Technical specification for installation of tunnel fireproof board

1、 Core standard basis

The installation of tunnel fireproof boards must strictly comply with the national mandatory standard "GB 28376-2012 Tunnel Fireproof Protection Board", which is applicable to the fireproof protection system on the surface of concrete structures in highway and urban transportation tunnels. Railway tunnels can refer to this standard for implementation.

Fire resistance requirements:

BZ class (standard heating curve): fire resistance limit ≥ 2.00 hours

HC class (HC heating curve): fire resistance limit ≥ 2.00 hours

RABT type (RABT heating curve): heating section ≥ 1.50 hours, cooling section ≥ 1.83 hours

Material requirements: The board should be made of inorganic non combustible materials (such as calcium silicate board, magnesium silicate board, high-density fiber cement board), with a surface density of ≤ 24kg/㎡, dry bending strength of ≥ 6MPa, and water absorption rate of ≤ 12.0%.

Status update: This standard has been revised since 2025 (Plan No.: 20251022-Q-906), and the revised version will be extended to the scope of application of steel-concrete composite structures. After the new version is released, it will replace the current standard.

2、 Installation process flow

Adopting a composite installation system of "keel system+anchoring+sealing", the construction process is as follows:

|Steps | Operation Content | Technical Requirements|

|1 | Base treatment | Remove debris, oil stains, and floating slurry from the concrete surface, repair holes, and ensure that the flatness error is ≤ 5mm|

|2 | Bullet line positioning | Set the horizontal centerline based on the top of the tunnel sidewall; The spacing between the positioning points of the support is ≤ 3m, and it should be calibrated every 10m with an error of ≤ 3mm|

|3 | Install L-shaped stainless steel supports | Use M10 × 100 stainless steel expansion bolts to fix them to the tunnel side walls. The supports must be horizontal and adjacent supports must not be collinear, leaving room for adjustment|

|4 | Install aluminum alloy keel system | - Top keel: fixed to the upper edge of the top plate - Horizontal seam keel: clamps the upper and lower plate seams - Bottom keel: supports the bottom plate - Vertical keel: used for vertical seam closure - L-shaped keel: enhances the bonding strength between the plate and the keel|

|5 | Plate installation | - Install in sequence from bottom to top - Paste double PE adhesive strips (width ≥ 10mm) on the contact surface between each plate and the keel - The plate is embedded through the keel slot and lightly pressed to ensure that the adhesive strip is evenly stressed|

|6 | Joint treatment | - Vertical board joint width ≥ 10mm to avoid thermal stress concentration - Horizontal joints are pressed together by horizontal joint keels without rigid connections|

|7 | External corner treatment | Use specialized aluminum alloy external corner profiles to wrap and ensure that there is no risk of cracking at the corners|

|8 | Adjustment and acceptance | Check the three elements of "horizontal flatness, vertical flatness, and surface flatness", with a height difference between panels of ≤ 1mm and no warping, bubbling, or missing corners|

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3、 Fixed method and material requirements

Anchor system:

Expansion bolt: made of M10 × 100 stainless steel material, used for rigid connection between L-shaped supports and tunnel walls, with a drilling depth of ≥ 80mm and a hole diameter of 5.5-7.7mm.

Keel connection: M8 × 30 stainless steel bolts+flat washers+spring washers, used for flexible connection between horizontal keels and supports, allowing for thermal expansion and contraction displacement.

Adhesive material:

PE tape: made of high-density polyethylene material, with a temperature resistance of -40 ℃~120 ℃ and a compression rebound rate of ≥ 80%. It is used for elastic sealing between boards and keels, and has functions of fire prevention, sound insulation, and shock absorption.

Prohibited use: direct bonding of cement mortar, ordinary glue, non flame retardant sealant.

4、 Specification for Fire Sealing and Joint Treatment

Board seam treatment:

Vertical joints shall be reserved with a minimum of 10mm and shall not be filled tightly to accommodate structural deformation.

Sealing of through holes (such as pipeline and cable crossings):

Using a combination of mineral wool backing (density ≥ 100kg/m ³) and elastic organic fireproof sealing materials (such as fireproof mud and fireproof sealant) for sealing.

Sealing thickness ≥ 200mm, with the same fire resistance limit as the structure.

Deformation joint treatment:

Steel support plates (thickness ≥ 1.5mm), mineral wool filling, and elastic fireproof sealing materials are used to cover the settlement and expansion joints to ensure fire integrity under dynamic conditions.

5、 Construction Atlas and Engineering Reference

In the National Building Standard Design Atlas 19CJ60-5 "Fire Protection, Explosion proof, and Explosion Relief Board Building Construction", a detailed drawing of the "2h (RABT) Tunnel Fire Protection Construction" is provided, covering:

Detailed drawing of keel node

Expansion bolt layout diagram

Fireproof sealing structure for fireproof boards, air ducts, and curtain walls

Installation method of irregular plates for curved tunnels

This atlas provides authoritative visual basis for design and construction.

6、 Precautions for on-site construction

Environmental requirements: Construction temperature ≥ 5 ℃, humidity ≤ 85%, avoid working in rainy or condensation environments.

Safety protection: High altitude operations must wear safety belts and helmets, use mobile platform frames, and strictly prohibit stepping on unsecured boards.

Acceptance criteria:

Appearance: No cracks, delamination, bubbling, or missing corners

Installation: The spacing between the keels is ≤ 600mm, the bolts are not loose, and the rubber strip is continuous without breakage

Fire resistance performance: The material testing report shall prevail, and destructive testing shall not be conducted on site.

Shandong Huaneng Insulation Materials is a pipeline insulation manufacturer in Linyi. As an integrated insulation and decoration manufacturer in Shandong, our main products include integrated insulation and decoration, pipeline insulation, exterior wall insulation materials, extruded polystyrene board, thermosetting polystyrene board, and rubber insulation. If you need it, you can contact us by phone.