U-shaped glass curtain walls are popular with owners and architectural designers for their low heat-transfer coefficient, good thermal insulation, consistent color, straightforward installation, fire performance, economy, and environmental benefits.

01.Introduction to U-shaped glass

Architectural U-shaped glass, also called channel glass, is produced continuously by rolling and then forming the glass. It takes its name from its U-shaped cross-section. Many types are available, offering light transmission while obscuring views, thermal and sound insulation, and greater mechanical strength than ordinary flat glass. Straightforward installation, distinctive architectural effects, and reduced use of light-metal framing support a wide range of applications.

The products passed inspection by the glass quality supervision and inspection center in accordance with building materials industry standard JC/T 867 -2000, “U-shaped glass for buildings.” Their technical specifications were formulated with reference to German industrial standards DIN1249 and 1055.

The products were included in the Yunnan New Wall Materials Product Catalogue in February 2011.

02.Scope of application

It can be used for non-load-bearing exterior walls, partitions, and roofs in airports, stations, sports halls, factories, office buildings, hotels, homes, greenhouses, and other industrial or civil buildings.

03.Reference Standards and atlases

Building materials industry standard JC/T 867-2000, “U-shaped glass for buildings”

German industrial standards DIN1055 and DIN1249

Architectural Standard Design Atlas 06J505-1: Exterior Decoration (I)

04.Classification of U-shaped glass

By color: colorless, spray-colored, or film-colored. Colorless glass is the most commonly used.

Surface finishes: embossed, smooth, and fine-textured. Embossed finishes are commonly used.

Classification by strength and treatment: ordinary, toughened, film-coated, reinforced-film and insulation-filled glass.

05.Architectural design application

As wall material, U-shaped glass can be used in building interior wall, exterior wall, partition and other parts. External walls are generally used in multi-storey buildings, the height of the glass depends on the wind load, the height of glass distance and glass connections. The data of German industrial standards DIN-1249 and DIN-18056 are provided in this special issue (Schedule 1) for the design of multi-storey and high-rise buildings. The node diagram of U-shaped glass exterior wall is specially described in the architectural standard design atlas 06J505-1 external decoration (I) and this special issue.

U-shaped glass is non-combustible. Its fire-resistance duration is 0.75 h for a single layer of 6mm-thick glass. Where special requirements apply, the design or fire-protection measures should comply with the relevant codes.

U-shaped glass can be installed in single or double layers, with or without ventilation gaps. This publication covers two arrangements: a single row with flanges facing outward or inward, and a double row with flanges paired at the joints. Any other arrangement should be specified separately.

06. Installation method

Pre-installation preparation: the contractor must understand the regulations and basic methods for installing U-shaped glass and provide operators with short-term practical training. Before entering the site, sign the Safety Guarantee Agreement and incorporate it into the project contract.

Installation planning: before entering the construction site, prepare an installation procedure suited to the project. Give every operator the basic requirements and ensure that they understand and can follow them. Organize ground-level training where necessary, particularly on mandatory safety procedures.

Basic installation requirements: purpose-made aluminum profiles are normally used. Stainless-steel or ferrous-metal profiles may also be used at the customer’s request. Metal profiles require effective corrosion and rust protection. Secure the frame firmly to the wall or building opening, with at least 2 fixing points per linear meter.

Installation height calculation: see attached figure (see profile glass installation height table) . U-shaped glass is installed in the four-square box hole in the transparent wall, the length of glass for the height of the box hole reduced by 25-30 mm, width can not consider building modulus, because U-shaped glass can be arbitrarily cut. 0-8m scaffolding. High-rise installation generally using hanging basket method, safe, fast, practical and convenient.

07.Installation process

Fix the aluminum frame to the building with stainless-steel bolts or rivets. Carefully clean the inner surface of the U-shaped glass before inserting it into the frame.

Cut the cushioning plastic pieces that stabilize the glass to the required lengths and place them in the fixed frame.

When the U-shaped glass is installed to the latter piece, and the width allowance of the hole can not be installed into the whole piece of glass, the U-shaped glass can be cut along the length direction to meet the remaining width. Installation should be cut off the u-glass first into the border, and then according to Article 5 requirements for installation.

For the final three U-shaped glass sections, insert two into the frame first, then fit the third to close the assembly.

Allow suitable thermal expansion gaps between U-shaped glass panels, especially in areas with large seasonal temperature differences.

When the height of U-shaped glass is less than 5 m, the permissible deviation of the verticality of the border is 5 mm; when the horizontal width of U-shaped glass is more than 2 m, the permissible deviation of the horizontal component is 3 mm; when the height of U-shaped glass is less than 6 m, the permissible deviation of the horizontal component is 3 mm, the allowable deflection is less than 8mm.

Cleaning: after completing a wall, remove marks left on the glass surface.

Insert an elastic strip into the gap between the frame and glass. Its contact width against both the glass and the frame must be at least 12mm.

Fill the joints between frames and glass, between adjacent glass panels, and between frames and the building with an elastic glazing sealant or silicone sealant.

Loads carried by the frame should be transferred directly to the building structure. U-shaped glass walls are non-load-bearing and must not carry these loads.

When installing the glass, the inside surface should be wiped clean. After installation, the dirt on the outside surface should be wiped clean.

08. Transport

Glass is normally transported by truck from the factory to the construction site. Level ground and suitable storage space may be difficult to find on site, but U-shaped glass must be kept safe and clean. Appropriate cleaning measures are recommended.

09. Removal

The manufacturer loads U-shaped glass with a crane, and the construction contractor is responsible for unloading it. Standardized unloading procedures are recommended to prevent damage caused by improper handling, damaged packaging or uneven ground.

In the case of wind load, the wind pressure strength of u-glass is usually determined by calculating its maximum service length: l-u-glass to maximum service length, md-u-glass bending stress, the bending modulus of n/mm2WF1-u glass wing (see table 13.2 for details) , cm3P-wind load standard value, the bottom width of KN/m2A-u glass wing, and the bending modulus of M13.2 u glass with different specifications.

The bending modulus of different installation methods should be taken

When the wing faces the direction of force, the bending modulus of the base plate WST is adopted.

The bending modulus of the wing, WF1, is adopted when the bottom plate faces the direction of loading.

When the U-type glass is installed, the integrated bending modulus of the integrated value.

In cold winters, the large temperature difference between indoors and outdoors can cause condensation on the inner glass surface. For building envelopes with single- or double-row U-shaped glass, when the outdoor temperature is low and the indoor temperature is 20 ° C, condensation depends on both the outdoor temperature and indoor humidity.

10.Thermal insulation property

The heat transfer coefficient of double-layer U-shaped glass with different filling materials can reach 2.8 ~ 1.84 w/(m2? K) . In Germany's DIN18032 safety standard, U-shaped glass is classified as safety glass (our relevant standard has not been included in safety glass) , can be used for ball sports venues and roof daylighting. By strength calculation, the safety of U-shaped glass is 4.5 times that of ordinary glass. The strength of U-shaped glass with the same area as plate glass after installation is calculated by the area formula: AMAX = α (0.2t1.6 + 0.8)/Wk, which reflects the relationship between the area of glass and the strength of wind load. The U-shaped glass achieves the strength of the toughened glass equivalent area, while the two-wing sealant bonding constitutes the overall safety of the glass (safety glass in German industrial standard 1249-1055) .

Vertical installation of U-shaped glass in exterior walls