Concrete Tunnel Fire Protection Cladding with Embedded U-Clamps
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Solution Overview
Problem
The existing methods for constructing tunnel walls using fire protection panels result in insufficient bonding between the panels and concrete, leading to delamination, especially around the panel edges, due to moisture gradients causing the panels to shrink and detach from the concrete surface.
Innovation Solution
The use of clamps, such as U-clamps made of bent metal wire or sheet metal, are driven into the fire protection panels from the outer surface and protrude beyond the panel surface to be embedded in the concrete during pouring, ensuring a secure connection with the concrete wall.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fire protection panels are attached to formwork and concreted onto tunnel wall, then fire protection is provided, but delamination occurs around panel edges due to moisture gradient causing panel shrinkage
Solution Approach 1:
Clamps are driven into the fire protection panels from the inner surface before concreting takes place. The clamps protrude through the panel to the outer surface, where they will be embedded in the concrete. This preliminary action ensures that the clamps are already positioned and secured in the panels before the concrete is poured, preventing delamination during the bonding process.
Solution Approach 2:
Metal clamps serve as an intermediary element between the fire protection panels and the concrete. The clamps are driven into the panels and protrude through them to be embedded in the concrete, creating a mechanical connection that bridges the two materials. This intermediary component prevents direct contact issues between the panel and concrete, eliminating the delamination problem caused by moisture gradients.
2Reliability
If screws are driven into fire protection panels from inner surface before casting, then anchoring in concrete is achieved, but screw distribution across entire panel surface increases complexity
Solution Approach 1:
Instead of distributing fasteners across the entire panel surface, the invention concentrates the fastening action at the panel edges. Clamps are driven into the panels along the edge regions, where they provide sufficient anchoring through the concrete. This local approach maintains bond strength while significantly reducing the number of fasteners needed compared to full-surface distribution.
Solution Approach 2:
The panel edge region is identified as the critical zone for bonding, and clamps are concentrated in this segmented area rather than being uniformly distributed across the entire panel. This segmentation allows the bonding function to be performed effectively at specific locations (edges) rather than requiring coverage of the entire surface, reducing overall complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method effectively prevents delamination of fire protection panels by maintaining a strong bond with the concrete, even under various operational loads, while reducing installation costs and ensuring a secure, permanent attachment.
Implementation Method 1
clamps, in particular U-clamps (8), made of bent metal wire (9) or sheet metal, are driven into the fire protection panels (6) from the outer panel surface (6b)
Implementation Method 2
the fire protection panels initially absorbing some of the mixing water during concreting. After demoulding, the fire protection panels dry out from the exposed, inner surface of the panel, leading to a moisture gradient
Data Source
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AI summary
The present invention relates to a building ceiling or building wall, in particular a tunnel ceiling or tunnel wall, with a wall made of concrete and cladding panels, preferably fire protection panels, concreted thereto, as well as to a building, in particular a tunnel, with such a building ceiling or building wall and to a method for producing the building ceiling or the building wall, in particular the tunnel ceiling or tunnel wall.