Concrete Lining of Microencapsulated Self-fireproof Tunnel

Abstract

The invention provides a self-fireproof tunnel concrete lining structure based on microcapsule technology, which includes a common layer and a self-fireproof layer, the common layer is a conventional concrete layer, and the self-fireproof layer is composed of reinforcing fibers, anti-burst fibers and thermal Concrete is made of molten microcapsules, and the hot-melt microcapsules include a capsule shell and a fireproof medium filled inside. Compared with the ordinary reinforced concrete lining structure, the present invention gives full play to the fireproof ability of the tunnel lining structure itself, realizes the synchronism of explosion prevention and heat insulation, and the combination of fire prevention and load bearing without changing the structure size and reducing the structural strength and rigidity. Synergistic effect and automatic fire protection under fire heat trigger, good durability, high long-term economic benefits, suitable for full life cycle fire protection design of tunnel concrete lining.

Description

technical field [0001] The invention relates to a tunnel concrete lining structure, in particular to a microcapsule self-fireproof tunnel concrete lining structure. Background technique [0002] Fire is one of the main disasters that threaten the safe operation of tunnels. Among the more than 100 major tunnel fire accidents at home and abroad (such as the construction site fire of the Great Belt Tunnel in Denmark in 1994; the fire in the English-French Channel Tunnel in 1996; the fire in the Yanhou Tunnel of Jinji Expressway in Shanxi in 2014, etc.), due to the high fire temperature ( It can reach above 1000°C), the heating rate is fast (with the characteristics of thermal shock), and the duration is long. The fire not only caused heavy casualties and facility damage, but also caused serious damage and damage to the lining structure ( figure 1 ), such as concrete high-temperature bursting, protective layer peeling, steel bar exposure failure, concrete durability reduction, ...

AI Technical Summary

Problems solved by technology

The construction of fireproof boards, fireproof spray coatings, water spraying and other methods all require passive fire prevention with the help of forces other than the lining structure itself, and the first two will block the lining surface, hindering the lining structure during the operation period (surface leakage, cracking, etc.) ) and the assessment of healthy service status; in addition, under the action of vehicle exhaust gas, wet water seepage, piston wind pressure or vehicle vibration load, it is easy to fall off or fail; due to the limitation of technical level, the existing fireproof board and fireproof spray coating It is difficult to meet the requirements of the whole life of the project, such as 100 years, generally need to be updated 2-3 times in the whole life of the project, which increases the maintenance cost

[0011] 2. Failure to effectively realize the synchronization of explosion prevention and heat insulation

The above-mentioned anti-cracking methods can effectively control the high-temperature cracking of concrete, but they cannot effectively weaken the transfer of heat to the tunnel lining

[0012] 3. Failure to effectively realize the synergy between fire protection and load bearing

Concrete mixed with phase change energy storage materials has low strength and weak bearing capacity; while heat insulation barriers such as fireproof boards cannot be used as an effective load-bearing part of the lining structure

[0013] 4. Failure to effectively realize automatic fire protection under fire heat trigger

[0014] 5. In order to install fire-proof boards and fire-proof spray coatings, it is necessary to expand the excavation section of the tunnel, which increases the project cost and quantity

It is estimated that the installation of fireproof boards and fireproof coatings will increase the diameter of the tunnel by 8-10cm, and correspondingly increase the excavation workload by 1.5%-2%. In addition, the use of fireproof boards and fireproof coatings will affect the fans, signal facilities, and traffic in the tunnel. Installation of lights, monitoring equipment, etc.

[0015] 6. The installation (spraying) of fireproof board and fireproof spray paint increases the construction time of the project

Images