Concrete Expansion Joint with Interlocking Denticulated Edges
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing expansion joints in concrete floors, especially those subjected to heavy loads and temperature fluctuations, suffer from damage due to the hardness difference between steel joint profiles and vehicle wheels, leading to vertical tilting and edge damage, and require additional load transfer elements that increase complexity and material usage.
Innovation Solution
An expansion joint design featuring vertically oriented corrugated plates with denticulated edges out of phase to interlock and provide load transfer, eliminating the need for additional load transfer elements by utilizing the dents at the edges of the concrete slabs for both vertical fixation and horizontal displacement, with anchoring dowels for stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If steel joint profiles are used in expansion joints, then structural strength and load transfer are improved, but edge damage from vehicle wheels increases due to hardness difference
Solution Approach 1:
The invention merges the joint profile with the concrete slabs by having the profile integrally formed with the slabs as a single piece, eliminating the need for separate steel load transfer elements that cause damage through hardness differences
Solution Approach 2:
The invention changes the material parameter of the joint profile to match the concrete slabs, using the same concrete material with identical hardness characteristics, thereby eliminating the hardness mismatch that causes wheel and edge damage
2Reliability
If additional load transfer elements are added to prevent vertical tilting, then load transfer and stability are improved, but device complexity and material usage increase
Solution Approach 1:
The joint profile is merged with the concrete slabs as an integral structure, combining the functions of the slabs and the load transfer elements into a single unified component, thereby eliminating the need for additional separate elements
Solution Approach 2:
The joint profile serves multiple functions simultaneously: it provides load transfer, prevents vertical tilting through its rigid connection to both slabs, and maintains the expansion joint functionality, thereby eliminating the need for specialized additional load transfer elements
3Strength
If metal interlocking end plates are used, then load transfer is improved, but loosening over time occurs due to abrupt change in expansion coefficient
Solution Approach 1:
The invention changes the material parameter of the joint profile to match the thermal expansion coefficient of the concrete slabs, using the same concrete material throughout, thereby eliminating the abrupt change in expansion coefficient that causes loosening over time
Solution Approach 2:
The joint profile is made homogeneous with the concrete slabs by using the same concrete material, ensuring uniform thermal expansion characteristics across the entire structure and preventing differential movement that leads to loosening
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a expansion joint to bridge an expansion gap between two parts of concrete slabs used in floor construction, especially in the manufacture of concrete floors such as for example in industrial floors. Such expansion joints are evidently required to take up the inevitable shrinkage process of the concrete and to assure that the floor elements can expand or contract such as for example occur by temperature fluctuations and resulting in a horizontal displacement of the floor panels vis-à-vis one another.