Sleeper Pad With Grooved Fiber Layer For Dry Concrete Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solutions for connecting textile fiber structures to concrete bodies, such as railway sleepers, face limitations in achieving reliable bonding, especially with relatively dry fresh concrete, leading to defects like pumping effects and inadequate tear-off strength due to limited penetration of cement-water suspension and restricted elasticity behavior.
Innovation Solution
A pad for concrete bodies, featuring a tangled fiber layer that is locally solidified through thermal treatment or adhesive application, allowing it to penetrate dry concrete effectively by forming groove-like depressions which enhance the bond strength and resilience, enabling better integration with the concrete.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a random fiber layer is used to connect the pad to concrete, then the connection should provide elasticity and bonding, but the cement-water suspension penetrates insufficiently into the fiber layer, leading to inadequate bond strength and pumping effects
Solution Approach 1:
The fiber layer is locally modified by forming groove-like depressions and solidifying specific areas to create zones with different penetration characteristics. The solidified areas provide anchoring points that enhance cement-water suspension penetration and bond strength, while the remaining areas maintain elasticity. This local differentiation resolves the contradiction by providing both strong bonding and reliable connection without requiring complete penetration throughout the entire fiber layer.
Solution Approach 2:
The fiber layer is pre-treated by forming depressions and solidifying areas before application to the concrete surface. This preliminary structuring creates predetermined pathways and anchoring points that facilitate better penetration and bonding during the subsequent concrete application, eliminating the need for deepening areas around solidified points and ensuring reliable connection from the outset.
2Adaptability or versatility
If the fiber layer is made resilient to maintain elasticity behavior, then it can adapt to concrete movement, but it cannot penetrate dry concrete effectively, resulting in insufficient bond
Solution Approach 1:
The fiber layer exhibits different properties in different locations: solidified areas provide penetration and bonding strength, while the remaining areas maintain resilience and elasticity. This local differentiation allows the fiber layer to simultaneously achieve effective penetration into dry concrete and maintain the elasticity behavior needed for adaptability to concrete movement.
Solution Approach 2:
The fiber layer is segmented into solidified areas and non-solidified areas, each serving distinct functions. The solidified areas act as anchoring points for penetration and bonding, while the non-solidified areas provide elasticity and adaptability. This segmentation resolves the contradiction by allowing different regions to fulfill different requirements without compromising either function.
3Strength
If the fiber layer is solidified to improve penetration into dry concrete, then bond strength increases, but the fiber layer loses some of its random fiber behavior and resilience
Solution Approach 1:
Only specific local areas of the fiber layer are solidified to create anchoring points for penetration and bonding, while the majority of the fiber layer maintains its random fiber structure and resilience. This localized solidification approach enables the fiber layer to achieve improved bond strength without sacrificing the overall resilience needed for adaptability to concrete movement.
Solution Approach 2:
The fiber layer is divided into solidified segments and non-solidified segments. The solidified segments provide bonding strength and penetration capability, while the non-solidified segments preserve random fiber behavior and resilience. This segmentation allows the fiber layer to simultaneously achieve both bond strength and adaptability by distributing different functions across different segments.
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
The solution significantly improves tear-off strength between the fiber layer and concrete, achieving values twice that of conventional methods and ensuring reliable bonding across the entire surface, even with extremely dry concrete, while maintaining the fiber layer's resilience.
Implementation Method 1
This connection can be thermally induced in that the adjacent fiber loops and fiber ends of the random fiber layer are heated in some areas, melt and connect on cooling.
Implementation Method 2
A solidification can, however, just as well take place, for example, by local application of adhesive, which then runs downwards through the random fiber layer and solidifies the grasped fibers by connecting them to one another.
Implementation Method 3
Known nonwovens and nonwoven-like random fiber materials (connecting media) allow only limited penetration of the cement-water suspension into the connecting medium in the case of vibration-assisted application on relatively dry fresh concrete of the sleepers.
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a pad (10) for a concrete body (12), in particular for a sleeper, comprising a resilient plastics layer (20) having an upper side, and comprising a fibre layer (14) arranged on the upper side of the resilient plastics layer (20) and connected to the resilient plastics layer (20). The fibre layer (14), on its upper side facing away from the plastics layer (20), has in particular groove-like indentations (16), which have a base situated between the upper side of the fibre layer (14) and the upper side of the plastics layer (20) and flanks protruding from the base. The fibre layer (14) is reinforced in its edge regions (22) adjacent to the flanks.