Glass panel design for skyscrapers glass facade

 The application of architectural curtain wall began at the end of the 19th century, when it was only used for a small part of the building. By the 1950s, with the development of construction technology, glass curtain walls began to be applied to the building envelope on a large scale, By the 1980s, with the development of building curtain wall technology and glass production technology and processing technology, glass curtain walls have been more widely used.

The total amount of China curtain walls in existing buildings exceeds 1 billion square meters, glass facade account over 50%,most of them are used in skyscrapers.Here we introduce the glass panels designs for skyscrapers.

glass curtain wall in modern city-China morn glass

 

Why glass is the most important curtain wall materials in Skyscrapers?

As a building material, glass has four major characteristics at the same time: transparency, high strength, light weight, and durability.

Materials	Transparency	Strength	Light Weight	Durability
Glass	Yes	Yes	Yes	Yes
Steel panels	NO	Yes	Yes	Yes
Aluminium Panels/Zinc Panels	NO	NO	Yes	Yes
Concrete	NO	NO	NO	Yes
Bricks,Stones	NO	NO	NO	Yes
Polycarbonate	Yes	NO	Yes	NO
ETFE	Diffused	NO	Yes	NO

Glass Light transparency

Glass is a transparent material. The visible light transmittance of clear float glass is 85-89%. Low iron glass reduces the iron element in the glass, making it more crystal clear and translucent, and the visible light transmittance is increased to more than 90%.

Glass application in buildings

The light transmittance of polycarbonate board (PVC board) can reach 75%~80%.

Thin film materials (such as ETFE) can only transmit diffused light, but are opaque.

Glass Strength

Glass is a brittle material, but has high tensile strength. Among the commonly used wall materials, its tensile strength is second only to steel and much higher than other materials.

Materials	Tensile Strength (N/MM2)	Density (KGS/M3)
Float glass	50	25.6
Tempered Glass	180	25.6
Steel	235	78.5
Aluminium profiles	108	27.1
Concrete	2-3	25

Glass light weight

The glass bending strength is very high, especially the tempered glass plate. Therefore, the glass panel of the glass curtain wall is very thin,. Even if insulating glass or laminated insulating glass composing of 2 or 3 layers of glass, unit weight is only 40 ~ 80Kg/m2, which is much smaller than the 350 ~ 500kgs/m2 of the concrete wall /㎡.

The glass curtain wall weight is about 1/100 of the building total weight. This creates the necessary conditions for the upward extension of the building height.

glass curtain wall system has light weight

Due to its high weight and low strength, stone curtain walls are rarely used in buildings above 400m. Similarly, for skyscrapers above 400m, architects will not choose to use sheet metal due to the requirements of architectural art functions. Above 500m, almost all glass curtain walls. Without glass curtain walls, there would be no super-tall skyscrapers above 500m.

Glass panel designs for skyscraper

1. Low iron Glass

Tempered glass has the possibility of spontaneous explosion. Skyscraper glass facade will bring a great risk of spontaneous explosion,and it is extremely difficult to replace the glass after glass breakage. Therefore, effective measures must be taken,including:

glass spontaneous breakage replacement-glass curtain wall

1. Heat strengthened glass.Surface strength is lower than tempered glass,no breakage possibility.
2. Low iron glasswith lower iron content. During production, nickel and nickel sulfide content is also decrease.. The spontaneous explosion rate of ultra-white glass after tempering can be reduced to 0.0001, or even lower.

Even though low iron glass is 30% higher than clear glass,considering the decreased future replacing costs,it’s worthwhile to use low iron one to decrease overall costs.

China low iron glass-ultra glass supplier

 

2. SGP laminated glass

PVB laminated glass is currently the most widely used glass in curtain wall.While PVB was It was originally developed for automotive glass, not for architectural curtain walls, so it is elastic, relatively soft, and has small shear modulus. PVB laminated glass has small bearing capability and large bending deformation.

Meanwhile the exposed edges of PVB laminated glass are easy to delaminated, after years ,glass will become yellow color.

laminated glass-delamination-glass quality problem

For skyscraper glass,the interlayer should have below characteristics:

1. High bonding strength,high shearing modulus.
2. High protection capability against hurricane,earthquake,thefts, and sudden impact to avoid collapse.
3. High sustain capability after glass breakage.
4. No color change after years.

SentryGlas Plus was invented to fulfill the high structural laminated glass requirement in skyscraper glass facade,large span skylight,oversized laminated glass and all glass structural buildings.

SGP laminated glass installation

 

Features of SGP laminated glass:

A.High bearing capability,smaller bending deflection：

The shear modulus of SGP is more than 50 times that of PVB, and the tear strength is 5 times higher than that of PVB.The bearing capacity is twice that of PVB laminated glass of equal thickness,meanwhile under the equal load and thickness, the bending deflection of SGP laminated glass is only 1/4 of that of PVB laminated glass.

B.Excellent edge stability

Edge stability refers to the laminated glass edges durability exposed to atmospheric conditions. PVB glass is not resistant to moisture, it is easy to delaminate under water vapor. The SGP film is not sensitive to moisture, and will not open or separate when used under exposed conditions.So SGP laminated glass is conveniently used for glass railings, canopy, glass fins and other exposed edge components without special edge sealing measures.

C.High sustain capability after breakage

Once tempered laminated glass is broken, it will be bent and deformed causing the falling off or collapsing dangers. The risk is greater when the glass is installed horizontally on the skylight.

The SGP interlayer laminated glass has good integrity.The SGP film can bond the broken glass to form a temporary structure after damage. The deformation is small, and it can withstand a certain amount of load and prevent falling.More details:

Post Breakage Strength Testing for Overhead Laminated Glass

SGP laminated glass bridge-breakage test

 

3. High performance low-E coating insulated glass.

With the development of glass technology,energy-saving is becoming more and more important,especially for skyscrapers with thousands square meters glass curtain wall,the energy used for heating and cooling is awesome.

Clear float glass U value is 5.8w/m2.k,with new double silver low-E coating and triple silver low-E coating,double glazed units U value can be decreased to 1.5-1.6W/M2.K,with more energy saving measurement,such as filling argon into the insulated glass,and warm edge spacer to decrease the thermal conductivity ,glass U value can be decreased to only 1.1-1.2W/M2.K,which contribute to the overall thermal insulation performance of the glass facade.

Thermal-insulation-glass

Function of Low-E coatings:

The low emissivity coating can reflect the far infrared radiation directly,especially the silver layer inside the soft coated low-E coating can reflect 98% far infrared radiation like mirrors.

The coating has little capability absorbing the heat,which will control the glass surface temperature very well, the heat re-radiated out from the glass is little accordingly.

Despite controlling the infrared,the coating as a variety options with different visible light transmittance and SC value(0.2-0.7)  to control the ratio of direct solar energy transmitted through the glass,which can be selected by users both in hot and cold areas.

low-E coated insulated glass in glass facade

 

For more details,please check our previous posts:

20 FAQ about low emissivity glass-Glass Guidance

Triple silver low-E insulating glass in LEED buildings

Difference between Single silver low-E,double silver low e and triple silver low e

Insulated glass-feature,thermal performance&calculation tool

Conclusions:

1. skyscrapers above 500m in height always use glass curtain walls,including stick curtain wall,unitized curtain wall.
2. Double laminated insulated glass,or laminated insulated glass are priority for skyscrapers.Glass can be heat strengthened ,or low iron glass to decrease glass spontaneous breakage ratio.
3. SGP interlayer is should be considered for the middle layer film. To improve the safety of the glass curtain wall.
4. High performance low-E coatings-double silver low-E,triple silver low-E coatings are applied in the insulated glass to increase facade thermal insulation performance.

Case study:

1. CITIC-BEIJING

Located in Beijing, China CITIC is the world’s tallest building with 8 degrees of seismic fortification, with 108 floors above ground and a height of 528m (Figure 48). The stick curtain wall, the glass configuration is tempered low iron glass with double silver low-E coating + SGP laminated+insulated glass.

CITIC-CHINA SKYSCRAPER-GLASS CURTAIN WALL

2. Tianjin 117 tower

Tianjin Gaoyin 117 has a height of 592m and 117 floors. The 32, 63, 94 and 115~116 floors are high-rise lobbies, with a diamond-shaped glass roof on the top.

The curtain wall has a total area of 147,000 square meters composed with 20,000 unit. The standard unitized curtain wall unit is 4.3m X 1.5m, with 14,000 unit panels;

Glass curtain wall: (8mm+1.52PVB+8mm)+ 12A + 8mm low iron tempered PVB laminated glass.

High-altitude lobby: (8mm+1.52PVB+8mm)+ 12A + 12mm / 10mm low iron tempered PVB laminated glass.

tianjin 117 tower

 

3. Guangzhou tower.

The height of the Guangzhou Tower is 600m, and the height of the glass curtain wall is 460m .The stick glass curtain wall adopts triangular unit panels with a size of 1500mm X 3500mm. Double laminated semi-tempered insulating glass, (8mm+1.52mmSGP+8mm)+12mmA+(8mm+1.52mmSGP+8mm)

guangzhou tower-glass facade

Morn is your turnkey glass manufacturer and supplier in China,we manufacture low iron SGP laminated insulated glass for global projects,welcome contact us for more info.

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Protect your house with hurricane proof glass-Laminated Glass

 

Hurricane proof glass & windows background

Hurricanes are getting stronger and stronger. According to the National Aeronautics and Space Administration (NASA), studies have shown that compared with 20-25 years ago, the wind speed of hurricanes has increased by 5%, which entrained more water vapor.

At the same time, on coastlines prone to hurricanes, both population and property values are rising-this will make costly natural disasters more frequent. In the United States alone, there was a loss of 15 billion U.S. dollars in 2016; in 1980, this figure was only 300 million U.S. dollars (inflation-adjusted figure).

After gaining attention after Hurricane Andrew destroyed the southeastern United States in 1992,Florida law finally stipulates that any house built after 2001 should be constructed with hurricane-resistant windows or hurricane proof shutters.Miami-Dade certificate was also launched to prove the windows&glass rationality in Dade county.

hurricane in USA

How the hurricane cause damages to your house?

The hurricane can cause damages through 2 ways:

1. The hurricane can be classified into 5 levels:

Level 1: 119-153km/h

Level 2: 154-177km/h

Level 3: 178-209km/h

Level 4: 210-249km/h

Level 5: >249km/h

The hurricane always brings huge wind speed and wind pressure,which rip shingles, boards and insulation off roofs, quickly exposing your home to the elements,beside that,everything that exposed outside can be involved in the wind and hit the glass.

hurricane destroy glass-morn

Once the glass broken,the glass fragments become projectiles that can hurt people in the vicinity.

2. Damages after the windows pull out or falling down.

Not only the glass fragments after broken,if the windows frame is not strong enough,the windows itself can be ripped and the barrier between interior and exterior is eliminated.The wind go directly inside the room and destroy everything inside.

These vulnerabilities allow water to seep into your home, causing immediate and long-lasting damage to your property and belongings.

hurricane destroy-in China

What’s hurricane proof glass?

Heat treated monolithic glass cannot be used as hurricane proof glass,even through tempered glass strength is 3-5 times higher than normal float glass,but as it can be break into fragment after broken,the fragment will cause further injury to people when the hurricane comes with big storm and wind.

tempered glass breakage -hurricane proof glass

So the hurricane proof glass must meet several requirement:

1. High strength and Difficult to break.
2. Glass keep integrity and not be penetrated after breaking.

For hurricane windows,the glass and window frame must be fixed and won’t fall in the wind.Thus hurricane proof glass can be classified into 3 types:

1. 
   

   PVB laminated glass.

Of course the PVB laminated glass here is tempered laminated glass with polyvinyl butyral.Tempered glass itself has high strength and even one piece broken in the hurricane,the interlayer can keep the glass overall integrity,meanwhile work as a barrier to prevent the inner piece glass been impacted .The PVB interlayer also prevent the glass been penetrated.

2. 
   

   SGP laminated glass.

PVB laminated glass will collapse once the 2 piece glass all broken,the PVB  interlayer is soft and has low shearing modulus,cannot hold the broken glass.

SGP laminated glass has high strength.SGP laminated glass bearing capability is 2 times that of PVB laminated glass,but the bending deflection of SGP laminated is only 1/4 of PVB laminated glass under the same thickness and load condition.
The tearing strength of SGP interlayer is 5 times higher than PVB film,even if the glass breaks,the SGP can also stick the glass and form a temporary structure while keeping small bending deformation,it can withstand a certain amount of load and whole piece laminated glass won’t fall or deform. Laminated glass processed with SGP interlayer film can effectively block damage to buildings when a hurricane strikes. it can greatly improve the impact resistance of safety glass. Performance, anti-theft, anti-riot performance and anti-disaster performance.

Learn more:PVB Laminated glass VS SGP laminated glass

3. 
   

   Polycarbonate laminated glass.

PC board is not easy to break, and its compressive strength is 250 times that of float glass, and it is 50-100 times stronger than that of tempered laminated glass. Even if it is hit with a hammer, there is no risk of breakage. The total area of the enterprise can accept a crash compressive strength of 91kgf-cm/cm, and a tensile strength of 739kgf/cm^2.

Polycarbonate laminated glass are usually used as anti intrusion glass,and bulletproof glass,so it has the highest strength against hurricane,but its price is extremely high.

Below video offered by Rizhao Fangding which shows the excellent safety performance of PC laminated glass.

Hurricane proof glass costs

1. PVB Tempered laminated glass: Typically laminated glass combination is 10+1.52PVB+10 ,now exw price is about USD50/SQM. Thicker glass and PVB interlayer will cause higher price.
2. SGP laminated glass: It depend on the SGP interlayer thickness, 6+0.89SGP+6 exw price is USD65/SQM,while 6+1.52SGP+6 exw price is USD95/SQM.
3. PC laminated glass:the extra costs is PC board price, usually USD30-50/SQM higher than same combination glass without PC board.

Despite simple laminated glass ,the hurricane resistant glass also can be made into laminated insulated glass to increase the glass thermal insulation performance.All kinds of low e coatings,warm edge spacer,argon can also be added to further decrease the glass U value.

Hurricane resistant glass can not only been used in glass curtain wall,glass skylight,railings,windows&doors,but also used as structural glass applications,for example glass stairs,floors,glass bridge,and special glass for its awesome safety performance:Bulletproof glass,anti-intrusion glass etc.

Windows frames requirement for hurricane resistant windows

The glass is only part of hurricane proof windows,the combination of glass and the frame is your good protector against the storms.The windows water tightness,air tightness and wind resistance are the most important points.

Water tightness:

when the doors and windows face the storm, they can still keep the interior dry, and there is no trouble of water leakage. Among the doors and windows of various materials, aluminum alloy doors and windows have better water tightness.

watertightness of hurricane proof window

Wind resistance:If a high-impact force can knock glass out of its fitting, then rain, wind, and debris will enter through the frame space. In extreme cases, your entire window could be pushed through, letting Mother Nature directly into your home mid-storm.

Heavy duty framing and strong enough installation is the most important factor protecting your property,so identify and selecting the right hurricane windows manufacturer and supplier is essential ,especially when the windows costs is extremely high.

Another point to consider is the surface treatment of your windows frames,seashore airs always contains salt and other component that cause corrosion on your frame and decrease it’s strength,and affect the appearance.

hurricane proof folding doors-morn

Morn is your turnkey hurricane proof glass manufacturer and supplier in China,if you got any hurricane proof glass requirement,contact us,let’s work together to protect your house.