounding.
Third, the construction of stone coated steel roofing systems:
1 Water resistance:
Waterproof roofing system is the most important function, as the engineering design of the roof is no vertical seams, the roof and roof drainage along the longitudinal direction of laying, as long as the proper handling of nodes and roof cornices and roof drains phase transition of the node, you can prevent the occurrence of leakage. As the roof and skylights of the interface are more prone to water hazards handled in this project will raise the roof, making it stand above the roof edge, roof thrown in with the roof shut at a certain height, can be prevent water intrusion, so as to achieve the purpose of water. And in the roof and the insulation board is located between a PVC waterproofing membrane, that is, double waterproof, so that local leaching may be a small collection of PVC waterproofing membrane into the gutter.
(2) drainage:
Smooth stone coated steel roof drainage system, not only conducive to waterproof the roof, and roof water can be avoided as a result of the additional load on the structure of the roof system have an adverse impact.
The roof drainage project implementation mainly through the drains and drainage pipes to set a reasonable, effective organization of rain emissions, in order to ensure smooth drainage channel. The location of drains and drainage pipes and the number should be the size of the roof, to match the slope direction, drains, sink width and depth consistent with the roofing system, and have the appropriate anti-structure, temperature deformation capacity.
The project mainly by the stainless steel panel tank drains, structural joist (interval arrangement, the need to ensure drains should bear the load and maintenance of security Exalted), insulation (extruded polystyrene foam board) and composition (see Figure 11). Stainless steel box beam side of the roof gutter trough lower than 50 mm, and stainless steel gutter and horizontal welding, with overflow discharge and to avoid special cases, horizontal rain swept over the roof gutter. Set aside in the drainage hole on the left to install rainwater hoppers and drains, water bucket size and the number are based on calculations to determine the base for the water bucket made of stainless steel, welded directly to the gutter panel assembly to ensure waterproof and reliable.
3 thermal insulation function:
Purlins in the roof and structure between the laying of extruded polystyrene foam boards are able to effectively meet the roof insulation system functions, the board has the following characteristics:
1) Light: extruded polystyrene foam board extrusion process in a continuous and uniform surface and obturator-type honeycomb structure, the honeycomb structure forming a small hole bubble in the middle of the air will not flow.
2) Low water absorption: the bubble does not make plates with excellent water absorption.
3) excellent thermal insulation properties.
4) compressive strength Compressive strength: the ability to walk to meet the construction requirements of the Master.
5) Fire and ability to meet the building's fire safety requirements, to achieve flame B2 level.
6) start the edge of the mouth plate, you can stagger the lap laid, effectively prevent the formation of cold bridges.
4 acoustic noise reduction:
Laying on the pressure plate-shaped sound-absorbing cotton and pressure plate-shaped openings on the principle to the use of micro-acoustic sound absorption, sound insulation to meet roof system noise reduction.
Ultra-fine glass wool sound-absorbing cotton, which is characterized as follows:
1) chemical stability, no other structural features corrosion layer;
2) No slag wool ball and foundation dust, reducing the health impacts of construction workers;
3) uniform, thin and large quantities of glass fiber products in the air produced a great deal of viscous resistance, the complete elimination of air convection thermal conductivity, while the surface layer of aluminum foil insulation to reduce radiant heat also played;
4) is non-combustible glass wool products, meet Class A fire;
5 lighting functions:
The light roof systems engineering function to achieve mainly through the glass roof and opening roof skylights to achieve one hundred, of which the design should take into account the roof exhaust and ventilation functions.
6 mine-protected.
Fourth, the process works
1 processing of stone coated steel roofing 1) steel processing
Metal roofing steel (structural purlins and pressure-plate, etc.) to be processed in the factory, to ensure good precision.
2) The roof of the processing
Standing seam roof a dark button-Mn-Mg aluminum alloy plate processing by-site roll forming rolling processing center, the processing steps are as follows:
A) Equipment in place: aluminum alloy plate processing equipment can be winched to the roof level height, plate after molding process can be laid directly in accelerating progress while reducing the material stack space and transportation.
B) Equipment debug: processing equipment, hoisting, the process must be adjusted to the requirements under the plate position and solid lifting. Three days before the start of commissioning and trial production equipment, adjusting the parameters until the device can produce qualified panel.
C) on the material: raw material for aluminum production roof volumes, each volume weighing about 2 tons, through the lifting equipment will be sent to the volume of aluminum processing equipment. Aluminum coils should be stacked in the overhead rack, ventilated and dry to avoid moisture affecting the surface quality of aluminum volume.
D) plate forming: processing equipment with the direction of the plate roller bracket, about 10 meters, when squeezed out of the roof more than 10 meters must be carried by hand to move forward to live until the house long enough to produce panel. When designing the length of the roof length, the stop plate and cutting, cutting the length should be slightly longer than the design length 100 mm, to facilitate the future end of the cutting board.
(2) the installation of stone coated metal roofing Metal roofing installation required size of the main steel structure retest, if the structure size deviations beyond the scope of allowable error must be adjusted, otherwise it will affect the appearance and free of retractable stone coated metal roof.
The project's roofing system -stone coated metal roofing installation and construction flow chart are as follows:
V. Conclusion
With the country's rapid economic development, the demand for high-performance roofing systems will become increasingly large, and Al-Mn-Mg alloy roofing system with its superior fire protection, thermal insulation, noise, lightning and other functions in high-performance roofing system. occupies an important position, and its system with its own technology more widely and apace.
References
[1] roofing project technical specifications (GB50345-2004) Beijing 2004.
[2] building lightning protection design specifications (GBJ57-2004) Beijing 2004.
[3] Steel Construction Quality Acceptance (GB50205-2001) Beijing 2002.
[4] structural load standard (GB50009-2001) Beijing 2002.
......

edited by  stone coated steel roof

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