Do you really understand the construction technology of curtain wall engineering
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1. Making and
Installation of Embedded Parts of Building Curtain Wall
1) Technical
Requirements for Manufacturing Embedded Parts
(1)
Processing Requirements for Flat Embedded Parts
(1) Q235
grade steel should be used for anchor plate, HPB35, HRB335 or HRB400 grade
hot-rolled steel bars should be used for anchor bars, and cold-processed steel
bars should be strictly prohibited.
(2) Effective
anticorrosion treatment should be adopted for embedded parts.
(2) Technical
Requirements for Installation of Embedded Parts
(1) The
embedded parts should be laid in accordance with the position and
specifications of the design requirements when pouring tamping concrete into
the main structure.
(2) In order
to ensure the reliability of the links between the embedded parts and the main
structure, the strength grade of the main structure concrete at the links
should not be lower than C20.
(3)
Preventing the displacement of embedded parts during pouring and tamping of
concrete
When curtain
wall is connected with masonry structure, reinforced concrete or steel beam or
column should be added to the main structure of the connecting part. Light
filling should not be used as supporting structure of curtain wall.
(3) Glass
curtain wall supported by frame (open frame, concealed frame and semi-concealed
frame)
1) Manufacture
of Frame Supported Glass Curtain Wall Components
The glass
plate making of semi-concealed frame and concealed frame glass curtain wall is
a key work to ensure the engineering quality of glass curtain wall, and the
cleaning of glass panels and aluminium frames before injection is an important
process related to the quality of glass plate processing. Cleaning work should
be carried out by "twice wiping" process. Glass panels and aluminium
frames should be injected with glue within 1 hour after cleaning, and
re-cleaning should be done when there is serious pollution before gelling.
(2) Qualified
compatibility test report must be obtained before silicone structural sealant
is injected, and primer should be applied if necessary. No expired sealant
shall be used.
(3) Glass
plates should be injected with glue in clean and ventilated rooms. Indoor
environmental temperature and humidity conditions should meet the requirements
of structural rubber products. Indoor cleanliness is required. The temperature
should be between 15 - 30 C and the relative humidity should be above 50%.
After plate
processing is completed, it should be maintained in a clean room with
temperature of 20 C and humidity of more than 50%. The curing time of
one-component silicone structural sealant is generally 14-21 days, and that of
double-rent silicone structural sealant is 7-10 days.
When making
glass plate, we should correctly grasp the orientation of glass. The coated
surface of single coated glass should generally face to the indoor side, and
the coated surface of sunlight-controlled coated hollow glass should face to
the air layer.
2)
Installation of frame supported glass curtain wall
(1) Column
installation
Aluminum
alloy columns should generally be designed as tension members, the upper supporting
point should be circular holes, the lower supporting point should be long
circular holes, forming the suspension stress state. Between the upper and
lower pillars, closed profiles can be connected by core pillars of length not
less than 250mm, which should be closely matched with the pillars, and open
profiles can be mechanically connected by equal strength profiles.
The cracks
between the upper and lower columns should be no less than 15 mm, and the
silicone weatherproof sealant sealant should be injected to seal. In addition
to stainless steel, flexible gaskets should be preserved and isolated between
the contact surfaces of two different metals in order to prevent bimetallic
corrosion.
(2) Beam
Installation
When the span
of aluminium profile beam is not more than 1.2m, the thickness of the main
stress parts of the section should not be less than 2.0mm; when the span of
aluminium profile beam is more than 1.2m, the thickness of the main stress
parts of the section should not be less than 2.5mm, which is generally
connected with the column in segments.
Connecting
fasteners between beams and columns shall be connected by stainless steel bolts
and bolts according to design requirements. In order to adapt to thermal
expansion and shrinkage and prevent friction noise, rigid contact should be
avoided at the connection between the beam and the column. Flexible gaskets can
be set or 1-2 mm gap can be reserved, and glue is added into the gap. When the
glass curtain wall with concealed frame is connected with fixed glass
components by hooks, flexible gaskets should be set on the contact surface of
the hooks.
(3)
Installation of glass panel
(1)
Installation of semi-concealed frame, glass plate of concealed frame glass
curtain wall, fixed point spacing should not be greater than 300 mm, and
self-tapping screw should not be used to fix glass plate.
(2) Glass
panels of concealed frame and transverse semi-concealed frame glass curtain
walls rely on seams to bear the weight of glass, while silicone structural
sealant bears very low capacity of permanent load, so two aluminium alloy and
stainless steel brackets should be installed at the bottom of each glass.
(3) The
opening angle of the glass curtain wall should not be greater than 30 degrees,
and the opening distance should not be greater than 300 mm. The cracks around
the opening window should be sealed with chloroprene rubber, ethylene propylene
diene rubber or silicone rubber seals.
(4) Sealant
seam
The
construction thickness of sealant should be greater than 3.5 mm, generally
controlled within 4.5 mm.
(2) Sealant
should be bonded on both sides of the joint, not on three sides.
It is not
suitable for gluing at night or in rainy days; the gluing temperature should
meet the actual requirements and product requirements.
4. It is
strictly forbidden to use expired sealants; silicone structural sealants are
not suitable for use as silicone weatherproof sealants, and they can not be
replaced each other.
(5) All-glass
wall
(1) The glass
thickness of all-glass wall panel should not be less than 10 mm; the thickness
of laminated glass should not be less than 8 mm; the cross-section thickness of
glass ribs should not be less than 12 mm, and the cross-section height should
not be less than 100 mm.
(2) The size
of glass panels for all-glass walls is generally large, so mechanical suckers
should be used to install them.
(3) The loads
and functions of all-glass wall panels are transmitted to glass ribs through
seams, which must be made of silicone sealant. The thickness of the seam shall
be determined by design calculation. The size of the seam must be guaranteed in
construction and the bearing capacity of the seam must not be weakened.
(4) Silicone
structural sealant is allowed to be injected into the whole glass wall on site.
Because the
acid silicone structural sealant corrodes the film of various coated glass, the
sandwich material of laminated glass and the joint of hollow glass, the acid
silicone structural sealant and acid silicone weather-resistant sealant sealant
sealant can not be used in all glass walls of the above glass.
The panels of
all glass walls shall not be in direct contact with other rigid materials. The
gap between the panel and decoration or structural plane should not be less
than 8mm, and should be sealed with sealant.
(6) Fire
protection construction requirements of building curtain wall
(1) The gap
between curtain wall and the outer edge of each floor and partition wall should
be sealed with non-flammable or non-flammable materials. Rock wool or mineral
wool can be used as filling materials. Its thickness should not be less than
100 mm, and the fire resistance limit requirements should be met. Fire-proof
smoke belts should be formed between floors and rooms.
The fire
protection layer shall be supported by galvanized steel plate with thickness
not less than 1.5mm, and shall not be supported by aluminium plate. The gap
between the supporting plate and the main structure, curtain wall structure and
supporting plate shall be sealed with fire-proof sealant, and the fire-proof
sealant shall be reported by the legal inspection institution.
(2) Curtain
walls without windowsills should be equipped with non-combustible solid skirt
walls or firewalls with fire resistance limit not less than 1.0h and height not
less than 0.8m at the outer edge of each floor. When calculating the height of
skirt wall, the thickness of reinforced concrete floor or the height of side
beam can be taken into account.
(3) Fireproof
layer should not be in direct contact with curtain wall glass.
(7) Lightning
protection construction requirements of building curtain wall
The metal
frame of curtain wall should be reliably connected with the lightning
protection system of the main structure.
(2) For
aluminium alloy pillars of curtain wall, a flexible conductor should be used to
connect each upper and lower pillar within the range of not more than 10m.
(3) The
curtain wall roof plate with lightning protection function should be made of
aluminium alloy plate with thickness not less than 3 mm, which should be
effectively connected with the lightning protection system of the main
structure roof.
(4) Lightning
protection connection should be carried out on components with coated layer.
(8) Sealing
structure of curtain wall
The sealing
structure of curtain wall should be constructed according to the design
drawings.
(2) Bottom
sealing: There should be expansion gap between the column, bottom cross beam
and glass plate and the main structure, and the width of the gap should not be
less than 15 mm.
(3) The
pressure gradient of the top-sealing daughter wall should meet the design
requirements. The inner cover of the daughter wall should not be less than 150
mm. The daughter wall of the metal curtain wall should be made of single-layer
aluminium plate or stainless steel plate to form an inclined top.
(4) The gap
between the surrounding sealing curtain wall and the main structure should be
tightly filled with fire-proof and thermal insulation materials. Cement mortar
should not be directly contacted with aluminium profiles, and dry and hard
materials should not be used for filling.
The glass
should not be directly contacted with other rigid materials. The gap between
the glass periphery and the decorations inside and outside the building should
not be less than 5 mm; the gap between the panels of all glass curtain wall and
the decoration or structural plane should not be less than 8 mm.