What are the problems of fireproof glass in practical application?

Although fireproof glass has been widely used in buildings, there are still many blind areas in practical application, such as how to correctly use fireproof glass, which type of fireproof glass to use, and which parts can use fireproof glass.



At the same time, many construction units, design units and construction units have misunderstandings in understanding and use. They believe that as long as fire-proof glass is used, it can be used as a fire separation, and as long as the partition wall made of fire-proof glass can meet the fire resistance limit requirements. Our supervisors also have a lot of vague understanding about this in daily approval and inspection, and do not know how to grasp it. This paper briefly introduces and analyzes the problems existing in the use of fireproof glass and partition wall in construction engineering.




Although fireproof glass has been used for a long time, there are still some problems that can not be ignored in practical application and supervision:

1. Fireproof glass and fireproof glass partition wall are not divided

Some buildings need both fire separation and beautiful and transparent in design, and the fireproof glass partition wall will be solved as a fire separation measure, such as the partition wall of boutique in performance-based commercial pedestrian street, the glass firewall in large commercial space, the viewing window of viewing shaft, etc. However, designers often mark it as fire-proof glass instead of fire-proof glass partition wall on the drawing, while fire auditors generally only propose to mark the fire-proof glass partition wall for several hours, and do not require designers to explain the detailed node construction method drawing of fire-proof glass partition wall. In actual construction, the common practice is that the construction party purchases fire-proof glass according to the design requirements, fixes the fire-proof glass in the frame according to the practice of ordinary glass partition wall, and injects glass glue into the glass joint. It is simply considered that the splicing of fire-proof glass is the fire-proof glass partition wall, which meets the fire-fighting requirements, and the test report of fire-proof glass can be submitted during acceptance.

All these ignore that the fireproof glass partition wall is composed of fireproof glass, frame, sealing material, cushion block and other fireproof components, which is a complete system. Fireproof glass is only an integral part of fireproof glass partition wall. It must be combined with inlaid frame and fireproof sealing materials to form fireproof glass partition wall and meet the corresponding fire resistance limit standard of the specification.

2. Problems needing attention when adding spray protection to fireproof glass

Relevant experiments at home and abroad show that the selection of appropriate water spray system protection can effectively prolong the time when a single piece of fire-proof glass reaches the loss of heat insulation and street irradiance, effectively prolong the fire-proof and heat insulation time and ensure personnel evacuation. At present, this design is widely used in the performance-based design of large commercial pedestrian streets, and the single-chip non insulated fireproof glass water spray system plays a role in heat insulation. The key to this kind of engineering practice is the water distribution effect of spray protection, because the experiment shows that once the spray protection is lost, the single fireproof glass will soon lose the function of smoke and fire prevention.

However, there are many problems in the design and construction. For example, some shops on both sides of the commercial pedestrian street directly make the decoration modeling on the fireproof glass, which affects the water distribution effect of the sprinkler; Some install the nozzle under the decorated brand door, which affects the heat collection of the nozzle; Some door heads are installed between the fire-proof glass and the nozzle, resulting in shielding; Some construction units do not set the pipeline of the spray protection system separately and share the same pipeline with other sprays, resulting in the spray water volume and duration not meeting the design requirements; Some construction units use the wrong type of sprinkler. In short, during construction, it should be ensured that the sprinkler can timely and effectively protect the fireproof glass for separation, which should be paid attention to.

3. Misunderstandings in the design and construction of fireproof glass partition wall

At present, many design units do not design engineering practices, and the construction units have misunderstandings about the test report of fire-proof glass. They think that as long as the selected fire-proof glass has a test report, they ignore that the fire-proof test is not a test report of only a few pages, but a complete set of systematic information describing the detailed size, material use and fire performance of the fire-proof system. The drawing of safety glass in buildings Part 1: fireproof glass (gb15763.1-2009) focuses on the types, thickness, shape, size, assembly details, node drawings, and even the size and position of fixing screws of various frame materials and accessories used in the system during the test. As specified in the fire resistance performance in article 7.3, the fire resistance size of the sample of fire-proof glass shall be selected as the large size actually used for the test, and shall not be less than 1200mm × 700mm。

The fixed frame and installation method used in the experiment shall be the same as those used in the actual project, and the fixed frame and installation method shall be recorded in drawings or other equivalent methods. However, in the actual project, in order to achieve a good visual effect, the construction unit often selects the size of the glass that exceeds the size of the fire-proof glass submitted for inspection in the inspection report, and the fixed frame and installation method of the fire-proof glass do not adopt the fixed method in the inspection report, resulting in the inability to determine its fire resistance limit during acceptance. The construction unit needs to re submit the fire-proof glass for inspection according to the actual size of the project, If it fails to pass the test, the construction unit needs to re select and purchase fireproof glass or re install it, resulting in a lot of waste. Therefore, the construction unit and the construction unit shall send the selected products together with the construction methods to be selected to the national professional testing department for inspection before construction, and then carry out the construction after passing the inspection.

4. Problems in fire supervision

Some supervisors mistakenly believe that a door made of fireproof glass is a fireproof door, a partition made of fireproof glass is a fireproof glass partition, and a window made of fireproof glass is a fireproof window. It should be clearly understood that fireproof glass, fireproof glass partition, fireproof door and fireproof window are completely different fire-fighting products, and the corresponding inspection report should be checked, and the fireproof door should also have a type inspection report.

In the inspection, we should not simply ask about the fire resistance limit of the fire-proof glass, but carefully check whether the size of the fire-proof glass in the inspection report is consistent with the on-site practice. The fire endurance of fire-proof glass partition wall also depends on the frame structure and the connection and fixation mode between glass and frame. During the inspection, it should also check whether the engineering practice of fire-proof glass partition wall is installed and constructed according to the construction process provided by the manufacturer, such as thermal insulation frame system. Because composite thermal insulation fire-proof glass is used, the colloid in the glass will foam and expand when heated, Therefore, a certain gap should be left between the glass and the frame during installation; The non insulated frame system uses single piece of fire-proof glass. In a fire, the single piece of fire-proof glass will soften and sag, so the frame system should be tightly clamped with glass and no gap should be left.