Concrete Slab Load Transfer Apparatus

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Solution Overview

Problem

The existing methods for constructing concrete roadways with numerous joints are inefficient, leading to increased costs and time due to the high number and placement of dowels and baskets required for load transfer and connection, particularly when trying to distribute the weight of vehicles across multiple slabs to prevent wear and deterioration.

Innovation Solution

A concrete slab load transfer and connection apparatus that simultaneously serves to position dowels for load transfer between longitudinally adjacent slabs and connect transversely adjacent slabs, using a basket configuration with load transfer plates and slab connection members to form contraction joints, allowing for efficient distribution of vehicle weight across multiple slabs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional separate dowels and baskets are used for load transfer and connection at each joint, then load transfer between slabs is achieved, but the number of components and construction complexity increases significantly

Engineering Contradiction:
Improveload transferVSAvoidnumber of dowels and baskets
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple separate components (dowels for load transfer and baskets for connection) into a single integrated apparatus. The load transfer dowels are positioned within a basket structure, allowing both functions to be achieved with one placement operation rather than requiring separate components at each joint location.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The basket structure serves multiple functions simultaneously: it acts as a support structure for positioning dowels, provides connection between slabs, and enables load transfer. This multi-functional design reduces the total number of components needed compared to using separate dedicated components for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If numerous joints are formed in concrete roadways to distribute vehicle weight, then wear and deterioration of individual slabs is reduced, but construction time and costs increase

Engineering Contradiction:
Improvewear distributionVSAvoidconstruction time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The apparatus is positioned on the grade or subsurface before concrete is poured, allowing dowels and baskets to be pre-placed in correct locations. This preliminary positioning eliminates the need for subsequent drilling and installation operations after the concrete has cured, significantly reducing construction time while still achieving the desired joint distribution for wear reduction.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

By combining load transfer and connection functions into a single apparatus that is placed before concrete pouring, the construction process is streamlined. One placement operation achieves what would otherwise require multiple separate steps, reducing overall construction time while maintaining the beneficial wear distribution effects of numerous joints.

Inventive Principle:
Principle #5Merging (Combining)

3Stability of the object's composition

If tie bars are used to connect adjacent concrete slabs, then the slabs move together, but the connection strength and load transfer capability are insufficient

Engineering Contradiction:
Improveslab connectionVSAvoidload transfer capability
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The apparatus uses dowels made from materials with high strength properties, such as steel or fiber-reinforced polymers, to provide both connection and load transfer capabilities. The combination of the basket structure and dowel materials creates a composite system that exceeds the performance of tie bars alone, achieving both slab connection and superior load transfer capability.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3619359B1Concrete slab load transfer and connection apparatus
Publication Date: 2024.07.17 ILLINOIS TOOL WORKS INC
  • EP3619359B1 patent drawingFigure 1
  • EP3619359B1 patent drawingFigure 2A
  • EP3619359B1 patent drawingFigure 2B

AI summary

A concrete slab load transfer and connection apparatus for a cast-in- place concrete slab, comprising: a plurality of load transfer dowels 240, 740; a basket 210 or a plurality of baskets 710 supporting the load transfer dowels 240, 740; and a plurality of slab connection members 250, 252 forming part of or connected to the basket 210, or a plurality of slab connection members 460, 770 connecting the plurality of baskets 710.